| File: | root/firefox-clang/obj-x86_64-pc-linux-gnu/js/src/jit/./../../../../js/src/jit/RangeAnalysis.cpp |
| Warning: | line 476, column 9 Value stored to 'first' is never read |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
| 1 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| 2 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| 3 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| 4 | |
| 5 | #include "jit/RangeAnalysis.h" |
| 6 | |
| 7 | #include "mozilla/CheckedArithmetic.h" |
| 8 | #include "mozilla/MathAlgorithms.h" |
| 9 | |
| 10 | #include <algorithm> |
| 11 | #include <bit> |
| 12 | |
| 13 | #include "builtin/Math.h" |
| 14 | #include "jit/CompileInfo.h" |
| 15 | #include "jit/IonAnalysis.h" |
| 16 | #include "jit/JitSpewer.h" |
| 17 | #include "jit/MIR-wasm.h" |
| 18 | #include "jit/MIR.h" |
| 19 | #include "jit/MIRGenerator.h" |
| 20 | #include "jit/MIRGraph.h" |
| 21 | #include "js/Conversions.h" |
| 22 | #include "js/ScalarType.h" // js::Scalar::Type |
| 23 | #include "util/Unicode.h" |
| 24 | #include "vm/ArgumentsObject.h" |
| 25 | #include "vm/Float16.h" |
| 26 | #include "vm/TypedArrayObject.h" |
| 27 | #include "vm/Uint8Clamped.h" |
| 28 | |
| 29 | #include "vm/BytecodeUtil-inl.h" |
| 30 | |
| 31 | using namespace js; |
| 32 | using namespace js::jit; |
| 33 | |
| 34 | using JS::GenericNaN; |
| 35 | using JS::ToInt32; |
| 36 | using mozilla::Abs; |
| 37 | using mozilla::ExponentComponent; |
| 38 | using mozilla::FloorLog2; |
| 39 | using mozilla::IsNegativeZero; |
| 40 | using mozilla::NegativeInfinity; |
| 41 | using mozilla::NumberEqualsInt32; |
| 42 | using mozilla::PositiveInfinity; |
| 43 | |
| 44 | // [SMDOC] IonMonkey Range Analysis |
| 45 | // |
| 46 | // This algorithm is based on the paper "Eliminating Range Checks Using |
| 47 | // Static Single Assignment Form" by Gough and Klaren. |
| 48 | // |
| 49 | // We associate a range object with each SSA name, and the ranges are consulted |
| 50 | // in order to determine whether overflow is possible for arithmetic |
| 51 | // computations. |
| 52 | // |
| 53 | // An important source of range information that requires care to take |
| 54 | // advantage of is conditional control flow. Consider the code below: |
| 55 | // |
| 56 | // if (x < 0) { |
| 57 | // y = x + 2000000000; |
| 58 | // } else { |
| 59 | // if (x < 1000000000) { |
| 60 | // y = x * 2; |
| 61 | // } else { |
| 62 | // y = x - 3000000000; |
| 63 | // } |
| 64 | // } |
| 65 | // |
| 66 | // The arithmetic operations in this code cannot overflow, but it is not |
| 67 | // sufficient to simply associate each name with a range, since the information |
| 68 | // differs between basic blocks. The traditional dataflow approach would be |
| 69 | // associate ranges with (name, basic block) pairs. This solution is not |
| 70 | // satisfying, since we lose the benefit of SSA form: in SSA form, each |
| 71 | // definition has a unique name, so there is no need to track information about |
| 72 | // the control flow of the program. |
| 73 | // |
| 74 | // The approach used here is to add a new form of pseudo operation called a |
| 75 | // beta node, which associates range information with a value. These beta |
| 76 | // instructions take one argument and additionally have an auxiliary constant |
| 77 | // range associated with them. Operationally, beta nodes are just copies, but |
| 78 | // the invariant expressed by beta node copies is that the output will fall |
| 79 | // inside the range given by the beta node. Gough and Klaeren refer to SSA |
| 80 | // extended with these beta nodes as XSA form. The following shows the example |
| 81 | // code transformed into XSA form: |
| 82 | // |
| 83 | // if (x < 0) { |
| 84 | // x1 = Beta(x, [INT_MIN, -1]); |
| 85 | // y1 = x1 + 2000000000; |
| 86 | // } else { |
| 87 | // x2 = Beta(x, [0, INT_MAX]); |
| 88 | // if (x2 < 1000000000) { |
| 89 | // x3 = Beta(x2, [INT_MIN, 999999999]); |
| 90 | // y2 = x3*2; |
| 91 | // } else { |
| 92 | // x4 = Beta(x2, [1000000000, INT_MAX]); |
| 93 | // y3 = x4 - 3000000000; |
| 94 | // } |
| 95 | // y4 = Phi(y2, y3); |
| 96 | // } |
| 97 | // y = Phi(y1, y4); |
| 98 | // |
| 99 | // We insert beta nodes for the purposes of range analysis (they might also be |
| 100 | // usefully used for other forms of bounds check elimination) and remove them |
| 101 | // after range analysis is performed. The remaining compiler phases do not ever |
| 102 | // encounter beta nodes. |
| 103 | |
| 104 | static bool IsDominatedUse(const MBasicBlock* block, const MUse* use) { |
| 105 | MNode* n = use->consumer(); |
| 106 | bool isPhi = n->isDefinition() && n->toDefinition()->isPhi(); |
| 107 | |
| 108 | if (isPhi) { |
| 109 | MPhi* phi = n->toDefinition()->toPhi(); |
| 110 | return block->dominates(phi->block()->getPredecessor(phi->indexOf(use))); |
| 111 | } |
| 112 | |
| 113 | return block->dominates(n->block()); |
| 114 | } |
| 115 | |
| 116 | static inline void SpewRange(const MDefinition* def) { |
| 117 | #ifdef JS_JITSPEW1 |
| 118 | if (JitSpewEnabled(JitSpew_Range) && def->type() != MIRType::None && |
| 119 | def->range()) { |
| 120 | AutoJitSpewMessage msg(JitSpew_Range, " "); |
| 121 | def->printName(msg.printer()); |
| 122 | msg.append(" has range "); |
| 123 | def->range()->dump(msg.printer()); |
| 124 | } |
| 125 | #endif |
| 126 | } |
| 127 | |
| 128 | #ifdef JS_JITSPEW1 |
| 129 | static const char* TruncateKindString(TruncateKind kind) { |
| 130 | switch (kind) { |
| 131 | case TruncateKind::NoTruncate: |
| 132 | return "NoTruncate"; |
| 133 | case TruncateKind::TruncateAfterBailouts: |
| 134 | return "TruncateAfterBailouts"; |
| 135 | case TruncateKind::IndirectTruncate: |
| 136 | return "IndirectTruncate"; |
| 137 | case TruncateKind::Truncate: |
| 138 | return "Truncate"; |
| 139 | default: |
| 140 | MOZ_CRASH("Unknown truncate kind.")do { do { } while (false); MOZ_ReportCrash("" "Unknown truncate kind." , "./../../../../js/src/jit/RangeAnalysis.cpp", 140); AnnotateMozCrashReason ("MOZ_CRASH(" "Unknown truncate kind." ")"); do { MOZ_CrashSequence (__null, 140); __attribute__((nomerge)) ::abort(); } while (false ); } while (false); |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | static inline void SpewTruncate(const MDefinition* def, TruncateKind kind, |
| 145 | bool shouldClone) { |
| 146 | if (JitSpewEnabled(JitSpew_Range)) { |
| 147 | AutoJitSpewMessage msg(JitSpew_Range, " truncating "); |
| 148 | def->printName(msg.printer()); |
| 149 | msg.append(" (kind: %s, clone: %d)", TruncateKindString(kind), shouldClone); |
| 150 | } |
| 151 | } |
| 152 | #else |
| 153 | static inline void SpewTruncate(MDefinition* def, TruncateKind kind, |
| 154 | bool shouldClone) {} |
| 155 | #endif |
| 156 | |
| 157 | TempAllocator& RangeAnalysis::alloc() const { return graph_.alloc(); } |
| 158 | |
| 159 | static void ReplaceDominatedUsesWith(const MDefinition* orig, MDefinition* dom, |
| 160 | const MBasicBlock* block) { |
| 161 | for (MUseIterator i(orig->usesBegin()); i != orig->usesEnd();) { |
| 162 | MUse* use = *i++; |
| 163 | if (use->consumer() != dom && IsDominatedUse(block, use)) { |
| 164 | use->replaceProducer(dom); |
| 165 | } |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | bool RangeAnalysis::addBetaNodes() { |
| 170 | JitSpew(JitSpew_Range, "Adding beta nodes"); |
| 171 | |
| 172 | for (PostorderIterator i(graph_.poBegin()); i != graph_.poEnd(); i++) { |
| 173 | if (mir->shouldCancel("RangeAnalysis addBetaNodes")) { |
| 174 | return false; |
| 175 | } |
| 176 | |
| 177 | MBasicBlock* block = *i; |
| 178 | JitSpew(JitSpew_Range, "Looking at block %u", block->id()); |
| 179 | |
| 180 | BranchDirection branch_dir; |
| 181 | MTest* test = block->immediateDominatorBranch(&branch_dir); |
| 182 | |
| 183 | if (!test || !test->getOperand(0)->isCompare()) { |
| 184 | continue; |
| 185 | } |
| 186 | |
| 187 | MCompare* compare = test->getOperand(0)->toCompare(); |
| 188 | |
| 189 | if (!compare->isNumericComparison()) { |
| 190 | continue; |
| 191 | } |
| 192 | |
| 193 | // TODO: support unsigned comparisons |
| 194 | if (compare->compareType() == MCompare::Compare_UInt32) { |
| 195 | continue; |
| 196 | } |
| 197 | |
| 198 | // isNumericComparison should return false for (U)IntPtr. |
| 199 | MOZ_ASSERT(compare->compareType() != MCompare::Compare_IntPtr &&do { static_assert( mozilla::detail::AssertionConditionType< decltype(compare->compareType() != MCompare::Compare_IntPtr && compare->compareType() != MCompare::Compare_UIntPtr )>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(compare->compareType() != MCompare::Compare_IntPtr && compare->compareType() != MCompare::Compare_UIntPtr ))), 0))) { do { } while (false); MOZ_ReportAssertionFailure( "compare->compareType() != MCompare::Compare_IntPtr && compare->compareType() != MCompare::Compare_UIntPtr" , "./../../../../js/src/jit/RangeAnalysis.cpp", 200); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "compare->compareType() != MCompare::Compare_IntPtr && compare->compareType() != MCompare::Compare_UIntPtr" ")"); do { MOZ_CrashSequence(__null, 200); __attribute__((nomerge )) ::abort(); } while (false); } } while (false) |
| 200 | compare->compareType() != MCompare::Compare_UIntPtr)do { static_assert( mozilla::detail::AssertionConditionType< decltype(compare->compareType() != MCompare::Compare_IntPtr && compare->compareType() != MCompare::Compare_UIntPtr )>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(compare->compareType() != MCompare::Compare_IntPtr && compare->compareType() != MCompare::Compare_UIntPtr ))), 0))) { do { } while (false); MOZ_ReportAssertionFailure( "compare->compareType() != MCompare::Compare_IntPtr && compare->compareType() != MCompare::Compare_UIntPtr" , "./../../../../js/src/jit/RangeAnalysis.cpp", 200); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "compare->compareType() != MCompare::Compare_IntPtr && compare->compareType() != MCompare::Compare_UIntPtr" ")"); do { MOZ_CrashSequence(__null, 200); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 201 | |
| 202 | MDefinition* left = compare->getOperand(0); |
| 203 | MDefinition* right = compare->getOperand(1); |
| 204 | double bound; |
| 205 | double conservativeLower = NegativeInfinity<double>(); |
| 206 | double conservativeUpper = PositiveInfinity<double>(); |
| 207 | MDefinition* val = nullptr; |
| 208 | |
| 209 | JSOp jsop = compare->jsop(); |
| 210 | |
| 211 | if (branch_dir == FALSE_BRANCH) { |
| 212 | jsop = NegateCompareOp(jsop); |
| 213 | conservativeLower = GenericNaN(); |
| 214 | conservativeUpper = GenericNaN(); |
| 215 | } |
| 216 | |
| 217 | MConstant* leftConst = left->maybeConstantValue(); |
| 218 | MConstant* rightConst = right->maybeConstantValue(); |
| 219 | if (leftConst && leftConst->isTypeRepresentableAsDouble()) { |
| 220 | bound = leftConst->numberToDouble(); |
| 221 | val = right; |
| 222 | jsop = ReverseCompareOp(jsop); |
| 223 | } else if (rightConst && rightConst->isTypeRepresentableAsDouble()) { |
| 224 | bound = rightConst->numberToDouble(); |
| 225 | val = left; |
| 226 | } else if (left->type() == MIRType::Int32 && |
| 227 | right->type() == MIRType::Int32) { |
| 228 | MDefinition* smaller = nullptr; |
| 229 | MDefinition* greater = nullptr; |
| 230 | if (jsop == JSOp::Lt) { |
| 231 | smaller = left; |
| 232 | greater = right; |
| 233 | } else if (jsop == JSOp::Gt) { |
| 234 | smaller = right; |
| 235 | greater = left; |
| 236 | } |
| 237 | if (smaller && greater) { |
| 238 | if (!alloc().ensureBallast()) { |
| 239 | return false; |
| 240 | } |
| 241 | |
| 242 | MBeta* beta; |
| 243 | beta = MBeta::New( |
| 244 | alloc(), smaller, |
| 245 | Range::NewInt32Range(alloc(), JSVAL_INT_MIN((int32_t)0x80000000), JSVAL_INT_MAX((int32_t)0x7fffffff) - 1)); |
| 246 | block->insertBefore(*block->begin(), beta); |
| 247 | ReplaceDominatedUsesWith(smaller, beta, block); |
| 248 | JitSpew(JitSpew_Range, " Adding beta node for smaller %u", |
| 249 | smaller->id()); |
| 250 | beta = MBeta::New( |
| 251 | alloc(), greater, |
| 252 | Range::NewInt32Range(alloc(), JSVAL_INT_MIN((int32_t)0x80000000) + 1, JSVAL_INT_MAX((int32_t)0x7fffffff))); |
| 253 | block->insertBefore(*block->begin(), beta); |
| 254 | ReplaceDominatedUsesWith(greater, beta, block); |
| 255 | JitSpew(JitSpew_Range, " Adding beta node for greater %u", |
| 256 | greater->id()); |
| 257 | } |
| 258 | continue; |
| 259 | } else { |
| 260 | continue; |
| 261 | } |
| 262 | |
| 263 | // At this point, one of the operands if the compare is a constant, and |
| 264 | // val is the other operand. |
| 265 | MOZ_ASSERT(val)do { static_assert( mozilla::detail::AssertionConditionType< decltype(val)>::isValid, "invalid assertion condition"); if ((__builtin_expect(!!(!(!!(val))), 0))) { do { } while (false ); MOZ_ReportAssertionFailure("val", "./../../../../js/src/jit/RangeAnalysis.cpp" , 265); AnnotateMozCrashReason("MOZ_ASSERT" "(" "val" ")"); do { MOZ_CrashSequence(__null, 265); __attribute__((nomerge)) :: abort(); } while (false); } } while (false); |
| 266 | |
| 267 | Range comp; |
| 268 | switch (jsop) { |
| 269 | case JSOp::Le: |
| 270 | comp.setDouble(conservativeLower, bound); |
| 271 | break; |
| 272 | case JSOp::Lt: |
| 273 | // For integers, if x < c, the upper bound of x is c-1. |
| 274 | if (val->type() == MIRType::Int32) { |
| 275 | int32_t intbound; |
| 276 | if (NumberEqualsInt32(bound, &intbound) && |
| 277 | mozilla::SafeSub(intbound, 1, &intbound)) { |
| 278 | bound = intbound; |
| 279 | } |
| 280 | } |
| 281 | comp.setDouble(conservativeLower, bound); |
| 282 | |
| 283 | // Negative zero is not less than zero. |
| 284 | if (bound == 0) { |
| 285 | comp.refineToExcludeNegativeZero(); |
| 286 | } |
| 287 | break; |
| 288 | case JSOp::Ge: |
| 289 | comp.setDouble(bound, conservativeUpper); |
| 290 | break; |
| 291 | case JSOp::Gt: |
| 292 | // For integers, if x > c, the lower bound of x is c+1. |
| 293 | if (val->type() == MIRType::Int32) { |
| 294 | int32_t intbound; |
| 295 | if (NumberEqualsInt32(bound, &intbound) && |
| 296 | mozilla::SafeAdd(intbound, 1, &intbound)) { |
| 297 | bound = intbound; |
| 298 | } |
| 299 | } |
| 300 | comp.setDouble(bound, conservativeUpper); |
| 301 | |
| 302 | // Negative zero is not greater than zero. |
| 303 | if (bound == 0) { |
| 304 | comp.refineToExcludeNegativeZero(); |
| 305 | } |
| 306 | break; |
| 307 | case JSOp::StrictEq: |
| 308 | case JSOp::Eq: |
| 309 | comp.setDouble(bound, bound); |
| 310 | break; |
| 311 | case JSOp::StrictNe: |
| 312 | case JSOp::Ne: |
| 313 | // Negative zero is not not-equal to zero. |
| 314 | if (bound == 0) { |
| 315 | comp.refineToExcludeNegativeZero(); |
| 316 | break; |
| 317 | } |
| 318 | continue; // well, we could have |
| 319 | // [-\inf, bound-1] U [bound+1, \inf] but we only use |
| 320 | // contiguous ranges. |
| 321 | default: |
| 322 | continue; |
| 323 | } |
| 324 | |
| 325 | if (JitSpewEnabled(JitSpew_Range)) { |
| 326 | AutoJitSpewMessage msg( |
| 327 | JitSpew_Range, " Adding beta node for %u with range ", val->id()); |
| 328 | comp.dump(msg.printer()); |
| 329 | } |
| 330 | |
| 331 | if (!alloc().ensureBallast()) { |
| 332 | return false; |
| 333 | } |
| 334 | |
| 335 | MBeta* beta = MBeta::New(alloc(), val, new (alloc()) Range(comp)); |
| 336 | block->insertBefore(*block->begin(), beta); |
| 337 | ReplaceDominatedUsesWith(val, beta, block); |
| 338 | } |
| 339 | |
| 340 | return true; |
| 341 | } |
| 342 | |
| 343 | bool RangeAnalysis::removeBetaNodes() { |
| 344 | JitSpew(JitSpew_Range, "Removing beta nodes"); |
| 345 | |
| 346 | for (PostorderIterator i(graph_.poBegin()); i != graph_.poEnd(); i++) { |
| 347 | MBasicBlock* block = *i; |
| 348 | for (MDefinitionIterator iter(*i); iter;) { |
| 349 | MDefinition* def = *iter++; |
| 350 | if (def->isBeta()) { |
| 351 | auto* beta = def->toBeta(); |
| 352 | MDefinition* op = beta->input(); |
| 353 | JitSpew(JitSpew_Range, " Removing beta node %u for %u", beta->id(), |
| 354 | op->id()); |
| 355 | beta->justReplaceAllUsesWith(op); |
| 356 | block->discard(beta); |
| 357 | } else { |
| 358 | // We only place Beta nodes at the beginning of basic |
| 359 | // blocks, so if we see something else, we can move on |
| 360 | // to the next block. |
| 361 | break; |
| 362 | } |
| 363 | } |
| 364 | } |
| 365 | return true; |
| 366 | } |
| 367 | |
| 368 | void SymbolicBound::dump(GenericPrinter& out) const { |
| 369 | if (loop) { |
| 370 | out.printf("[loop] "); |
| 371 | } |
| 372 | sum.dump(out); |
| 373 | } |
| 374 | |
| 375 | void SymbolicBound::dump() const { |
| 376 | Fprinter out(stderrstderr); |
| 377 | dump(out); |
| 378 | out.printf("\n"); |
| 379 | out.finish(); |
| 380 | } |
| 381 | |
| 382 | // Test whether the given range's exponent tells us anything that its lower |
| 383 | // and upper bound values don't. |
| 384 | static bool IsExponentInteresting(const Range* r) { |
| 385 | // If it lacks either a lower or upper bound, the exponent is interesting. |
| 386 | if (!r->hasInt32Bounds()) { |
| 387 | return true; |
| 388 | } |
| 389 | |
| 390 | // Otherwise if there's no fractional part, the lower and upper bounds, |
| 391 | // which are integers, are perfectly precise. |
| 392 | if (!r->canHaveFractionalPart()) { |
| 393 | return false; |
| 394 | } |
| 395 | |
| 396 | // Otherwise, if the bounds are conservatively rounded across a power-of-two |
| 397 | // boundary, the exponent may imply a tighter range. |
| 398 | return FloorLog2(std::max(Abs(r->lower()), Abs(r->upper()))) > r->exponent(); |
| 399 | } |
| 400 | |
| 401 | void Range::dump(GenericPrinter& out) const { |
| 402 | assertInvariants(); |
| 403 | |
| 404 | // Floating-point or Integer subset. |
| 405 | if (canHaveFractionalPart_) { |
| 406 | out.printf("F"); |
| 407 | } else { |
| 408 | out.printf("I"); |
| 409 | } |
| 410 | |
| 411 | out.printf("["); |
| 412 | |
| 413 | if (!hasInt32LowerBound_) { |
| 414 | out.printf("?"); |
| 415 | } else { |
| 416 | out.printf("%d", lower_); |
| 417 | } |
| 418 | if (symbolicLower_) { |
| 419 | out.printf(" {"); |
| 420 | symbolicLower_->dump(out); |
| 421 | out.printf("}"); |
| 422 | } |
| 423 | |
| 424 | out.printf(", "); |
| 425 | |
| 426 | if (!hasInt32UpperBound_) { |
| 427 | out.printf("?"); |
| 428 | } else { |
| 429 | out.printf("%d", upper_); |
| 430 | } |
| 431 | if (symbolicUpper_) { |
| 432 | out.printf(" {"); |
| 433 | symbolicUpper_->dump(out); |
| 434 | out.printf("}"); |
| 435 | } |
| 436 | |
| 437 | out.printf("]"); |
| 438 | |
| 439 | bool includesNaN = max_exponent_ == IncludesInfinityAndNaN; |
| 440 | bool includesNegativeInfinity = |
| 441 | max_exponent_ >= IncludesInfinity && !hasInt32LowerBound_; |
| 442 | bool includesPositiveInfinity = |
| 443 | max_exponent_ >= IncludesInfinity && !hasInt32UpperBound_; |
| 444 | bool includesNegativeZero = canBeNegativeZero_; |
| 445 | |
| 446 | if (includesNaN || includesNegativeInfinity || includesPositiveInfinity || |
| 447 | includesNegativeZero) { |
| 448 | out.printf(" ("); |
| 449 | bool first = true; |
| 450 | if (includesNaN) { |
| 451 | if (first) { |
| 452 | first = false; |
| 453 | } else { |
| 454 | out.printf(" "); |
| 455 | } |
| 456 | out.printf("U NaN"); |
| 457 | } |
| 458 | if (includesNegativeInfinity) { |
| 459 | if (first) { |
| 460 | first = false; |
| 461 | } else { |
| 462 | out.printf(" "); |
| 463 | } |
| 464 | out.printf("U -Infinity"); |
| 465 | } |
| 466 | if (includesPositiveInfinity) { |
| 467 | if (first) { |
| 468 | first = false; |
| 469 | } else { |
| 470 | out.printf(" "); |
| 471 | } |
| 472 | out.printf("U Infinity"); |
| 473 | } |
| 474 | if (includesNegativeZero) { |
| 475 | if (first) { |
| 476 | first = false; |
Value stored to 'first' is never read | |
| 477 | } else { |
| 478 | out.printf(" "); |
| 479 | } |
| 480 | out.printf("U -0"); |
| 481 | } |
| 482 | out.printf(")"); |
| 483 | } |
| 484 | if (max_exponent_ < IncludesInfinity && IsExponentInteresting(this)) { |
| 485 | out.printf(" (< pow(2, %d+1))", max_exponent_); |
| 486 | } |
| 487 | } |
| 488 | |
| 489 | void Range::dump() const { |
| 490 | Fprinter out(stderrstderr); |
| 491 | dump(out); |
| 492 | out.printf("\n"); |
| 493 | out.finish(); |
| 494 | } |
| 495 | |
| 496 | Range* Range::intersect(TempAllocator& alloc, const Range* lhs, |
| 497 | const Range* rhs, bool* emptyRange) { |
| 498 | *emptyRange = false; |
| 499 | |
| 500 | if (!lhs && !rhs) { |
| 501 | return nullptr; |
| 502 | } |
| 503 | |
| 504 | if (!lhs) { |
| 505 | return new (alloc) Range(*rhs); |
| 506 | } |
| 507 | if (!rhs) { |
| 508 | return new (alloc) Range(*lhs); |
| 509 | } |
| 510 | |
| 511 | int32_t newLower = std::max(lhs->lower_, rhs->lower_); |
| 512 | int32_t newUpper = std::min(lhs->upper_, rhs->upper_); |
| 513 | |
| 514 | // If upper < lower, then we have conflicting constraints. Consider: |
| 515 | // |
| 516 | // if (x < 0) { |
| 517 | // if (x > 0) { |
| 518 | // [Some code.] |
| 519 | // } |
| 520 | // } |
| 521 | // |
| 522 | // In this case, the block is unreachable. |
| 523 | if (newUpper < newLower) { |
| 524 | // If both ranges can be NaN, the result can still be NaN. |
| 525 | if (!lhs->canBeNaN() || !rhs->canBeNaN()) { |
| 526 | *emptyRange = true; |
| 527 | } |
| 528 | return nullptr; |
| 529 | } |
| 530 | |
| 531 | bool newHasInt32LowerBound = |
| 532 | lhs->hasInt32LowerBound_ || rhs->hasInt32LowerBound_; |
| 533 | bool newHasInt32UpperBound = |
| 534 | lhs->hasInt32UpperBound_ || rhs->hasInt32UpperBound_; |
| 535 | |
| 536 | FractionalPartFlag newCanHaveFractionalPart = FractionalPartFlag( |
| 537 | lhs->canHaveFractionalPart_ && rhs->canHaveFractionalPart_); |
| 538 | |
| 539 | // As 0.0 == -0.0, the intersection should include negative zero if any of the |
| 540 | // operands can be negative zero. |
| 541 | NegativeZeroFlag newMayIncludeNegativeZero = |
| 542 | NegativeZeroFlag((lhs->canBeNegativeZero_ && rhs->canBeZero()) || |
| 543 | (rhs->canBeNegativeZero_ && lhs->canBeZero())); |
| 544 | |
| 545 | uint16_t newExponent = std::min(lhs->max_exponent_, rhs->max_exponent_); |
| 546 | |
| 547 | // NaN is a special value which is neither greater than infinity or less than |
| 548 | // negative infinity. When we intersect two ranges like [?, 0] and [0, ?], we |
| 549 | // can end up thinking we have both a lower and upper bound, even though NaN |
| 550 | // is still possible. In this case, just be conservative, since any case where |
| 551 | // we can have NaN is not especially interesting. |
| 552 | if (newHasInt32LowerBound && newHasInt32UpperBound && |
| 553 | newExponent == IncludesInfinityAndNaN) { |
| 554 | return nullptr; |
| 555 | } |
| 556 | |
| 557 | // If one of the ranges has a fractional part and the other doesn't, it's |
| 558 | // possible that we will have computed a newExponent that's more precise |
| 559 | // than our newLower and newUpper. This is unusual, so we handle it here |
| 560 | // instead of in optimize(). |
| 561 | // |
| 562 | // For example, consider the range F[0,1.5]. Range analysis represents the |
| 563 | // lower and upper bound as integers, so we'd actually have |
| 564 | // F[0,2] (< pow(2, 0+1)). In this case, the exponent gives us a slightly |
| 565 | // more precise upper bound than the integer upper bound. |
| 566 | // |
| 567 | // When intersecting such a range with an integer range, the fractional part |
| 568 | // of the range is dropped. The max exponent of 0 remains valid, so the |
| 569 | // upper bound needs to be adjusted to 1. |
| 570 | // |
| 571 | // When intersecting F[0,2] (< pow(2, 0+1)) with a range like F[2,4], |
| 572 | // the naive intersection is I[2,2], but since the max exponent tells us |
| 573 | // that the value is always less than 2, the intersection is actually empty. |
| 574 | if (lhs->canHaveFractionalPart() != rhs->canHaveFractionalPart() || |
| 575 | (lhs->canHaveFractionalPart() && newHasInt32LowerBound && |
| 576 | newHasInt32UpperBound && newLower == newUpper)) { |
| 577 | refineInt32BoundsByExponent(newExponent, &newLower, &newHasInt32LowerBound, |
| 578 | &newUpper, &newHasInt32UpperBound); |
| 579 | |
| 580 | // If we're intersecting two ranges that don't overlap, this could also |
| 581 | // push the bounds past each other, since the actual intersection is |
| 582 | // the empty set. |
| 583 | if (newLower > newUpper) { |
| 584 | *emptyRange = true; |
| 585 | return nullptr; |
| 586 | } |
| 587 | } |
| 588 | |
| 589 | return new (alloc) |
| 590 | Range(newLower, newHasInt32LowerBound, newUpper, newHasInt32UpperBound, |
| 591 | newCanHaveFractionalPart, newMayIncludeNegativeZero, newExponent); |
| 592 | } |
| 593 | |
| 594 | void Range::unionWith(const Range* other) { |
| 595 | int32_t newLower = std::min(lower_, other->lower_); |
| 596 | int32_t newUpper = std::max(upper_, other->upper_); |
| 597 | |
| 598 | bool newHasInt32LowerBound = |
| 599 | hasInt32LowerBound_ && other->hasInt32LowerBound_; |
| 600 | bool newHasInt32UpperBound = |
| 601 | hasInt32UpperBound_ && other->hasInt32UpperBound_; |
| 602 | |
| 603 | FractionalPartFlag newCanHaveFractionalPart = FractionalPartFlag( |
| 604 | canHaveFractionalPart_ || other->canHaveFractionalPart_); |
| 605 | NegativeZeroFlag newMayIncludeNegativeZero = |
| 606 | NegativeZeroFlag(canBeNegativeZero_ || other->canBeNegativeZero_); |
| 607 | |
| 608 | uint16_t newExponent = std::max(max_exponent_, other->max_exponent_); |
| 609 | |
| 610 | rawInitialize(newLower, newHasInt32LowerBound, newUpper, |
| 611 | newHasInt32UpperBound, newCanHaveFractionalPart, |
| 612 | newMayIncludeNegativeZero, newExponent); |
| 613 | } |
| 614 | |
| 615 | Range::Range(const MDefinition* def) |
| 616 | : symbolicLower_(nullptr), symbolicUpper_(nullptr) { |
| 617 | if (const Range* other = def->range()) { |
| 618 | // The instruction has range information; use it. |
| 619 | *this = *other; |
| 620 | |
| 621 | // Simulate the effect of converting the value to its type. |
| 622 | // Note: we cannot clamp here, since ranges aren't allowed to shrink |
| 623 | // and truncation can increase range again. So doing wrapAround to |
| 624 | // mimick a possible truncation. |
| 625 | switch (def->type()) { |
| 626 | case MIRType::Int32: |
| 627 | // MToNumberInt32 cannot truncate. So we can safely clamp. |
| 628 | if (def->isToNumberInt32()) { |
| 629 | clampToInt32(); |
| 630 | } else { |
| 631 | wrapAroundToInt32(); |
| 632 | } |
| 633 | break; |
| 634 | case MIRType::Boolean: |
| 635 | wrapAroundToBoolean(); |
| 636 | break; |
| 637 | case MIRType::None: |
| 638 | MOZ_CRASH("Asking for the range of an instruction with no value")do { do { } while (false); MOZ_ReportCrash("" "Asking for the range of an instruction with no value" , "./../../../../js/src/jit/RangeAnalysis.cpp", 638); AnnotateMozCrashReason ("MOZ_CRASH(" "Asking for the range of an instruction with no value" ")"); do { MOZ_CrashSequence(__null, 638); __attribute__((nomerge )) ::abort(); } while (false); } while (false); |
| 639 | default: |
| 640 | break; |
| 641 | } |
| 642 | } else { |
| 643 | // Otherwise just use type information. We can trust the type here |
| 644 | // because we don't care what value the instruction actually produces, |
| 645 | // but what value we might get after we get past the bailouts. |
| 646 | switch (def->type()) { |
| 647 | case MIRType::Int32: |
| 648 | setInt32(JSVAL_INT_MIN((int32_t)0x80000000), JSVAL_INT_MAX((int32_t)0x7fffffff)); |
| 649 | break; |
| 650 | case MIRType::Boolean: |
| 651 | setInt32(0, 1); |
| 652 | break; |
| 653 | case MIRType::None: |
| 654 | MOZ_CRASH("Asking for the range of an instruction with no value")do { do { } while (false); MOZ_ReportCrash("" "Asking for the range of an instruction with no value" , "./../../../../js/src/jit/RangeAnalysis.cpp", 654); AnnotateMozCrashReason ("MOZ_CRASH(" "Asking for the range of an instruction with no value" ")"); do { MOZ_CrashSequence(__null, 654); __attribute__((nomerge )) ::abort(); } while (false); } while (false); |
| 655 | default: |
| 656 | setUnknown(); |
| 657 | break; |
| 658 | } |
| 659 | } |
| 660 | |
| 661 | // As a special case, MUrsh is permitted to claim a result type of |
| 662 | // MIRType::Int32 while actually returning values in [0,UINT32_MAX] without |
| 663 | // bailouts. If range analysis hasn't ruled out values in |
| 664 | // (INT32_MAX,UINT32_MAX], set the range to be conservatively correct for |
| 665 | // use as either a uint32 or an int32. |
| 666 | if (!hasInt32UpperBound() && def->isUrsh() && |
| 667 | def->toUrsh()->bailoutsDisabled() && def->type() != MIRType::Int64) { |
| 668 | lower_ = INT32_MIN(-2147483647-1); |
| 669 | } |
| 670 | |
| 671 | assertInvariants(); |
| 672 | } |
| 673 | |
| 674 | static uint16_t ExponentImpliedByDouble(double d) { |
| 675 | // Handle the special values. |
| 676 | if (std::isnan(d)) { |
| 677 | return Range::IncludesInfinityAndNaN; |
| 678 | } |
| 679 | if (std::isinf(d)) { |
| 680 | return Range::IncludesInfinity; |
| 681 | } |
| 682 | |
| 683 | // Otherwise take the exponent part and clamp it at zero, since the Range |
| 684 | // class doesn't track fractional ranges. |
| 685 | return uint16_t(std::max(int_fast16_t(0), ExponentComponent(d))); |
| 686 | } |
| 687 | |
| 688 | void Range::setDouble(double l, double h) { |
| 689 | MOZ_ASSERT(!(l > h))do { static_assert( mozilla::detail::AssertionConditionType< decltype(!(l > h))>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(!(l > h)))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("!(l > h)", "./../../../../js/src/jit/RangeAnalysis.cpp" , 689); AnnotateMozCrashReason("MOZ_ASSERT" "(" "!(l > h)" ")"); do { MOZ_CrashSequence(__null, 689); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 690 | |
| 691 | // Infer lower_, upper_, hasInt32LowerBound_, and hasInt32UpperBound_. |
| 692 | if (l >= INT32_MIN(-2147483647-1) && l <= INT32_MAX(2147483647)) { |
| 693 | lower_ = int32_t(::floor(l)); |
| 694 | hasInt32LowerBound_ = true; |
| 695 | } else if (l >= INT32_MAX(2147483647)) { |
| 696 | lower_ = INT32_MAX(2147483647); |
| 697 | hasInt32LowerBound_ = true; |
| 698 | } else { |
| 699 | lower_ = INT32_MIN(-2147483647-1); |
| 700 | hasInt32LowerBound_ = false; |
| 701 | } |
| 702 | if (h >= INT32_MIN(-2147483647-1) && h <= INT32_MAX(2147483647)) { |
| 703 | upper_ = int32_t(::ceil(h)); |
| 704 | hasInt32UpperBound_ = true; |
| 705 | } else if (h <= INT32_MIN(-2147483647-1)) { |
| 706 | upper_ = INT32_MIN(-2147483647-1); |
| 707 | hasInt32UpperBound_ = true; |
| 708 | } else { |
| 709 | upper_ = INT32_MAX(2147483647); |
| 710 | hasInt32UpperBound_ = false; |
| 711 | } |
| 712 | |
| 713 | // Infer max_exponent_. |
| 714 | uint16_t lExp = ExponentImpliedByDouble(l); |
| 715 | uint16_t hExp = ExponentImpliedByDouble(h); |
| 716 | max_exponent_ = std::max(lExp, hExp); |
| 717 | |
| 718 | canHaveFractionalPart_ = ExcludesFractionalParts; |
| 719 | canBeNegativeZero_ = ExcludesNegativeZero; |
| 720 | |
| 721 | // If denormals are disabled, any denormal value will be immediately flushed |
| 722 | // to 0, so any bit pattern in the denormal range compares equal to zero. |
| 723 | // |
| 724 | // Check whether the range [l .. h] can cross any of these zeros. We have to |
| 725 | // be conservative as the main thread might not interpret floating point |
| 726 | // values the same way as the compiler thread. |
| 727 | // |
| 728 | // This Range may describe a Float32 value, whose denormal range begins at |
| 729 | // the smallest normal binary32 (2**-126) rather than the smallest normal |
| 730 | // binary64 (2**-1022). Use the (wider) binary32 threshold so we stay |
| 731 | // conservative for both float32 and double values. |
| 732 | const double doubleMin = double(mozilla::BitwiseCast<float>( |
| 733 | mozilla::SpecificFloatingPointBits<float, 0, 1, 0>::value)); |
| 734 | bool includesNegative = std::isnan(l) || l < doubleMin; |
| 735 | bool includesPositive = std::isnan(h) || h > -doubleMin; |
| 736 | bool crossesZero = includesNegative && includesPositive; |
| 737 | |
| 738 | // Infer the canHaveFractionalPart_ setting. We can have a |
| 739 | // fractional part if the range crosses through the neighborhood of zero. We |
| 740 | // won't have a fractional value if the value is always beyond the point at |
| 741 | // which double precision can't represent fractional values. |
| 742 | uint16_t minExp = std::min(lExp, hExp); |
| 743 | if (crossesZero || minExp < MaxTruncatableExponent) { |
| 744 | canHaveFractionalPart_ = IncludesFractionalParts; |
| 745 | } |
| 746 | |
| 747 | // Infer a conservative value for canBeNegativeZero_ setting. We can have a |
| 748 | // negative zero value if the range crosses through the neighborhood of zero |
| 749 | // and the lower bound can have a sign bit. |
| 750 | if (crossesZero && (std::isnan(l) || mozilla::IsNegative(l))) { |
| 751 | canBeNegativeZero_ = IncludesNegativeZero; |
| 752 | } |
| 753 | |
| 754 | optimize(); |
| 755 | } |
| 756 | |
| 757 | void Range::setDoubleSingleton(double d) { |
| 758 | setDouble(d, d); |
| 759 | assertInvariants(); |
| 760 | } |
| 761 | |
| 762 | static inline bool MissingAnyInt32Bounds(const Range* lhs, const Range* rhs) { |
| 763 | return !lhs->hasInt32Bounds() || !rhs->hasInt32Bounds(); |
| 764 | } |
| 765 | |
| 766 | Range* Range::add(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 767 | int64_t l = (int64_t)lhs->lower_ + (int64_t)rhs->lower_; |
| 768 | if (!lhs->hasInt32LowerBound() || !rhs->hasInt32LowerBound()) { |
| 769 | l = NoInt32LowerBound; |
| 770 | } |
| 771 | |
| 772 | int64_t h = (int64_t)lhs->upper_ + (int64_t)rhs->upper_; |
| 773 | if (!lhs->hasInt32UpperBound() || !rhs->hasInt32UpperBound()) { |
| 774 | h = NoInt32UpperBound; |
| 775 | } |
| 776 | |
| 777 | // The exponent is at most one greater than the greater of the operands' |
| 778 | // exponents, except for NaN and infinity cases. |
| 779 | uint16_t e = std::max(lhs->max_exponent_, rhs->max_exponent_); |
| 780 | if (e <= Range::MaxFiniteExponent) { |
| 781 | ++e; |
| 782 | } |
| 783 | |
| 784 | // Infinity + -Infinity is NaN. |
| 785 | if (lhs->canBeInfiniteOrNaN() && rhs->canBeInfiniteOrNaN()) { |
| 786 | e = Range::IncludesInfinityAndNaN; |
| 787 | } |
| 788 | |
| 789 | FractionalPartFlag canHaveFractionalPart = FractionalPartFlag( |
| 790 | lhs->canHaveFractionalPart() || rhs->canHaveFractionalPart()); |
| 791 | |
| 792 | // Handle the case where -0 + -0 == -0. |
| 793 | NegativeZeroFlag canBeNegativeZero = |
| 794 | NegativeZeroFlag(lhs->canBeNegativeZero() && rhs->canBeNegativeZero()); |
| 795 | |
| 796 | // Except for operands which have a fractional part, in the corner case where |
| 797 | // denormals are disabled on the execution thread but not on the compiling |
| 798 | // thread. |
| 799 | // |
| 800 | // Example -0 + -1.11e-308 == -0 (denormals disabled) |
| 801 | if (l <= 0 && h >= 0 && canHaveFractionalPart) { |
| 802 | canBeNegativeZero = IncludesNegativeZero; |
| 803 | } |
| 804 | |
| 805 | return new (alloc) Range(l, h, canHaveFractionalPart, canBeNegativeZero, e); |
| 806 | } |
| 807 | |
| 808 | Range* Range::sub(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 809 | int64_t l = (int64_t)lhs->lower_ - (int64_t)rhs->upper_; |
| 810 | if (!lhs->hasInt32LowerBound() || !rhs->hasInt32UpperBound()) { |
| 811 | l = NoInt32LowerBound; |
| 812 | } |
| 813 | |
| 814 | int64_t h = (int64_t)lhs->upper_ - (int64_t)rhs->lower_; |
| 815 | if (!lhs->hasInt32UpperBound() || !rhs->hasInt32LowerBound()) { |
| 816 | h = NoInt32UpperBound; |
| 817 | } |
| 818 | |
| 819 | // The exponent is at most one greater than the greater of the operands' |
| 820 | // exponents, except for NaN and infinity cases. |
| 821 | uint16_t e = std::max(lhs->max_exponent_, rhs->max_exponent_); |
| 822 | if (e <= Range::MaxFiniteExponent) { |
| 823 | ++e; |
| 824 | } |
| 825 | |
| 826 | // Infinity - Infinity is NaN. |
| 827 | if (lhs->canBeInfiniteOrNaN() && rhs->canBeInfiniteOrNaN()) { |
| 828 | e = Range::IncludesInfinityAndNaN; |
| 829 | } |
| 830 | |
| 831 | FractionalPartFlag canHaveFractionalPart = FractionalPartFlag( |
| 832 | lhs->canHaveFractionalPart() || rhs->canHaveFractionalPart()); |
| 833 | |
| 834 | // Handle the case where -0 - 0 == -0. |
| 835 | NegativeZeroFlag canBeNegativeZero = |
| 836 | NegativeZeroFlag(lhs->canBeNegativeZero() && rhs->canBeZero()); |
| 837 | |
| 838 | // Except for operands which have a fractional part, in the corner case where |
| 839 | // denormals are disabled on the execution thread but not on the compiling |
| 840 | // thread. |
| 841 | if (l <= 0 && h >= 0 && canHaveFractionalPart) { |
| 842 | canBeNegativeZero = IncludesNegativeZero; |
| 843 | } |
| 844 | |
| 845 | return new (alloc) Range(l, h, canHaveFractionalPart, canBeNegativeZero, e); |
| 846 | } |
| 847 | |
| 848 | Range* Range::and_(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 849 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 849); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 849); __attribute__((nomerge)) ::abort(); } while (false ); } } while (false); |
| 850 | MOZ_ASSERT(rhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(rhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(rhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("rhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 850); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "rhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 850); __attribute__((nomerge)) ::abort(); } while (false ); } } while (false); |
| 851 | |
| 852 | // If both numbers can be negative, result can be negative in the whole range |
| 853 | if (lhs->lower() < 0 && rhs->lower() < 0) { |
| 854 | return Range::NewInt32Range(alloc, INT32_MIN(-2147483647-1), |
| 855 | std::max(lhs->upper(), rhs->upper())); |
| 856 | } |
| 857 | |
| 858 | // Only one of both numbers can be negative. |
| 859 | // - result can't be negative |
| 860 | // - Upper bound is minimum of both upper range, |
| 861 | int32_t lower = 0; |
| 862 | int32_t upper = std::min(lhs->upper(), rhs->upper()); |
| 863 | |
| 864 | // EXCEPT when upper bound of non negative number is max value, |
| 865 | // because negative value can return the whole max value. |
| 866 | // -1 & 5 = 5 |
| 867 | if (lhs->lower() < 0) { |
| 868 | upper = rhs->upper(); |
| 869 | } |
| 870 | if (rhs->lower() < 0) { |
| 871 | upper = lhs->upper(); |
| 872 | } |
| 873 | |
| 874 | return Range::NewInt32Range(alloc, lower, upper); |
| 875 | } |
| 876 | |
| 877 | Range* Range::or_(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 878 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 878); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 878); __attribute__((nomerge)) ::abort(); } while (false ); } } while (false); |
| 879 | MOZ_ASSERT(rhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(rhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(rhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("rhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 879); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "rhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 879); __attribute__((nomerge)) ::abort(); } while (false ); } } while (false); |
| 880 | // When one operand is always 0 or always -1, it's a special case where we |
| 881 | // can compute a fully precise result. Handling these up front also protects |
| 882 | // the code below from shifting an int32_t by 32. |
| 883 | if (lhs->lower() == lhs->upper()) { |
| 884 | if (lhs->lower() == 0) { |
| 885 | return new (alloc) Range(*rhs); |
| 886 | } |
| 887 | if (lhs->lower() == -1) { |
| 888 | return new (alloc) Range(*lhs); |
| 889 | } |
| 890 | } |
| 891 | if (rhs->lower() == rhs->upper()) { |
| 892 | if (rhs->lower() == 0) { |
| 893 | return new (alloc) Range(*lhs); |
| 894 | } |
| 895 | if (rhs->lower() == -1) { |
| 896 | return new (alloc) Range(*rhs); |
| 897 | } |
| 898 | } |
| 899 | |
| 900 | // The code below uses std::countl_zero, which returns 32 if its operand is 0. |
| 901 | // We rely on the code above to protect it. |
| 902 | MOZ_ASSERT_IF(lhs->lower() >= 0, lhs->upper() != 0)do { if (lhs->lower() >= 0) { do { static_assert( mozilla ::detail::AssertionConditionType<decltype(lhs->upper() != 0)>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(lhs->upper() != 0))), 0))) { do { } while (false) ; MOZ_ReportAssertionFailure("lhs->upper() != 0", "./../../../../js/src/jit/RangeAnalysis.cpp" , 902); AnnotateMozCrashReason("MOZ_ASSERT" "(" "lhs->upper() != 0" ")"); do { MOZ_CrashSequence(__null, 902); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); } } while ( false); |
| 903 | MOZ_ASSERT_IF(rhs->lower() >= 0, rhs->upper() != 0)do { if (rhs->lower() >= 0) { do { static_assert( mozilla ::detail::AssertionConditionType<decltype(rhs->upper() != 0)>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(rhs->upper() != 0))), 0))) { do { } while (false) ; MOZ_ReportAssertionFailure("rhs->upper() != 0", "./../../../../js/src/jit/RangeAnalysis.cpp" , 903); AnnotateMozCrashReason("MOZ_ASSERT" "(" "rhs->upper() != 0" ")"); do { MOZ_CrashSequence(__null, 903); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); } } while ( false); |
| 904 | MOZ_ASSERT_IF(lhs->upper() < 0, lhs->lower() != -1)do { if (lhs->upper() < 0) { do { static_assert( mozilla ::detail::AssertionConditionType<decltype(lhs->lower() != -1)>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(lhs->lower() != -1))), 0))) { do { } while (false ); MOZ_ReportAssertionFailure("lhs->lower() != -1", "./../../../../js/src/jit/RangeAnalysis.cpp" , 904); AnnotateMozCrashReason("MOZ_ASSERT" "(" "lhs->lower() != -1" ")"); do { MOZ_CrashSequence(__null, 904); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); } } while ( false); |
| 905 | MOZ_ASSERT_IF(rhs->upper() < 0, rhs->lower() != -1)do { if (rhs->upper() < 0) { do { static_assert( mozilla ::detail::AssertionConditionType<decltype(rhs->lower() != -1)>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(rhs->lower() != -1))), 0))) { do { } while (false ); MOZ_ReportAssertionFailure("rhs->lower() != -1", "./../../../../js/src/jit/RangeAnalysis.cpp" , 905); AnnotateMozCrashReason("MOZ_ASSERT" "(" "rhs->lower() != -1" ")"); do { MOZ_CrashSequence(__null, 905); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); } } while ( false); |
| 906 | |
| 907 | int32_t lower = INT32_MIN(-2147483647-1); |
| 908 | int32_t upper = INT32_MAX(2147483647); |
| 909 | |
| 910 | if (lhs->lower() >= 0 && rhs->lower() >= 0) { |
| 911 | // Both operands are non-negative, so the result won't be less than either. |
| 912 | lower = std::max(lhs->lower(), rhs->lower()); |
| 913 | // The result will have leading zeros where both operands have leading |
| 914 | // zeros. std::countl_zero of a non-negative int32 will at least be 1 to |
| 915 | // account for the bit of sign. |
| 916 | upper = int32_t(UINT32_MAX(4294967295U) >> |
| 917 | std::min(std::countl_zero(uint32_t(lhs->upper())), |
| 918 | std::countl_zero(uint32_t(rhs->upper())))); |
| 919 | } else { |
| 920 | // The result will have leading ones where either operand has leading ones. |
| 921 | if (lhs->upper() < 0) { |
| 922 | unsigned leadingOnes = std::countl_one(uint32_t(lhs->lower())); |
| 923 | lower = std::max(lower, ~int32_t(UINT32_MAX(4294967295U) >> leadingOnes)); |
| 924 | upper = -1; |
| 925 | } |
| 926 | if (rhs->upper() < 0) { |
| 927 | unsigned leadingOnes = std::countl_one(uint32_t(rhs->lower())); |
| 928 | lower = std::max(lower, ~int32_t(UINT32_MAX(4294967295U) >> leadingOnes)); |
| 929 | upper = -1; |
| 930 | } |
| 931 | } |
| 932 | |
| 933 | return Range::NewInt32Range(alloc, lower, upper); |
| 934 | } |
| 935 | |
| 936 | Range* Range::xor_(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 937 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 937); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 937); __attribute__((nomerge)) ::abort(); } while (false ); } } while (false); |
| 938 | MOZ_ASSERT(rhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(rhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(rhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("rhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 938); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "rhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 938); __attribute__((nomerge)) ::abort(); } while (false ); } } while (false); |
| 939 | int32_t lhsLower = lhs->lower(); |
| 940 | int32_t lhsUpper = lhs->upper(); |
| 941 | int32_t rhsLower = rhs->lower(); |
| 942 | int32_t rhsUpper = rhs->upper(); |
| 943 | bool invertAfter = false; |
| 944 | |
| 945 | // If either operand is negative, bitwise-negate it, and arrange to negate |
| 946 | // the result; ~((~x)^y) == x^y. If both are negative the negations on the |
| 947 | // result cancel each other out; effectively this is (~x)^(~y) == x^y. |
| 948 | // These transformations reduce the number of cases we have to handle below. |
| 949 | if (lhsUpper < 0) { |
| 950 | lhsLower = ~lhsLower; |
| 951 | lhsUpper = ~lhsUpper; |
| 952 | std::swap(lhsLower, lhsUpper); |
| 953 | invertAfter = !invertAfter; |
| 954 | } |
| 955 | if (rhsUpper < 0) { |
| 956 | rhsLower = ~rhsLower; |
| 957 | rhsUpper = ~rhsUpper; |
| 958 | std::swap(rhsLower, rhsUpper); |
| 959 | invertAfter = !invertAfter; |
| 960 | } |
| 961 | |
| 962 | // Handle cases where lhs or rhs is always zero specially, because they're |
| 963 | // easy cases where we can be perfectly precise, and because it protects the |
| 964 | // std::countl_zero calls below from returning 32, which would be undefined |
| 965 | // behavior when used as the shift amount. |
| 966 | int32_t lower = INT32_MIN(-2147483647-1); |
| 967 | int32_t upper = INT32_MAX(2147483647); |
| 968 | if (lhsLower == 0 && lhsUpper == 0) { |
| 969 | upper = rhsUpper; |
| 970 | lower = rhsLower; |
| 971 | } else if (rhsLower == 0 && rhsUpper == 0) { |
| 972 | upper = lhsUpper; |
| 973 | lower = lhsLower; |
| 974 | } else if (lhsLower >= 0 && rhsLower >= 0) { |
| 975 | // Both operands are non-negative. The result will be non-negative. |
| 976 | lower = 0; |
| 977 | // To compute the upper value, take each operand's upper value and |
| 978 | // set all bits that don't correspond to leading zero bits in the |
| 979 | // other to one. For each one, this gives an upper bound for the |
| 980 | // result, so we can take the minimum between the two. |
| 981 | unsigned lhsLeadingZeros = std::countl_zero(uint32_t(lhsUpper)); |
| 982 | unsigned rhsLeadingZeros = std::countl_zero(uint32_t(rhsUpper)); |
| 983 | upper = std::min(rhsUpper | int32_t(UINT32_MAX(4294967295U) >> lhsLeadingZeros), |
| 984 | lhsUpper | int32_t(UINT32_MAX(4294967295U) >> rhsLeadingZeros)); |
| 985 | } |
| 986 | |
| 987 | // If we bitwise-negated one (but not both) of the operands above, apply the |
| 988 | // bitwise-negate to the result, completing ~((~x)^y) == x^y. |
| 989 | if (invertAfter) { |
| 990 | lower = ~lower; |
| 991 | upper = ~upper; |
| 992 | std::swap(lower, upper); |
| 993 | } |
| 994 | |
| 995 | return Range::NewInt32Range(alloc, lower, upper); |
| 996 | } |
| 997 | |
| 998 | Range* Range::not_(TempAllocator& alloc, const Range* op) { |
| 999 | MOZ_ASSERT(op->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(op->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(op->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("op->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 999); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "op->isInt32()" ")"); do { MOZ_CrashSequence (__null, 999); __attribute__((nomerge)) ::abort(); } while (false ); } } while (false); |
| 1000 | return Range::NewInt32Range(alloc, ~op->upper(), ~op->lower()); |
| 1001 | } |
| 1002 | |
| 1003 | Range* Range::mul(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 1004 | FractionalPartFlag newCanHaveFractionalPart = FractionalPartFlag( |
| 1005 | lhs->canHaveFractionalPart_ || rhs->canHaveFractionalPart_); |
| 1006 | |
| 1007 | NegativeZeroFlag newMayIncludeNegativeZero = NegativeZeroFlag( |
| 1008 | (lhs->canHaveSignBitSet() && rhs->canBeFiniteNonNegative()) || |
| 1009 | (rhs->canHaveSignBitSet() && lhs->canBeFiniteNonNegative())); |
| 1010 | |
| 1011 | uint16_t exponent; |
| 1012 | if (!lhs->canBeInfiniteOrNaN() && !rhs->canBeInfiniteOrNaN()) { |
| 1013 | // Two finite values. |
| 1014 | exponent = lhs->numBits() + rhs->numBits() - 1; |
| 1015 | if (exponent > Range::MaxFiniteExponent) { |
| 1016 | exponent = Range::IncludesInfinity; |
| 1017 | } |
| 1018 | } else if (!lhs->canBeNaN() && !rhs->canBeNaN() && |
| 1019 | !(lhs->canBeZero() && rhs->canBeInfiniteOrNaN()) && |
| 1020 | !(rhs->canBeZero() && lhs->canBeInfiniteOrNaN())) { |
| 1021 | // Two values that multiplied together won't produce a NaN. |
| 1022 | exponent = Range::IncludesInfinity; |
| 1023 | } else { |
| 1024 | // Could be anything. |
| 1025 | exponent = Range::IncludesInfinityAndNaN; |
| 1026 | } |
| 1027 | |
| 1028 | if (MissingAnyInt32Bounds(lhs, rhs)) { |
| 1029 | return new (alloc) |
| 1030 | Range(NoInt32LowerBound, NoInt32UpperBound, newCanHaveFractionalPart, |
| 1031 | newMayIncludeNegativeZero, exponent); |
| 1032 | } |
| 1033 | int64_t a = (int64_t)lhs->lower() * (int64_t)rhs->lower(); |
| 1034 | int64_t b = (int64_t)lhs->lower() * (int64_t)rhs->upper(); |
| 1035 | int64_t c = (int64_t)lhs->upper() * (int64_t)rhs->lower(); |
| 1036 | int64_t d = (int64_t)lhs->upper() * (int64_t)rhs->upper(); |
| 1037 | return new (alloc) |
| 1038 | Range(std::min(std::min(a, b), std::min(c, d)), |
| 1039 | std::max(std::max(a, b), std::max(c, d)), newCanHaveFractionalPart, |
| 1040 | newMayIncludeNegativeZero, exponent); |
| 1041 | } |
| 1042 | |
| 1043 | Range* Range::lsh(TempAllocator& alloc, const Range* lhs, int32_t c) { |
| 1044 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1044); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1044); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1045 | int32_t shift = c & 0x1f; |
| 1046 | |
| 1047 | // If the shift doesn't loose bits or shift bits into the sign bit, we |
| 1048 | // can simply compute the correct range by shifting. |
| 1049 | if ((int32_t)((uint32_t)lhs->lower() << shift << 1 >> shift >> 1) == |
| 1050 | lhs->lower() && |
| 1051 | (int32_t)((uint32_t)lhs->upper() << shift << 1 >> shift >> 1) == |
| 1052 | lhs->upper()) { |
| 1053 | return Range::NewInt32Range(alloc, uint32_t(lhs->lower()) << shift, |
| 1054 | uint32_t(lhs->upper()) << shift); |
| 1055 | } |
| 1056 | |
| 1057 | return Range::NewInt32Range(alloc, INT32_MIN(-2147483647-1), INT32_MAX(2147483647)); |
| 1058 | } |
| 1059 | |
| 1060 | Range* Range::rsh(TempAllocator& alloc, const Range* lhs, int32_t c) { |
| 1061 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1061); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1061); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1062 | int32_t shift = c & 0x1f; |
| 1063 | return Range::NewInt32Range(alloc, lhs->lower() >> shift, |
| 1064 | lhs->upper() >> shift); |
| 1065 | } |
| 1066 | |
| 1067 | Range* Range::ursh(TempAllocator& alloc, const Range* lhs, int32_t c) { |
| 1068 | // ursh's left operand is uint32, not int32, but for range analysis we |
| 1069 | // currently approximate it as int32. We assume here that the range has |
| 1070 | // already been adjusted accordingly by our callers. |
| 1071 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1071); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1071); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1072 | |
| 1073 | int32_t shift = c & 0x1f; |
| 1074 | |
| 1075 | // If the value is always non-negative or always negative, we can simply |
| 1076 | // compute the correct range by shifting. |
| 1077 | if (lhs->isFiniteNonNegative() || lhs->isFiniteNegative()) { |
| 1078 | return Range::NewUInt32Range(alloc, uint32_t(lhs->lower()) >> shift, |
| 1079 | uint32_t(lhs->upper()) >> shift); |
| 1080 | } |
| 1081 | |
| 1082 | // Otherwise return the most general range after the shift. |
| 1083 | return Range::NewUInt32Range(alloc, 0, UINT32_MAX(4294967295U) >> shift); |
| 1084 | } |
| 1085 | |
| 1086 | Range* Range::lsh(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 1087 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1087); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1087); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1088 | MOZ_ASSERT(rhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(rhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(rhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("rhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1088); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "rhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1088); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1089 | return Range::NewInt32Range(alloc, INT32_MIN(-2147483647-1), INT32_MAX(2147483647)); |
| 1090 | } |
| 1091 | |
| 1092 | Range* Range::rsh(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 1093 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1093); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1093); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1094 | MOZ_ASSERT(rhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(rhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(rhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("rhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1094); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "rhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1094); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1095 | |
| 1096 | // Canonicalize the shift range to 0 to 31. |
| 1097 | int32_t shiftLower = rhs->lower(); |
| 1098 | int32_t shiftUpper = rhs->upper(); |
| 1099 | if ((int64_t(shiftUpper) - int64_t(shiftLower)) >= 31) { |
| 1100 | shiftLower = 0; |
| 1101 | shiftUpper = 31; |
| 1102 | } else { |
| 1103 | shiftLower &= 0x1f; |
| 1104 | shiftUpper &= 0x1f; |
| 1105 | if (shiftLower > shiftUpper) { |
| 1106 | shiftLower = 0; |
| 1107 | shiftUpper = 31; |
| 1108 | } |
| 1109 | } |
| 1110 | MOZ_ASSERT(shiftLower >= 0 && shiftUpper <= 31)do { static_assert( mozilla::detail::AssertionConditionType< decltype(shiftLower >= 0 && shiftUpper <= 31)> ::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(shiftLower >= 0 && shiftUpper <= 31))) , 0))) { do { } while (false); MOZ_ReportAssertionFailure("shiftLower >= 0 && shiftUpper <= 31" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1110); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "shiftLower >= 0 && shiftUpper <= 31" ")"); do { MOZ_CrashSequence(__null, 1110); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 1111 | |
| 1112 | // The lhs bounds are signed, thus the minimum is either the lower bound |
| 1113 | // shift by the smallest shift if negative or the lower bound shifted by the |
| 1114 | // biggest shift otherwise. And the opposite for the maximum. |
| 1115 | int32_t lhsLower = lhs->lower(); |
| 1116 | int32_t min = lhsLower < 0 ? lhsLower >> shiftLower : lhsLower >> shiftUpper; |
| 1117 | int32_t lhsUpper = lhs->upper(); |
| 1118 | int32_t max = lhsUpper >= 0 ? lhsUpper >> shiftLower : lhsUpper >> shiftUpper; |
| 1119 | |
| 1120 | return Range::NewInt32Range(alloc, min, max); |
| 1121 | } |
| 1122 | |
| 1123 | Range* Range::ursh(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 1124 | // ursh's left operand is uint32, not int32, but for range analysis we |
| 1125 | // currently approximate it as int32. We assume here that the range has |
| 1126 | // already been adjusted accordingly by our callers. |
| 1127 | MOZ_ASSERT(lhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(lhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(lhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("lhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1127); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "lhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1127); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1128 | MOZ_ASSERT(rhs->isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(rhs->isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(rhs->isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("rhs->isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1128); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "rhs->isInt32()" ")"); do { MOZ_CrashSequence (__null, 1128); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1129 | return Range::NewUInt32Range( |
| 1130 | alloc, 0, lhs->isFiniteNonNegative() ? lhs->upper() : UINT32_MAX(4294967295U)); |
| 1131 | } |
| 1132 | |
| 1133 | Range* Range::abs(TempAllocator& alloc, const Range* op) { |
| 1134 | int32_t l = op->lower_; |
| 1135 | int32_t u = op->upper_; |
| 1136 | FractionalPartFlag canHaveFractionalPart = op->canHaveFractionalPart_; |
| 1137 | |
| 1138 | // Abs never produces a negative zero. |
| 1139 | NegativeZeroFlag canBeNegativeZero = ExcludesNegativeZero; |
| 1140 | |
| 1141 | return new (alloc) Range( |
| 1142 | std::max(std::max(int32_t(0), l), u == INT32_MIN(-2147483647-1) ? INT32_MAX(2147483647) : -u), true, |
| 1143 | std::max(std::max(int32_t(0), u), l == INT32_MIN(-2147483647-1) ? INT32_MAX(2147483647) : -l), |
| 1144 | op->hasInt32Bounds() && l != INT32_MIN(-2147483647-1), canHaveFractionalPart, |
| 1145 | canBeNegativeZero, op->max_exponent_); |
| 1146 | } |
| 1147 | |
| 1148 | Range* Range::min(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 1149 | // If either operand is NaN, the result is NaN. |
| 1150 | if (lhs->canBeNaN() || rhs->canBeNaN()) { |
| 1151 | return nullptr; |
| 1152 | } |
| 1153 | |
| 1154 | FractionalPartFlag newCanHaveFractionalPart = FractionalPartFlag( |
| 1155 | lhs->canHaveFractionalPart_ || rhs->canHaveFractionalPart_); |
| 1156 | NegativeZeroFlag newMayIncludeNegativeZero = |
| 1157 | NegativeZeroFlag(lhs->canBeNegativeZero_ || rhs->canBeNegativeZero_); |
| 1158 | |
| 1159 | return new (alloc) Range(std::min(lhs->lower_, rhs->lower_), |
| 1160 | lhs->hasInt32LowerBound_ && rhs->hasInt32LowerBound_, |
| 1161 | std::min(lhs->upper_, rhs->upper_), |
| 1162 | lhs->hasInt32UpperBound_ || rhs->hasInt32UpperBound_, |
| 1163 | newCanHaveFractionalPart, newMayIncludeNegativeZero, |
| 1164 | std::max(lhs->max_exponent_, rhs->max_exponent_)); |
| 1165 | } |
| 1166 | |
| 1167 | Range* Range::max(TempAllocator& alloc, const Range* lhs, const Range* rhs) { |
| 1168 | // If either operand is NaN, the result is NaN. |
| 1169 | if (lhs->canBeNaN() || rhs->canBeNaN()) { |
| 1170 | return nullptr; |
| 1171 | } |
| 1172 | |
| 1173 | FractionalPartFlag newCanHaveFractionalPart = FractionalPartFlag( |
| 1174 | lhs->canHaveFractionalPart_ || rhs->canHaveFractionalPart_); |
| 1175 | NegativeZeroFlag newMayIncludeNegativeZero = |
| 1176 | NegativeZeroFlag(lhs->canBeNegativeZero_ || rhs->canBeNegativeZero_); |
| 1177 | |
| 1178 | return new (alloc) Range(std::max(lhs->lower_, rhs->lower_), |
| 1179 | lhs->hasInt32LowerBound_ || rhs->hasInt32LowerBound_, |
| 1180 | std::max(lhs->upper_, rhs->upper_), |
| 1181 | lhs->hasInt32UpperBound_ && rhs->hasInt32UpperBound_, |
| 1182 | newCanHaveFractionalPart, newMayIncludeNegativeZero, |
| 1183 | std::max(lhs->max_exponent_, rhs->max_exponent_)); |
| 1184 | } |
| 1185 | |
| 1186 | Range* Range::floor(TempAllocator& alloc, const Range* op) { |
| 1187 | Range* copy = new (alloc) Range(*op); |
| 1188 | // Decrement lower bound of copy range if op have a factional part and lower |
| 1189 | // bound is Int32 defined. Also we avoid to decrement when op have a |
| 1190 | // fractional part but lower_ >= JSVAL_INT_MAX. |
| 1191 | if (op->canHaveFractionalPart() && op->hasInt32LowerBound()) { |
| 1192 | copy->setLowerInit(int64_t(copy->lower_) - 1); |
| 1193 | } |
| 1194 | |
| 1195 | // Also refine max_exponent_ because floor may have decremented int value |
| 1196 | // If we've got int32 defined bounds, just deduce it using defined bounds. |
| 1197 | // But, if we don't have those, value's max_exponent_ may have changed. |
| 1198 | // Because we're looking to maintain an over estimation, if we can, |
| 1199 | // we increment it. |
| 1200 | if (copy->hasInt32Bounds()) |
| 1201 | copy->max_exponent_ = copy->exponentImpliedByInt32Bounds(); |
| 1202 | else if (copy->max_exponent_ < MaxFiniteExponent) |
| 1203 | copy->max_exponent_++; |
| 1204 | |
| 1205 | copy->canHaveFractionalPart_ = ExcludesFractionalParts; |
| 1206 | copy->assertInvariants(); |
| 1207 | return copy; |
| 1208 | } |
| 1209 | |
| 1210 | Range* Range::ceil(TempAllocator& alloc, const Range* op) { |
| 1211 | Range* copy = new (alloc) Range(*op); |
| 1212 | |
| 1213 | // We need to refine max_exponent_ because ceil may have incremented the int |
| 1214 | // value. If we have got int32 bounds defined, just deduce it using the |
| 1215 | // defined bounds. Else we can just increment its value, as we are looking to |
| 1216 | // maintain an over estimation. |
| 1217 | if (copy->hasInt32Bounds()) { |
| 1218 | copy->max_exponent_ = copy->exponentImpliedByInt32Bounds(); |
| 1219 | } else if (copy->max_exponent_ < MaxFiniteExponent) { |
| 1220 | copy->max_exponent_++; |
| 1221 | } |
| 1222 | |
| 1223 | // If the range is definitely above 0 or below -1, we don't need to include |
| 1224 | // -0; otherwise we do. |
| 1225 | |
| 1226 | copy->canBeNegativeZero_ = ((copy->lower_ > 0) || (copy->upper_ <= -1)) |
| 1227 | ? copy->canBeNegativeZero_ |
| 1228 | : IncludesNegativeZero; |
| 1229 | |
| 1230 | copy->canHaveFractionalPart_ = ExcludesFractionalParts; |
| 1231 | copy->assertInvariants(); |
| 1232 | return copy; |
| 1233 | } |
| 1234 | |
| 1235 | Range* Range::sign(TempAllocator& alloc, const Range* op) { |
| 1236 | if (op->canBeNaN()) { |
| 1237 | return nullptr; |
| 1238 | } |
| 1239 | |
| 1240 | return new (alloc) |
| 1241 | Range(std::clamp(op->lower_, -1, 1), std::clamp(op->upper_, -1, 1), |
| 1242 | Range::ExcludesFractionalParts, |
| 1243 | NegativeZeroFlag(op->canBeNegativeZero()), 0); |
| 1244 | } |
| 1245 | |
| 1246 | Range* Range::NaNToZero(TempAllocator& alloc, const Range* op) { |
| 1247 | Range* copy = new (alloc) Range(*op); |
| 1248 | if (copy->canBeNaN()) { |
| 1249 | copy->max_exponent_ = Range::IncludesInfinity; |
| 1250 | if (!copy->canBeZero()) { |
| 1251 | Range zero; |
| 1252 | zero.setDoubleSingleton(0); |
| 1253 | copy->unionWith(&zero); |
| 1254 | } |
| 1255 | } |
| 1256 | copy->refineToExcludeNegativeZero(); |
| 1257 | return copy; |
| 1258 | } |
| 1259 | |
| 1260 | bool Range::negativeZeroMul(const Range* lhs, const Range* rhs) { |
| 1261 | // The result can only be negative zero if both sides are finite and they |
| 1262 | // have differing signs. |
| 1263 | return (lhs->canHaveSignBitSet() && rhs->canBeFiniteNonNegative()) || |
| 1264 | (rhs->canHaveSignBitSet() && lhs->canBeFiniteNonNegative()); |
| 1265 | } |
| 1266 | |
| 1267 | bool Range::update(const Range* other) { |
| 1268 | bool changed = lower_ != other->lower_ || |
| 1269 | hasInt32LowerBound_ != other->hasInt32LowerBound_ || |
| 1270 | upper_ != other->upper_ || |
| 1271 | hasInt32UpperBound_ != other->hasInt32UpperBound_ || |
| 1272 | canHaveFractionalPart_ != other->canHaveFractionalPart_ || |
| 1273 | canBeNegativeZero_ != other->canBeNegativeZero_ || |
| 1274 | max_exponent_ != other->max_exponent_; |
| 1275 | if (changed) { |
| 1276 | lower_ = other->lower_; |
| 1277 | hasInt32LowerBound_ = other->hasInt32LowerBound_; |
| 1278 | upper_ = other->upper_; |
| 1279 | hasInt32UpperBound_ = other->hasInt32UpperBound_; |
| 1280 | canHaveFractionalPart_ = other->canHaveFractionalPart_; |
| 1281 | canBeNegativeZero_ = other->canBeNegativeZero_; |
| 1282 | max_exponent_ = other->max_exponent_; |
| 1283 | assertInvariants(); |
| 1284 | } |
| 1285 | |
| 1286 | return changed; |
| 1287 | } |
| 1288 | |
| 1289 | /////////////////////////////////////////////////////////////////////////////// |
| 1290 | // Range Computation for MIR Nodes |
| 1291 | /////////////////////////////////////////////////////////////////////////////// |
| 1292 | |
| 1293 | void MPhi::computeRange(TempAllocator& alloc) { |
| 1294 | if (type() != MIRType::Int32 && type() != MIRType::Double) { |
| 1295 | return; |
| 1296 | } |
| 1297 | |
| 1298 | Range* range = nullptr; |
| 1299 | for (size_t i = 0, e = numOperands(); i < e; i++) { |
| 1300 | if (getOperand(i)->block()->unreachable()) { |
| 1301 | JitSpew(JitSpew_Range, "Ignoring unreachable input %u", |
| 1302 | getOperand(i)->id()); |
| 1303 | continue; |
| 1304 | } |
| 1305 | |
| 1306 | // Peek at the pre-bailout range so we can take a short-cut; if any of |
| 1307 | // the operands has an unknown range, this phi has an unknown range. |
| 1308 | if (!getOperand(i)->range()) { |
| 1309 | return; |
| 1310 | } |
| 1311 | |
| 1312 | Range input(getOperand(i)); |
| 1313 | |
| 1314 | if (range) { |
| 1315 | range->unionWith(&input); |
| 1316 | } else { |
| 1317 | range = new (alloc) Range(input); |
| 1318 | } |
| 1319 | } |
| 1320 | |
| 1321 | setRange(range); |
| 1322 | } |
| 1323 | |
| 1324 | void MBeta::computeRange(TempAllocator& alloc) { |
| 1325 | bool emptyRange = false; |
| 1326 | |
| 1327 | Range opRange(getOperand(0)); |
| 1328 | Range* range = Range::intersect(alloc, &opRange, comparison_, &emptyRange); |
| 1329 | if (emptyRange) { |
| 1330 | JitSpew(JitSpew_Range, "Marking block for inst %u unreachable", id()); |
| 1331 | block()->setUnreachableUnchecked(); |
| 1332 | } else { |
| 1333 | setRange(range); |
| 1334 | } |
| 1335 | } |
| 1336 | |
| 1337 | void MConstant::computeRange(TempAllocator& alloc) { |
| 1338 | if (isTypeRepresentableAsDouble()) { |
| 1339 | double d = numberToDouble(); |
| 1340 | setRange(Range::NewDoubleSingletonRange(alloc, d)); |
| 1341 | } else if (type() == MIRType::Boolean) { |
| 1342 | bool b = toBoolean(); |
| 1343 | setRange(Range::NewInt32Range(alloc, b, b)); |
| 1344 | } |
| 1345 | } |
| 1346 | |
| 1347 | void MCharCodeAt::computeRange(TempAllocator& alloc) { |
| 1348 | // ECMA 262 says that the integer will be non-negative and at most 65535. |
| 1349 | setRange(Range::NewInt32Range(alloc, 0, unicode::UTF16Max)); |
| 1350 | } |
| 1351 | |
| 1352 | void MCodePointAt::computeRange(TempAllocator& alloc) { |
| 1353 | setRange(Range::NewInt32Range(alloc, 0, unicode::NonBMPMax)); |
| 1354 | } |
| 1355 | |
| 1356 | void MClampToUint8::computeRange(TempAllocator& alloc) { |
| 1357 | setRange(Range::NewUInt32Range(alloc, 0, 255)); |
| 1358 | } |
| 1359 | |
| 1360 | void MBitAnd::computeRange(TempAllocator& alloc) { |
| 1361 | if (type() != MIRType::Int32) { |
| 1362 | return; |
| 1363 | } |
| 1364 | |
| 1365 | Range left(getOperand(0)); |
| 1366 | Range right(getOperand(1)); |
| 1367 | left.wrapAroundToInt32(); |
| 1368 | right.wrapAroundToInt32(); |
| 1369 | |
| 1370 | setRange(Range::and_(alloc, &left, &right)); |
| 1371 | } |
| 1372 | |
| 1373 | void MBitOr::computeRange(TempAllocator& alloc) { |
| 1374 | if (type() != MIRType::Int32) { |
| 1375 | return; |
| 1376 | } |
| 1377 | |
| 1378 | Range left(getOperand(0)); |
| 1379 | Range right(getOperand(1)); |
| 1380 | left.wrapAroundToInt32(); |
| 1381 | right.wrapAroundToInt32(); |
| 1382 | |
| 1383 | setRange(Range::or_(alloc, &left, &right)); |
| 1384 | } |
| 1385 | |
| 1386 | void MBitXor::computeRange(TempAllocator& alloc) { |
| 1387 | if (type() != MIRType::Int32) { |
| 1388 | return; |
| 1389 | } |
| 1390 | |
| 1391 | Range left(getOperand(0)); |
| 1392 | Range right(getOperand(1)); |
| 1393 | left.wrapAroundToInt32(); |
| 1394 | right.wrapAroundToInt32(); |
| 1395 | |
| 1396 | setRange(Range::xor_(alloc, &left, &right)); |
| 1397 | } |
| 1398 | |
| 1399 | void MBitNot::computeRange(TempAllocator& alloc) { |
| 1400 | if (type() == MIRType::Int64) { |
| 1401 | return; |
| 1402 | } |
| 1403 | MOZ_ASSERT(type() == MIRType::Int32)do { static_assert( mozilla::detail::AssertionConditionType< decltype(type() == MIRType::Int32)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(type() == MIRType::Int32))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("type() == MIRType::Int32" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1403); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "type() == MIRType::Int32" ")"); do { MOZ_CrashSequence (__null, 1403); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1404 | |
| 1405 | Range op(getOperand(0)); |
| 1406 | op.wrapAroundToInt32(); |
| 1407 | |
| 1408 | setRange(Range::not_(alloc, &op)); |
| 1409 | } |
| 1410 | |
| 1411 | void MLsh::computeRange(TempAllocator& alloc) { |
| 1412 | if (type() != MIRType::Int32) { |
| 1413 | return; |
| 1414 | } |
| 1415 | |
| 1416 | Range left(getOperand(0)); |
| 1417 | Range right(getOperand(1)); |
| 1418 | left.wrapAroundToInt32(); |
| 1419 | |
| 1420 | MConstant* rhsConst = getOperand(1)->maybeConstantValue(); |
| 1421 | if (rhsConst && rhsConst->type() == MIRType::Int32) { |
| 1422 | int32_t c = rhsConst->toInt32(); |
| 1423 | setRange(Range::lsh(alloc, &left, c)); |
| 1424 | return; |
| 1425 | } |
| 1426 | |
| 1427 | right.wrapAroundToShiftCount(); |
| 1428 | setRange(Range::lsh(alloc, &left, &right)); |
| 1429 | } |
| 1430 | |
| 1431 | void MRsh::computeRange(TempAllocator& alloc) { |
| 1432 | if (type() != MIRType::Int32) { |
| 1433 | return; |
| 1434 | } |
| 1435 | |
| 1436 | Range left(getOperand(0)); |
| 1437 | Range right(getOperand(1)); |
| 1438 | left.wrapAroundToInt32(); |
| 1439 | |
| 1440 | MConstant* rhsConst = getOperand(1)->maybeConstantValue(); |
| 1441 | if (rhsConst && rhsConst->type() == MIRType::Int32) { |
| 1442 | int32_t c = rhsConst->toInt32(); |
| 1443 | setRange(Range::rsh(alloc, &left, c)); |
| 1444 | return; |
| 1445 | } |
| 1446 | |
| 1447 | right.wrapAroundToShiftCount(); |
| 1448 | setRange(Range::rsh(alloc, &left, &right)); |
| 1449 | } |
| 1450 | |
| 1451 | void MUrsh::computeRange(TempAllocator& alloc) { |
| 1452 | if (type() != MIRType::Int32) { |
| 1453 | return; |
| 1454 | } |
| 1455 | |
| 1456 | Range left(getOperand(0)); |
| 1457 | Range right(getOperand(1)); |
| 1458 | |
| 1459 | // ursh can be thought of as converting its left operand to uint32, or it |
| 1460 | // can be thought of as converting its left operand to int32, and then |
| 1461 | // reinterpreting the int32 bits as a uint32 value. Both approaches yield |
| 1462 | // the same result. Since we lack support for full uint32 ranges, we use |
| 1463 | // the second interpretation, though it does cause us to be conservative. |
| 1464 | left.wrapAroundToInt32(); |
| 1465 | right.wrapAroundToShiftCount(); |
| 1466 | |
| 1467 | MConstant* rhsConst = getOperand(1)->maybeConstantValue(); |
| 1468 | if (rhsConst && rhsConst->type() == MIRType::Int32) { |
| 1469 | int32_t c = rhsConst->toInt32(); |
| 1470 | setRange(Range::ursh(alloc, &left, c)); |
| 1471 | } else { |
| 1472 | setRange(Range::ursh(alloc, &left, &right)); |
| 1473 | } |
| 1474 | |
| 1475 | MOZ_ASSERT(range()->lower() >= 0)do { static_assert( mozilla::detail::AssertionConditionType< decltype(range()->lower() >= 0)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(range()->lower() >= 0) )), 0))) { do { } while (false); MOZ_ReportAssertionFailure("range()->lower() >= 0" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1475); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "range()->lower() >= 0" ")"); do { MOZ_CrashSequence (__null, 1475); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1476 | } |
| 1477 | |
| 1478 | void MAbs::computeRange(TempAllocator& alloc) { |
| 1479 | if (type() != MIRType::Int32 && type() != MIRType::Double) { |
| 1480 | return; |
| 1481 | } |
| 1482 | |
| 1483 | Range other(getOperand(0)); |
| 1484 | Range* next = Range::abs(alloc, &other); |
| 1485 | if (implicitTruncate_) { |
| 1486 | next->wrapAroundToInt32(); |
| 1487 | } |
| 1488 | setRange(next); |
| 1489 | } |
| 1490 | |
| 1491 | void MFloor::computeRange(TempAllocator& alloc) { |
| 1492 | Range other(getOperand(0)); |
| 1493 | setRange(Range::floor(alloc, &other)); |
| 1494 | } |
| 1495 | |
| 1496 | void MCeil::computeRange(TempAllocator& alloc) { |
| 1497 | Range other(getOperand(0)); |
| 1498 | setRange(Range::ceil(alloc, &other)); |
| 1499 | } |
| 1500 | |
| 1501 | void MClz::computeRange(TempAllocator& alloc) { |
| 1502 | if (type() != MIRType::Int32) { |
| 1503 | return; |
| 1504 | } |
| 1505 | setRange(Range::NewUInt32Range(alloc, 0, 32)); |
| 1506 | } |
| 1507 | |
| 1508 | void MCtz::computeRange(TempAllocator& alloc) { |
| 1509 | if (type() != MIRType::Int32) { |
| 1510 | return; |
| 1511 | } |
| 1512 | setRange(Range::NewUInt32Range(alloc, 0, 32)); |
| 1513 | } |
| 1514 | |
| 1515 | void MPopcnt::computeRange(TempAllocator& alloc) { |
| 1516 | if (type() != MIRType::Int32) { |
| 1517 | return; |
| 1518 | } |
| 1519 | setRange(Range::NewUInt32Range(alloc, 0, 32)); |
| 1520 | } |
| 1521 | |
| 1522 | void MMinMax::computeRange(TempAllocator& alloc) { |
| 1523 | if (type() != MIRType::Int32 && type() != MIRType::Double) { |
| 1524 | return; |
| 1525 | } |
| 1526 | |
| 1527 | Range left(getOperand(0)); |
| 1528 | Range right(getOperand(1)); |
| 1529 | setRange(isMax() ? Range::max(alloc, &left, &right) |
| 1530 | : Range::min(alloc, &left, &right)); |
| 1531 | } |
| 1532 | |
| 1533 | void MAdd::computeRange(TempAllocator& alloc) { |
| 1534 | if (type() != MIRType::Int32 && type() != MIRType::Double) { |
| 1535 | return; |
| 1536 | } |
| 1537 | Range left(getOperand(0)); |
| 1538 | Range right(getOperand(1)); |
| 1539 | Range* next = Range::add(alloc, &left, &right); |
| 1540 | if (isTruncated()) { |
| 1541 | next->wrapAroundToInt32(); |
| 1542 | } |
| 1543 | setRange(next); |
| 1544 | } |
| 1545 | |
| 1546 | void MSub::computeRange(TempAllocator& alloc) { |
| 1547 | if (type() != MIRType::Int32 && type() != MIRType::Double) { |
| 1548 | return; |
| 1549 | } |
| 1550 | Range left(getOperand(0)); |
| 1551 | Range right(getOperand(1)); |
| 1552 | Range* next = Range::sub(alloc, &left, &right); |
| 1553 | if (isTruncated()) { |
| 1554 | next->wrapAroundToInt32(); |
| 1555 | } |
| 1556 | setRange(next); |
| 1557 | } |
| 1558 | |
| 1559 | void MMul::computeRange(TempAllocator& alloc) { |
| 1560 | if (type() != MIRType::Int32 && type() != MIRType::Double) { |
| 1561 | return; |
| 1562 | } |
| 1563 | Range left(getOperand(0)); |
| 1564 | Range right(getOperand(1)); |
| 1565 | if (canBeNegativeZero()) { |
| 1566 | canBeNegativeZero_ = Range::negativeZeroMul(&left, &right); |
| 1567 | } |
| 1568 | Range* next = Range::mul(alloc, &left, &right); |
| 1569 | if (!next->canBeNegativeZero()) { |
| 1570 | canBeNegativeZero_ = false; |
| 1571 | } |
| 1572 | // Truncated multiplications could overflow in both directions |
| 1573 | if (isTruncated()) { |
| 1574 | next->wrapAroundToInt32(); |
| 1575 | } |
| 1576 | setRange(next); |
| 1577 | } |
| 1578 | |
| 1579 | void MMod::computeRange(TempAllocator& alloc) { |
| 1580 | if (type() != MIRType::Int32 && type() != MIRType::Double) { |
| 1581 | return; |
| 1582 | } |
| 1583 | Range lhs(getOperand(0)); |
| 1584 | Range rhs(getOperand(1)); |
| 1585 | |
| 1586 | // If either operand is a NaN, the result is NaN. This also conservatively |
| 1587 | // handles Infinity cases. |
| 1588 | if (!lhs.hasInt32Bounds() || !rhs.hasInt32Bounds()) { |
| 1589 | return; |
| 1590 | } |
| 1591 | |
| 1592 | // If RHS can be zero, the result can be NaN. |
| 1593 | if (rhs.lower() <= 0 && rhs.upper() >= 0) { |
| 1594 | return; |
| 1595 | } |
| 1596 | |
| 1597 | // If both operands are non-negative integers, we can optimize this to an |
| 1598 | // unsigned mod. |
| 1599 | if (type() == MIRType::Int32 && rhs.lower() > 0) { |
| 1600 | bool hasDoubles = lhs.lower() < 0 || lhs.canHaveFractionalPart() || |
| 1601 | rhs.canHaveFractionalPart(); |
| 1602 | // It is not possible to check that lhs.lower() >= 0, since the range |
| 1603 | // of a ursh with rhs a 0 constant is wrapped around the int32 range in |
| 1604 | // Range::Range(). However, IsUint32Type() will only return true for |
| 1605 | // nodes that lie in the range [0, UINT32_MAX]. |
| 1606 | bool hasUint32s = |
| 1607 | IsUint32Type(getOperand(0)) && |
| 1608 | getOperand(1)->type() == MIRType::Int32 && |
| 1609 | (IsUint32Type(getOperand(1)) || getOperand(1)->isConstant()); |
| 1610 | if (!hasDoubles || hasUint32s) { |
| 1611 | unsigned_ = true; |
| 1612 | } |
| 1613 | } |
| 1614 | |
| 1615 | // For unsigned mod, we have to convert both operands to unsigned. |
| 1616 | // Note that we handled the case of a zero rhs above. |
| 1617 | if (unsigned_) { |
| 1618 | // The result of an unsigned mod will never be unsigned-greater than |
| 1619 | // either operand. |
| 1620 | uint32_t lhsBound = std::max<uint32_t>(lhs.lower(), lhs.upper()); |
| 1621 | uint32_t rhsBound = std::max<uint32_t>(rhs.lower(), rhs.upper()); |
| 1622 | |
| 1623 | // If either range crosses through -1 as a signed value, it could be |
| 1624 | // the maximum unsigned value when interpreted as unsigned. If the range |
| 1625 | // doesn't include -1, then the simple max value we computed above is |
| 1626 | // correct. |
| 1627 | if (lhs.lower() <= -1 && lhs.upper() >= -1) { |
| 1628 | lhsBound = UINT32_MAX(4294967295U); |
| 1629 | } |
| 1630 | if (rhs.lower() <= -1 && rhs.upper() >= -1) { |
| 1631 | rhsBound = UINT32_MAX(4294967295U); |
| 1632 | } |
| 1633 | |
| 1634 | // The result will never be equal to the rhs, and we shouldn't have |
| 1635 | // any rounding to worry about. |
| 1636 | MOZ_ASSERT(!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart ())>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart ()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1636); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart()" ")"); do { MOZ_CrashSequence(__null, 1636); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 1637 | --rhsBound; |
| 1638 | |
| 1639 | // This gives us two upper bounds, so we can take the best one. |
| 1640 | setRange(Range::NewUInt32Range(alloc, 0, std::min(lhsBound, rhsBound))); |
| 1641 | return; |
| 1642 | } |
| 1643 | |
| 1644 | // Math.abs(lhs % rhs) == Math.abs(lhs) % Math.abs(rhs). |
| 1645 | // First, the absolute value of the result will always be less than the |
| 1646 | // absolute value of rhs. (And if rhs is zero, the result is NaN). |
| 1647 | int64_t a = Abs<int64_t>(rhs.lower()); |
| 1648 | int64_t b = Abs<int64_t>(rhs.upper()); |
| 1649 | if (a == 0 && b == 0) { |
| 1650 | return; |
| 1651 | } |
| 1652 | int64_t rhsAbsBound = std::max(a, b); |
| 1653 | |
| 1654 | // If the value is known to be integer, less-than abs(rhs) is equivalent |
| 1655 | // to less-than-or-equal abs(rhs)-1. This is important for being able to |
| 1656 | // say that the result of x%256 is an 8-bit unsigned number. |
| 1657 | if (!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart()) { |
| 1658 | --rhsAbsBound; |
| 1659 | } |
| 1660 | |
| 1661 | // Next, the absolute value of the result will never be greater than the |
| 1662 | // absolute value of lhs. |
| 1663 | int64_t lhsAbsBound = |
| 1664 | std::max(Abs<int64_t>(lhs.lower()), Abs<int64_t>(lhs.upper())); |
| 1665 | |
| 1666 | // This gives us two upper bounds, so we can take the best one. |
| 1667 | int64_t absBound = std::min(lhsAbsBound, rhsAbsBound); |
| 1668 | |
| 1669 | // Now consider the sign of the result. |
| 1670 | // If lhs is non-negative, the result will be non-negative. |
| 1671 | // If lhs is non-positive, the result will be non-positive. |
| 1672 | int64_t lower = lhs.lower() >= 0 ? 0 : -absBound; |
| 1673 | int64_t upper = lhs.upper() <= 0 ? 0 : absBound; |
| 1674 | |
| 1675 | Range::FractionalPartFlag newCanHaveFractionalPart = |
| 1676 | Range::FractionalPartFlag(lhs.canHaveFractionalPart() || |
| 1677 | rhs.canHaveFractionalPart()); |
| 1678 | |
| 1679 | // If the lhs can have the sign bit set and we can return a zero, it'll be a |
| 1680 | // negative zero. |
| 1681 | Range::NegativeZeroFlag newMayIncludeNegativeZero = |
| 1682 | Range::NegativeZeroFlag(lhs.canHaveSignBitSet()); |
| 1683 | |
| 1684 | setRange(new (alloc) Range(lower, upper, newCanHaveFractionalPart, |
| 1685 | newMayIncludeNegativeZero, |
| 1686 | std::min(lhs.exponent(), rhs.exponent()))); |
| 1687 | } |
| 1688 | |
| 1689 | void MDiv::computeRange(TempAllocator& alloc) { |
| 1690 | if (type() != MIRType::Int32 && type() != MIRType::Double) { |
| 1691 | return; |
| 1692 | } |
| 1693 | Range lhs(getOperand(0)); |
| 1694 | Range rhs(getOperand(1)); |
| 1695 | |
| 1696 | // If either operand is a NaN, the result is NaN. This also conservatively |
| 1697 | // handles Infinity cases. |
| 1698 | if (!lhs.hasInt32Bounds() || !rhs.hasInt32Bounds()) { |
| 1699 | return; |
| 1700 | } |
| 1701 | |
| 1702 | // Something simple for now: When dividing by a positive rhs, the result |
| 1703 | // won't be further from zero than lhs. |
| 1704 | if (lhs.lower() >= 0 && rhs.lower() >= 1) { |
| 1705 | setRange(new (alloc) Range(0, lhs.upper(), Range::IncludesFractionalParts, |
| 1706 | Range::IncludesNegativeZero, lhs.exponent())); |
| 1707 | } else if (unsigned_ && rhs.lower() >= 1) { |
| 1708 | // We shouldn't set the unsigned flag if the inputs can have |
| 1709 | // fractional parts. |
| 1710 | MOZ_ASSERT(!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart ())>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart ()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1710); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "!lhs.canHaveFractionalPart() && !rhs.canHaveFractionalPart()" ")"); do { MOZ_CrashSequence(__null, 1710); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 1711 | // We shouldn't set the unsigned flag if the inputs can be |
| 1712 | // negative zero. |
| 1713 | MOZ_ASSERT(!lhs.canBeNegativeZero() && !rhs.canBeNegativeZero())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!lhs.canBeNegativeZero() && !rhs.canBeNegativeZero ())>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(!lhs.canBeNegativeZero() && !rhs.canBeNegativeZero ()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("!lhs.canBeNegativeZero() && !rhs.canBeNegativeZero()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1713); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "!lhs.canBeNegativeZero() && !rhs.canBeNegativeZero()" ")"); do { MOZ_CrashSequence(__null, 1713); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 1714 | // Unsigned division by a non-zero rhs will return a uint32 value. |
| 1715 | setRange(Range::NewUInt32Range(alloc, 0, UINT32_MAX(4294967295U))); |
| 1716 | } |
| 1717 | } |
| 1718 | |
| 1719 | void MSqrt::computeRange(TempAllocator& alloc) { |
| 1720 | Range input(getOperand(0)); |
| 1721 | |
| 1722 | // If either operand is a NaN, the result is NaN. This also conservatively |
| 1723 | // handles Infinity cases. |
| 1724 | if (!input.hasInt32Bounds()) { |
| 1725 | return; |
| 1726 | } |
| 1727 | |
| 1728 | // Sqrt of a negative non-zero value is NaN. |
| 1729 | if (input.lower() < 0) { |
| 1730 | return; |
| 1731 | } |
| 1732 | |
| 1733 | // Something simple for now: When taking the sqrt of a positive value, the |
| 1734 | // result won't be further from zero than the input. |
| 1735 | // And, sqrt of an integer may have a fractional part. |
| 1736 | setRange(new (alloc) Range(0, input.upper(), Range::IncludesFractionalParts, |
| 1737 | input.canBeNegativeZero(), input.exponent())); |
| 1738 | } |
| 1739 | |
| 1740 | void MToDouble::computeRange(TempAllocator& alloc) { |
| 1741 | setRange(new (alloc) Range(getOperand(0))); |
| 1742 | } |
| 1743 | |
| 1744 | void MToFloat32::computeRange(TempAllocator& alloc) {} |
| 1745 | |
| 1746 | void MTruncateToInt32::computeRange(TempAllocator& alloc) { |
| 1747 | Range* output = new (alloc) Range(getOperand(0)); |
| 1748 | output->wrapAroundToInt32(); |
| 1749 | setRange(output); |
| 1750 | } |
| 1751 | |
| 1752 | void MToNumberInt32::computeRange(TempAllocator& alloc) { |
| 1753 | // No clamping since this computes the range *before* bailouts. |
| 1754 | setRange(new (alloc) Range(getOperand(0))); |
| 1755 | } |
| 1756 | |
| 1757 | void MBooleanToInt32::computeRange(TempAllocator& alloc) { |
| 1758 | setRange(Range::NewUInt32Range(alloc, 0, 1)); |
| 1759 | } |
| 1760 | |
| 1761 | void MLimitedTruncate::computeRange(TempAllocator& alloc) { |
| 1762 | Range* output = new (alloc) Range(input()); |
| 1763 | setRange(output); |
| 1764 | } |
| 1765 | |
| 1766 | static Range* GetArrayBufferViewRange(TempAllocator& alloc, Scalar::Type type) { |
| 1767 | switch (type) { |
| 1768 | case Scalar::Uint8Clamped: |
| 1769 | case Scalar::Uint8: |
| 1770 | return Range::NewUInt32Range(alloc, 0, UINT8_MAX(255)); |
| 1771 | case Scalar::Uint16: |
| 1772 | return Range::NewUInt32Range(alloc, 0, UINT16_MAX(65535)); |
| 1773 | case Scalar::Uint32: |
| 1774 | return Range::NewUInt32Range(alloc, 0, UINT32_MAX(4294967295U)); |
| 1775 | |
| 1776 | case Scalar::Int8: |
| 1777 | return Range::NewInt32Range(alloc, INT8_MIN(-128), INT8_MAX(127)); |
| 1778 | case Scalar::Int16: |
| 1779 | return Range::NewInt32Range(alloc, INT16_MIN(-32767-1), INT16_MAX(32767)); |
| 1780 | case Scalar::Int32: |
| 1781 | return Range::NewInt32Range(alloc, INT32_MIN(-2147483647-1), INT32_MAX(2147483647)); |
| 1782 | |
| 1783 | case Scalar::BigInt64: |
| 1784 | case Scalar::BigUint64: |
| 1785 | case Scalar::Int64: |
| 1786 | case Scalar::Simd128: |
| 1787 | case Scalar::Float16: |
| 1788 | case Scalar::Float32: |
| 1789 | case Scalar::Float64: |
| 1790 | case Scalar::MaxTypedArrayViewType: |
| 1791 | break; |
| 1792 | } |
| 1793 | return nullptr; |
| 1794 | } |
| 1795 | |
| 1796 | void MLoadUnboxedScalar::computeRange(TempAllocator& alloc) { |
| 1797 | // We have an Int32 type and if this is a UInt32 load it may produce a value |
| 1798 | // outside of our range, but we have a bailout to handle those cases. |
| 1799 | setRange(GetArrayBufferViewRange(alloc, storageType())); |
| 1800 | } |
| 1801 | |
| 1802 | void MLoadDataViewElement::computeRange(TempAllocator& alloc) { |
| 1803 | // We have an Int32 type and if this is a UInt32 load it may produce a value |
| 1804 | // outside of our range, but we have a bailout to handle those cases. |
| 1805 | setRange(GetArrayBufferViewRange(alloc, storageType())); |
| 1806 | } |
| 1807 | |
| 1808 | void MArrayLength::computeRange(TempAllocator& alloc) { |
| 1809 | // Array lengths can go up to UINT32_MAX. We will bail out if the array |
| 1810 | // length > INT32_MAX. |
| 1811 | MOZ_ASSERT(type() == MIRType::Int32)do { static_assert( mozilla::detail::AssertionConditionType< decltype(type() == MIRType::Int32)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(type() == MIRType::Int32))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("type() == MIRType::Int32" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1811); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "type() == MIRType::Int32" ")"); do { MOZ_CrashSequence (__null, 1811); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1812 | setRange(Range::NewUInt32Range(alloc, 0, INT32_MAX(2147483647))); |
| 1813 | } |
| 1814 | |
| 1815 | void MInitializedLength::computeRange(TempAllocator& alloc) { |
| 1816 | setRange( |
| 1817 | Range::NewUInt32Range(alloc, 0, NativeObject::MAX_DENSE_ELEMENTS_COUNT)); |
| 1818 | } |
| 1819 | |
| 1820 | void MArrayBufferViewLength::computeRange(TempAllocator& alloc) { |
| 1821 | if constexpr (ArrayBufferObject::ByteLengthLimit <= INT32_MAX(2147483647)) { |
| 1822 | setRange(Range::NewUInt32Range(alloc, 0, INT32_MAX(2147483647))); |
| 1823 | } |
| 1824 | } |
| 1825 | |
| 1826 | void MArrayBufferViewByteOffset::computeRange(TempAllocator& alloc) { |
| 1827 | if constexpr (ArrayBufferObject::ByteLengthLimit <= INT32_MAX(2147483647)) { |
| 1828 | setRange(Range::NewUInt32Range(alloc, 0, INT32_MAX(2147483647))); |
| 1829 | } |
| 1830 | } |
| 1831 | |
| 1832 | void MResizableTypedArrayLength::computeRange(TempAllocator& alloc) { |
| 1833 | if constexpr (ArrayBufferObject::ByteLengthLimit <= INT32_MAX(2147483647)) { |
| 1834 | setRange(Range::NewUInt32Range(alloc, 0, INT32_MAX(2147483647))); |
| 1835 | } |
| 1836 | } |
| 1837 | |
| 1838 | void MResizableDataViewByteLength::computeRange(TempAllocator& alloc) { |
| 1839 | if constexpr (ArrayBufferObject::ByteLengthLimit <= INT32_MAX(2147483647)) { |
| 1840 | setRange(Range::NewUInt32Range(alloc, 0, INT32_MAX(2147483647))); |
| 1841 | } |
| 1842 | } |
| 1843 | |
| 1844 | void MTypedArrayElementSize::computeRange(TempAllocator& alloc) { |
| 1845 | constexpr auto MaxTypedArraySize = sizeof(double); |
| 1846 | |
| 1847 | #define ASSERT_MAX_SIZE(_, T, N) \ |
| 1848 | static_assert(sizeof(T) <= MaxTypedArraySize, \ |
| 1849 | "unexpected typed array type exceeding 64-bits storage"); |
| 1850 | JS_FOR_EACH_TYPED_ARRAY(ASSERT_MAX_SIZE)ASSERT_MAX_SIZE(int8_t, int8_t, Int8) ASSERT_MAX_SIZE(uint8_t , uint8_t, Uint8) ASSERT_MAX_SIZE(int16_t, int16_t, Int16) ASSERT_MAX_SIZE (uint16_t, uint16_t, Uint16) ASSERT_MAX_SIZE(int32_t, int32_t , Int32) ASSERT_MAX_SIZE(uint32_t, uint32_t, Uint32) ASSERT_MAX_SIZE (float, float, Float32) ASSERT_MAX_SIZE(double, double, Float64 ) ASSERT_MAX_SIZE(uint8_t, js::uint8_clamped, Uint8Clamped) ASSERT_MAX_SIZE (int64_t, int64_t, BigInt64) ASSERT_MAX_SIZE(uint64_t, uint64_t , BigUint64) ASSERT_MAX_SIZE(uint16_t, js::float16, Float16) |
| 1851 | #undef ASSERT_MAX_SIZE |
| 1852 | |
| 1853 | setRange(Range::NewUInt32Range(alloc, 0, MaxTypedArraySize)); |
| 1854 | } |
| 1855 | |
| 1856 | void MStringLength::computeRange(TempAllocator& alloc) { |
| 1857 | static_assert(JSString::MAX_LENGTH <= UINT32_MAX(4294967295U), |
| 1858 | "NewUInt32Range requires a uint32 value"); |
| 1859 | setRange(Range::NewUInt32Range(alloc, 0, JSString::MAX_LENGTH)); |
| 1860 | } |
| 1861 | |
| 1862 | void MArgumentsLength::computeRange(TempAllocator& alloc) { |
| 1863 | // This is is a conservative upper bound on what |TooManyActualArguments| |
| 1864 | // checks. If exceeded, Ion will not be entered in the first place. |
| 1865 | static_assert(ARGS_LENGTH_MAX <= UINT32_MAX(4294967295U), |
| 1866 | "NewUInt32Range requires a uint32 value"); |
| 1867 | setRange(Range::NewUInt32Range(alloc, 0, ARGS_LENGTH_MAX)); |
| 1868 | } |
| 1869 | |
| 1870 | void MBoundsCheck::computeRange(TempAllocator& alloc) { |
| 1871 | // Just transfer the incoming index range to the output. The length() is |
| 1872 | // also interesting, but it is handled as a bailout check, and we're |
| 1873 | // computing a pre-bailout range here. |
| 1874 | setRange(new (alloc) Range(index())); |
| 1875 | } |
| 1876 | |
| 1877 | void MSpectreMaskIndex::computeRange(TempAllocator& alloc) { |
| 1878 | // Just transfer the incoming index range to the output for now. |
| 1879 | setRange(new (alloc) Range(index())); |
| 1880 | } |
| 1881 | |
| 1882 | void MInt32ToIntPtr::computeRange(TempAllocator& alloc) { |
| 1883 | setRange(new (alloc) Range(input())); |
| 1884 | } |
| 1885 | |
| 1886 | void MNonNegativeIntPtrToInt32::computeRange(TempAllocator& alloc) { |
| 1887 | // We will bail out if the IntPtr value > INT32_MAX. |
| 1888 | setRange(Range::NewUInt32Range(alloc, 0, INT32_MAX(2147483647))); |
| 1889 | } |
| 1890 | |
| 1891 | void MArrayPush::computeRange(TempAllocator& alloc) { |
| 1892 | // MArrayPush returns the new array length. It bails out if the new length |
| 1893 | // doesn't fit in an Int32. |
| 1894 | MOZ_ASSERT(type() == MIRType::Int32)do { static_assert( mozilla::detail::AssertionConditionType< decltype(type() == MIRType::Int32)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(type() == MIRType::Int32))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("type() == MIRType::Int32" , "./../../../../js/src/jit/RangeAnalysis.cpp", 1894); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "type() == MIRType::Int32" ")"); do { MOZ_CrashSequence (__null, 1894); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 1895 | setRange(Range::NewUInt32Range(alloc, 0, INT32_MAX(2147483647))); |
| 1896 | } |
| 1897 | |
| 1898 | void MMathFunction::computeRange(TempAllocator& alloc) { |
| 1899 | Range opRange(getOperand(0)); |
| 1900 | switch (function()) { |
| 1901 | case UnaryMathFunction::SinNative: |
| 1902 | case UnaryMathFunction::SinFdlibm: |
| 1903 | case UnaryMathFunction::CosNative: |
| 1904 | case UnaryMathFunction::CosFdlibm: |
| 1905 | if (!opRange.canBeInfiniteOrNaN()) { |
| 1906 | setRange(Range::NewDoubleRange(alloc, -1.0, 1.0)); |
| 1907 | } |
| 1908 | break; |
| 1909 | default: |
| 1910 | break; |
| 1911 | } |
| 1912 | } |
| 1913 | |
| 1914 | void MSign::computeRange(TempAllocator& alloc) { |
| 1915 | Range opRange(getOperand(0)); |
| 1916 | setRange(Range::sign(alloc, &opRange)); |
| 1917 | } |
| 1918 | |
| 1919 | void MRandom::computeRange(TempAllocator& alloc) { |
| 1920 | Range* r = Range::NewDoubleRange(alloc, 0.0, 1.0); |
| 1921 | |
| 1922 | // Random never returns negative zero. |
| 1923 | r->refineToExcludeNegativeZero(); |
| 1924 | |
| 1925 | setRange(r); |
| 1926 | } |
| 1927 | |
| 1928 | void MNaNToZero::computeRange(TempAllocator& alloc) { |
| 1929 | Range other(input()); |
| 1930 | setRange(Range::NaNToZero(alloc, &other)); |
| 1931 | } |
| 1932 | |
| 1933 | /////////////////////////////////////////////////////////////////////////////// |
| 1934 | // Range Analysis |
| 1935 | /////////////////////////////////////////////////////////////////////////////// |
| 1936 | |
| 1937 | static BranchDirection NegateBranchDirection(BranchDirection dir) { |
| 1938 | return (dir == FALSE_BRANCH) ? TRUE_BRANCH : FALSE_BRANCH; |
| 1939 | } |
| 1940 | |
| 1941 | bool RangeAnalysis::analyzeLoop(const MBasicBlock* header) { |
| 1942 | MOZ_ASSERT(header->hasUniqueBackedge())do { static_assert( mozilla::detail::AssertionConditionType< decltype(header->hasUniqueBackedge())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(header->hasUniqueBackedge ()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("header->hasUniqueBackedge()", "./../../../../js/src/jit/RangeAnalysis.cpp" , 1942); AnnotateMozCrashReason("MOZ_ASSERT" "(" "header->hasUniqueBackedge()" ")"); do { MOZ_CrashSequence(__null, 1942); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 1943 | |
| 1944 | // Try to compute an upper bound on the number of times the loop backedge |
| 1945 | // will be taken. Look for tests that dominate the backedge and which have |
| 1946 | // an edge leaving the loop body. |
| 1947 | MBasicBlock* backedge = header->backedge(); |
| 1948 | |
| 1949 | // Ignore trivial infinite loops. |
| 1950 | if (backedge == header) { |
| 1951 | return true; |
| 1952 | } |
| 1953 | |
| 1954 | bool canOsr; |
| 1955 | size_t numBlocks = MarkLoopBlocks(graph_, header, &canOsr); |
| 1956 | |
| 1957 | // Ignore broken loops. |
| 1958 | if (numBlocks == 0) { |
| 1959 | return true; |
| 1960 | } |
| 1961 | |
| 1962 | LoopIterationBound* iterationBound = nullptr; |
| 1963 | |
| 1964 | MBasicBlock* block = backedge; |
| 1965 | do { |
| 1966 | BranchDirection direction; |
| 1967 | MTest* branch = block->immediateDominatorBranch(&direction); |
| 1968 | |
| 1969 | if (block == block->immediateDominator()) { |
| 1970 | break; |
| 1971 | } |
| 1972 | |
| 1973 | block = block->immediateDominator(); |
| 1974 | |
| 1975 | if (branch) { |
| 1976 | direction = NegateBranchDirection(direction); |
| 1977 | MBasicBlock* otherBlock = branch->branchSuccessor(direction); |
| 1978 | if (!otherBlock->isMarked()) { |
| 1979 | if (!alloc().ensureBallast()) { |
| 1980 | return false; |
| 1981 | } |
| 1982 | iterationBound = analyzeLoopIterationCount(header, branch, direction); |
| 1983 | if (iterationBound) { |
| 1984 | break; |
| 1985 | } |
| 1986 | } |
| 1987 | } |
| 1988 | } while (block != header); |
| 1989 | |
| 1990 | if (!iterationBound) { |
| 1991 | UnmarkLoopBlocks(graph_, header); |
| 1992 | return true; |
| 1993 | } |
| 1994 | |
| 1995 | if (!loopIterationBounds.append(iterationBound)) { |
| 1996 | return false; |
| 1997 | } |
| 1998 | |
| 1999 | #ifdef DEBUG1 |
| 2000 | if (JitSpewEnabled(JitSpew_Range)) { |
| 2001 | Sprinter sp(GetJitContext()->cx); |
| 2002 | if (!sp.init()) { |
| 2003 | return false; |
| 2004 | } |
| 2005 | iterationBound->boundSum.dump(sp); |
| 2006 | JS::UniqueChars str = sp.release(); |
| 2007 | if (!str) { |
| 2008 | return false; |
| 2009 | } |
| 2010 | JitSpew(JitSpew_Range, "computed symbolic bound on backedges: %s", |
| 2011 | str.get()); |
| 2012 | } |
| 2013 | #endif |
| 2014 | |
| 2015 | // Try to compute symbolic bounds for the phi nodes at the head of this |
| 2016 | // loop, expressed in terms of the iteration bound just computed. |
| 2017 | |
| 2018 | for (MPhiIterator iter(header->phisBegin()); iter != header->phisEnd(); |
| 2019 | iter++) { |
| 2020 | analyzeLoopPhi(iterationBound, *iter); |
| 2021 | } |
| 2022 | |
| 2023 | // Disallow hoisting for loops that have a generator resume dispatch. This |
| 2024 | // matches jit::LICM. |
| 2025 | if (!mir->compilingWasm() && !mir->outerInfo().hadBoundsCheckBailout() && |
| 2026 | !header->hasGeneratorResumeEntry()) { |
| 2027 | // Try to hoist any bounds checks from the loop using symbolic bounds. |
| 2028 | |
| 2029 | Vector<MBoundsCheck*, 0, JitAllocPolicy> hoistedChecks(alloc()); |
| 2030 | |
| 2031 | for (ReversePostorderIterator iter(graph_.rpoBegin(header)); |
| 2032 | iter != graph_.rpoEnd(); iter++) { |
| 2033 | if (mir->shouldCancel("RangeAnalysis analyzeLoop")) { |
| 2034 | return false; |
| 2035 | } |
| 2036 | |
| 2037 | MBasicBlock* block = *iter; |
| 2038 | if (!block->isMarked()) { |
| 2039 | continue; |
| 2040 | } |
| 2041 | |
| 2042 | for (MDefinitionIterator iter(block); iter; iter++) { |
| 2043 | MDefinition* def = *iter; |
| 2044 | if (def->isBoundsCheck() && def->isMovable()) { |
| 2045 | if (!alloc().ensureBallast()) { |
| 2046 | return false; |
| 2047 | } |
| 2048 | if (tryHoistBoundsCheck(header, def->toBoundsCheck())) { |
| 2049 | if (!hoistedChecks.append(def->toBoundsCheck())) { |
| 2050 | return false; |
| 2051 | } |
| 2052 | } |
| 2053 | } |
| 2054 | } |
| 2055 | } |
| 2056 | |
| 2057 | // Note: replace all uses of the original bounds check with the |
| 2058 | // actual index. This is usually done during bounds check elimination, |
| 2059 | // but in this case it's safe to do it here since the load/store is |
| 2060 | // definitely not loop-invariant, so we will never move it before |
| 2061 | // one of the bounds checks we just added. |
| 2062 | for (size_t i = 0; i < hoistedChecks.length(); i++) { |
| 2063 | MBoundsCheck* ins = hoistedChecks[i]; |
| 2064 | ins->replaceAllUsesWith(ins->index()); |
| 2065 | ins->block()->discard(ins); |
| 2066 | } |
| 2067 | } |
| 2068 | |
| 2069 | UnmarkLoopBlocks(graph_, header); |
| 2070 | return true; |
| 2071 | } |
| 2072 | |
| 2073 | // Unbox beta nodes in order to hoist instruction properly, and not be limited |
| 2074 | // by the beta nodes which are added after each branch. |
| 2075 | static inline MDefinition* DefinitionOrBetaInputDefinition(MDefinition* ins) { |
| 2076 | while (ins->isBeta()) { |
| 2077 | ins = ins->toBeta()->input(); |
| 2078 | } |
| 2079 | return ins; |
| 2080 | } |
| 2081 | |
| 2082 | LoopIterationBound* RangeAnalysis::analyzeLoopIterationCount( |
| 2083 | const MBasicBlock* header, const MTest* test, BranchDirection direction) { |
| 2084 | SimpleLinearSum lhs(nullptr, 0); |
| 2085 | MDefinition* rhs; |
| 2086 | bool lessEqual; |
| 2087 | if (!ExtractLinearInequality(test, direction, &lhs, &rhs, &lessEqual)) { |
| 2088 | return nullptr; |
| 2089 | } |
| 2090 | |
| 2091 | // Ensure the rhs is a loop invariant term. |
| 2092 | if (rhs && rhs->block()->isMarked()) { |
| 2093 | if (lhs.term && lhs.term->block()->isMarked()) { |
| 2094 | return nullptr; |
| 2095 | } |
| 2096 | MDefinition* temp = lhs.term; |
| 2097 | lhs.term = rhs; |
| 2098 | rhs = temp; |
| 2099 | if (!mozilla::SafeSub(0, lhs.constant, &lhs.constant)) { |
| 2100 | return nullptr; |
| 2101 | } |
| 2102 | lessEqual = !lessEqual; |
| 2103 | } |
| 2104 | |
| 2105 | MOZ_ASSERT_IF(rhs, !rhs->block()->isMarked())do { if (rhs) { do { static_assert( mozilla::detail::AssertionConditionType <decltype(!rhs->block()->isMarked())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(!rhs->block()->isMarked ()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("!rhs->block()->isMarked()", "./../../../../js/src/jit/RangeAnalysis.cpp" , 2105); AnnotateMozCrashReason("MOZ_ASSERT" "(" "!rhs->block()->isMarked()" ")"); do { MOZ_CrashSequence(__null, 2105); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); } } while ( false); |
| 2106 | |
| 2107 | // Ensure the lhs is a phi node from the start of the loop body. |
| 2108 | if (!lhs.term || !lhs.term->isPhi() || lhs.term->block() != header) { |
| 2109 | return nullptr; |
| 2110 | } |
| 2111 | |
| 2112 | // Check that the value of the lhs changes by a constant amount with each |
| 2113 | // loop iteration. This requires that the lhs be written in every loop |
| 2114 | // iteration with a value that is a constant difference from its value at |
| 2115 | // the start of the iteration. |
| 2116 | |
| 2117 | if (lhs.term->toPhi()->numOperands() != 2) { |
| 2118 | return nullptr; |
| 2119 | } |
| 2120 | |
| 2121 | // The first operand of the phi should be the lhs' value at the start of |
| 2122 | // the first executed iteration, and not a value written which could |
| 2123 | // replace the second operand below during the middle of execution. |
| 2124 | MDefinition* lhsInitial = lhs.term->toPhi()->getLoopPredecessorOperand(); |
| 2125 | if (lhsInitial->block()->isMarked()) { |
| 2126 | return nullptr; |
| 2127 | } |
| 2128 | |
| 2129 | // The second operand of the phi should be a value written by an add/sub |
| 2130 | // in every loop iteration, i.e. in a block which dominates the backedge. |
| 2131 | MDefinition* lhsWrite = DefinitionOrBetaInputDefinition( |
| 2132 | lhs.term->toPhi()->getLoopBackedgeOperand()); |
| 2133 | if (!lhsWrite->isAdd() && !lhsWrite->isSub()) { |
| 2134 | return nullptr; |
| 2135 | } |
| 2136 | if (!lhsWrite->block()->isMarked()) { |
| 2137 | return nullptr; |
| 2138 | } |
| 2139 | MBasicBlock* bb = header->backedge(); |
| 2140 | for (; bb != lhsWrite->block() && bb != header; |
| 2141 | bb = bb->immediateDominator()) { |
| 2142 | } |
| 2143 | if (bb != lhsWrite->block()) { |
| 2144 | return nullptr; |
| 2145 | } |
| 2146 | |
| 2147 | SimpleLinearSum lhsModified = ExtractLinearSum(lhsWrite); |
| 2148 | |
| 2149 | // Check that the value of the lhs at the backedge is of the form |
| 2150 | // 'old(lhs) + N'. We can be sure that old(lhs) is the value at the start |
| 2151 | // of the iteration, and not that written to lhs in a previous iteration, |
| 2152 | // as such a previous value could not appear directly in the addition: |
| 2153 | // it could not be stored in lhs as the lhs add/sub executes in every |
| 2154 | // iteration, and if it were stored in another variable its use here would |
| 2155 | // be as an operand to a phi node for that variable. |
| 2156 | if (lhsModified.term != lhs.term) { |
| 2157 | return nullptr; |
| 2158 | } |
| 2159 | |
| 2160 | LinearSum iterationBound(alloc()); |
| 2161 | |
| 2162 | if (lhsModified.constant == 1 && !lessEqual) { |
| 2163 | // The value of lhs is 'initial(lhs) + iterCount' and this will end |
| 2164 | // execution of the loop if 'lhs + lhsN >= rhs'. Thus, an upper bound |
| 2165 | // on the number of backedges executed is: |
| 2166 | // |
| 2167 | // initial(lhs) + iterCount + lhsN == rhs |
| 2168 | // iterCount == rhsN - initial(lhs) - lhsN |
| 2169 | |
| 2170 | if (rhs) { |
| 2171 | if (!iterationBound.add(rhs, 1)) { |
| 2172 | return nullptr; |
| 2173 | } |
| 2174 | } |
| 2175 | if (!iterationBound.add(lhsInitial, -1)) { |
| 2176 | return nullptr; |
| 2177 | } |
| 2178 | |
| 2179 | int32_t lhsConstant; |
| 2180 | if (!mozilla::SafeSub(0, lhs.constant, &lhsConstant)) { |
| 2181 | return nullptr; |
| 2182 | } |
| 2183 | if (!iterationBound.add(lhsConstant)) { |
| 2184 | return nullptr; |
| 2185 | } |
| 2186 | } else if (lhsModified.constant == -1 && lessEqual) { |
| 2187 | // The value of lhs is 'initial(lhs) - iterCount'. Similar to the above |
| 2188 | // case, an upper bound on the number of backedges executed is: |
| 2189 | // |
| 2190 | // initial(lhs) - iterCount + lhsN == rhs |
| 2191 | // iterCount == initial(lhs) - rhs + lhsN |
| 2192 | |
| 2193 | if (!iterationBound.add(lhsInitial, 1)) { |
| 2194 | return nullptr; |
| 2195 | } |
| 2196 | if (rhs) { |
| 2197 | if (!iterationBound.add(rhs, -1)) { |
| 2198 | return nullptr; |
| 2199 | } |
| 2200 | } |
| 2201 | if (!iterationBound.add(lhs.constant)) { |
| 2202 | return nullptr; |
| 2203 | } |
| 2204 | } else { |
| 2205 | return nullptr; |
| 2206 | } |
| 2207 | |
| 2208 | return new (alloc()) LoopIterationBound(test, iterationBound); |
| 2209 | } |
| 2210 | |
| 2211 | void RangeAnalysis::analyzeLoopPhi(const LoopIterationBound* loopBound, |
| 2212 | MPhi* phi) { |
| 2213 | // Given a bound on the number of backedges taken, compute an upper and |
| 2214 | // lower bound for a phi node that may change by a constant amount each |
| 2215 | // iteration. Unlike for the case when computing the iteration bound |
| 2216 | // itself, the phi does not need to change the same amount every iteration, |
| 2217 | // but is required to change at most N and be either nondecreasing or |
| 2218 | // nonincreasing. |
| 2219 | |
| 2220 | MOZ_ASSERT(phi->numOperands() == 2)do { static_assert( mozilla::detail::AssertionConditionType< decltype(phi->numOperands() == 2)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(phi->numOperands() == 2)) ), 0))) { do { } while (false); MOZ_ReportAssertionFailure("phi->numOperands() == 2" , "./../../../../js/src/jit/RangeAnalysis.cpp", 2220); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "phi->numOperands() == 2" ")"); do { MOZ_CrashSequence (__null, 2220); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2221 | |
| 2222 | MDefinition* initial = phi->getLoopPredecessorOperand(); |
| 2223 | if (initial->block()->isMarked()) { |
| 2224 | return; |
| 2225 | } |
| 2226 | |
| 2227 | SimpleLinearSum modified = |
| 2228 | ExtractLinearSum(phi->getLoopBackedgeOperand(), MathSpace::Infinite); |
| 2229 | |
| 2230 | if (modified.term != phi || modified.constant == 0) { |
| 2231 | return; |
| 2232 | } |
| 2233 | |
| 2234 | if (!phi->range()) { |
| 2235 | phi->setRange(new (alloc()) Range(phi)); |
| 2236 | } |
| 2237 | |
| 2238 | LinearSum initialSum(alloc()); |
| 2239 | if (!initialSum.add(initial, 1)) { |
| 2240 | return; |
| 2241 | } |
| 2242 | |
| 2243 | // The phi may change by N each iteration, and is either nondecreasing or |
| 2244 | // nonincreasing. initial(phi) is either a lower or upper bound for the |
| 2245 | // phi, and initial(phi) + loopBound * N is either an upper or lower bound, |
| 2246 | // at all points within the loop, provided that loopBound >= 0. |
| 2247 | // |
| 2248 | // We are more interested, however, in the bound for phi at points |
| 2249 | // dominated by the loop bound's test; if the test dominates e.g. a bounds |
| 2250 | // check we want to hoist from the loop, using the value of the phi at the |
| 2251 | // head of the loop for this will usually be too imprecise to hoist the |
| 2252 | // check. These points will execute only if the backedge executes at least |
| 2253 | // one more time (as the test passed and the test dominates the backedge), |
| 2254 | // so we know both that loopBound >= 1 and that the phi's value has changed |
| 2255 | // at most loopBound - 1 times. Thus, another upper or lower bound for the |
| 2256 | // phi is initial(phi) + (loopBound - 1) * N, without requiring us to |
| 2257 | // ensure that loopBound >= 0. |
| 2258 | |
| 2259 | LinearSum limitSum(loopBound->boundSum); |
| 2260 | if (!limitSum.multiply(modified.constant) || !limitSum.add(initialSum)) { |
| 2261 | return; |
| 2262 | } |
| 2263 | |
| 2264 | int32_t negativeConstant; |
| 2265 | if (!mozilla::SafeSub(0, modified.constant, &negativeConstant) || |
| 2266 | !limitSum.add(negativeConstant)) { |
| 2267 | return; |
| 2268 | } |
| 2269 | |
| 2270 | Range initRange(initial); |
| 2271 | if (modified.constant > 0) { |
| 2272 | if (initRange.hasInt32LowerBound()) { |
| 2273 | phi->range()->refineLower(initRange.lower()); |
| 2274 | } |
| 2275 | phi->range()->setSymbolicLower( |
| 2276 | SymbolicBound::New(alloc(), nullptr, initialSum)); |
| 2277 | phi->range()->setSymbolicUpper( |
| 2278 | SymbolicBound::New(alloc(), loopBound, limitSum)); |
| 2279 | } else { |
| 2280 | if (initRange.hasInt32UpperBound()) { |
| 2281 | phi->range()->refineUpper(initRange.upper()); |
| 2282 | } |
| 2283 | phi->range()->setSymbolicUpper( |
| 2284 | SymbolicBound::New(alloc(), nullptr, initialSum)); |
| 2285 | phi->range()->setSymbolicLower( |
| 2286 | SymbolicBound::New(alloc(), loopBound, limitSum)); |
| 2287 | } |
| 2288 | |
| 2289 | JitSpew(JitSpew_Range, "added symbolic range on %u", phi->id()); |
| 2290 | SpewRange(phi); |
| 2291 | } |
| 2292 | |
| 2293 | // Whether bound is valid at the specified bounds check instruction in a loop, |
| 2294 | // and may be used to hoist ins. |
| 2295 | static inline bool SymbolicBoundIsValid(const MBasicBlock* header, |
| 2296 | const MBoundsCheck* ins, |
| 2297 | const SymbolicBound* bound) { |
| 2298 | if (!bound->loop) { |
| 2299 | return true; |
| 2300 | } |
| 2301 | if (ins->block() == header) { |
| 2302 | return false; |
| 2303 | } |
| 2304 | MBasicBlock* bb = ins->block()->immediateDominator(); |
| 2305 | while (bb != header && bb != bound->loop->test->block()) { |
| 2306 | bb = bb->immediateDominator(); |
| 2307 | } |
| 2308 | return bb == bound->loop->test->block(); |
| 2309 | } |
| 2310 | |
| 2311 | bool RangeAnalysis::tryHoistBoundsCheck(const MBasicBlock* header, |
| 2312 | const MBoundsCheck* ins) { |
| 2313 | // The bounds check's length must be loop invariant or a constant. |
| 2314 | MDefinition* length = DefinitionOrBetaInputDefinition(ins->length()); |
| 2315 | if (length->block()->isMarked() && !length->isConstant()) { |
| 2316 | return false; |
| 2317 | } |
| 2318 | |
| 2319 | // The bounds check's index should not be loop invariant (else we would |
| 2320 | // already have hoisted it during LICM). |
| 2321 | SimpleLinearSum index = ExtractLinearSum(ins->index()); |
| 2322 | if (!index.term || !index.term->block()->isMarked()) { |
| 2323 | return false; |
| 2324 | } |
| 2325 | |
| 2326 | // Check for a symbolic lower and upper bound on the index. If either |
| 2327 | // condition depends on an iteration bound for the loop, only hoist if |
| 2328 | // the bounds check is dominated by the iteration bound's test. |
| 2329 | if (!index.term->range()) { |
| 2330 | return false; |
| 2331 | } |
| 2332 | const SymbolicBound* lower = index.term->range()->symbolicLower(); |
| 2333 | if (!lower || !SymbolicBoundIsValid(header, ins, lower)) { |
| 2334 | return false; |
| 2335 | } |
| 2336 | const SymbolicBound* upper = index.term->range()->symbolicUpper(); |
| 2337 | if (!upper || !SymbolicBoundIsValid(header, ins, upper)) { |
| 2338 | return false; |
| 2339 | } |
| 2340 | |
| 2341 | MBasicBlock* preLoop = header->loopPredecessor(); |
| 2342 | MOZ_ASSERT(!preLoop->isMarked())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!preLoop->isMarked())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(!preLoop->isMarked()))), 0 ))) { do { } while (false); MOZ_ReportAssertionFailure("!preLoop->isMarked()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 2342); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "!preLoop->isMarked()" ")"); do { MOZ_CrashSequence (__null, 2342); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2343 | |
| 2344 | MDefinition* lowerTerm = ConvertLinearSum(alloc(), preLoop, lower->sum, |
| 2345 | BailoutKind::HoistBoundsCheck); |
| 2346 | if (!lowerTerm) { |
| 2347 | return false; |
| 2348 | } |
| 2349 | |
| 2350 | MDefinition* upperTerm = ConvertLinearSum(alloc(), preLoop, upper->sum, |
| 2351 | BailoutKind::HoistBoundsCheck); |
| 2352 | if (!upperTerm) { |
| 2353 | return false; |
| 2354 | } |
| 2355 | |
| 2356 | // We are checking that index + indexConstant >= 0, and know that |
| 2357 | // index >= lowerTerm + lowerConstant. Thus, check that: |
| 2358 | // |
| 2359 | // lowerTerm + lowerConstant + indexConstant >= 0 |
| 2360 | // lowerTerm >= -lowerConstant - indexConstant |
| 2361 | |
| 2362 | int32_t lowerConstant = 0; |
| 2363 | if (!mozilla::SafeSub(lowerConstant, index.constant, &lowerConstant)) { |
| 2364 | return false; |
| 2365 | } |
| 2366 | if (!mozilla::SafeSub(lowerConstant, lower->sum.constant(), &lowerConstant)) { |
| 2367 | return false; |
| 2368 | } |
| 2369 | |
| 2370 | // We are checking that index < boundsLength, and know that |
| 2371 | // index <= upperTerm + upperConstant. Thus, check that: |
| 2372 | // |
| 2373 | // upperTerm + upperConstant < boundsLength |
| 2374 | |
| 2375 | int32_t upperConstant = index.constant; |
| 2376 | if (!mozilla::SafeAdd(upper->sum.constant(), upperConstant, &upperConstant)) { |
| 2377 | return false; |
| 2378 | } |
| 2379 | |
| 2380 | // Hoist the loop invariant lower bounds checks. |
| 2381 | MBoundsCheckLower* lowerCheck = MBoundsCheckLower::New(alloc(), lowerTerm); |
| 2382 | lowerCheck->setMinimum(lowerConstant); |
| 2383 | lowerCheck->computeRange(alloc()); |
| 2384 | lowerCheck->collectRangeInfoPreTrunc(); |
| 2385 | lowerCheck->setBailoutKind(BailoutKind::HoistBoundsCheck); |
| 2386 | preLoop->insertBefore(preLoop->lastIns(), lowerCheck); |
| 2387 | |
| 2388 | // A common pattern for iterating over typed arrays is this: |
| 2389 | // |
| 2390 | // for (var i = 0; i < ta.length; i++) { |
| 2391 | // use ta[i]; |
| 2392 | // } |
| 2393 | // |
| 2394 | // Here |upperTerm| (= ta.length) is a NonNegativeIntPtrToInt32 instruction. |
| 2395 | // Unwrap this if |length| is also an IntPtr so that we don't add an |
| 2396 | // unnecessary bounds check and Int32ToIntPtr below. |
| 2397 | if (upperTerm->isNonNegativeIntPtrToInt32() && |
| 2398 | length->type() == MIRType::IntPtr) { |
| 2399 | upperTerm = upperTerm->toNonNegativeIntPtrToInt32()->input(); |
| 2400 | } |
| 2401 | |
| 2402 | // Hoist the loop invariant upper bounds checks. |
| 2403 | if (upperTerm != length || upperConstant >= 0) { |
| 2404 | // Hoist the bound check's length if it isn't already loop invariant. |
| 2405 | if (length->block()->isMarked()) { |
| 2406 | MOZ_ASSERT(length->isConstant())do { static_assert( mozilla::detail::AssertionConditionType< decltype(length->isConstant())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(length->isConstant()))), 0 ))) { do { } while (false); MOZ_ReportAssertionFailure("length->isConstant()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 2406); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "length->isConstant()" ")"); do { MOZ_CrashSequence (__null, 2406); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2407 | MInstruction* lengthIns = length->toInstruction(); |
| 2408 | lengthIns->block()->moveBefore(preLoop->lastIns(), lengthIns); |
| 2409 | } |
| 2410 | |
| 2411 | // If the length is IntPtr, convert the upperTerm to that as well for the |
| 2412 | // bounds check. |
| 2413 | if (length->type() == MIRType::IntPtr && |
| 2414 | upperTerm->type() == MIRType::Int32) { |
| 2415 | upperTerm = MInt32ToIntPtr::New(alloc(), upperTerm); |
| 2416 | upperTerm->computeRange(alloc()); |
| 2417 | upperTerm->collectRangeInfoPreTrunc(); |
| 2418 | preLoop->insertBefore(preLoop->lastIns(), upperTerm->toInstruction()); |
| 2419 | } |
| 2420 | |
| 2421 | MBoundsCheck* upperCheck = MBoundsCheck::New(alloc(), upperTerm, length); |
| 2422 | upperCheck->setMinimum(upperConstant); |
| 2423 | upperCheck->setMaximum(upperConstant); |
| 2424 | upperCheck->computeRange(alloc()); |
| 2425 | upperCheck->collectRangeInfoPreTrunc(); |
| 2426 | upperCheck->setBailoutKind(BailoutKind::HoistBoundsCheck); |
| 2427 | preLoop->insertBefore(preLoop->lastIns(), upperCheck); |
| 2428 | } |
| 2429 | |
| 2430 | return true; |
| 2431 | } |
| 2432 | |
| 2433 | bool RangeAnalysis::analyze() { |
| 2434 | JitSpew(JitSpew_Range, "Doing range propagation"); |
| 2435 | |
| 2436 | for (ReversePostorderIterator iter(graph_.rpoBegin()); |
| 2437 | iter != graph_.rpoEnd(); iter++) { |
| 2438 | if (mir->shouldCancel("RangeAnalysis analyze")) { |
| 2439 | return false; |
| 2440 | } |
| 2441 | |
| 2442 | MBasicBlock* block = *iter; |
| 2443 | // No blocks are supposed to be unreachable, except when we have an OSR |
| 2444 | // block, in which case the Value Numbering phase add fixup blocks which |
| 2445 | // are unreachable. |
| 2446 | MOZ_ASSERT(!block->unreachable() || graph_.osrBlock())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!block->unreachable() || graph_.osrBlock())>:: isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(!block->unreachable() || graph_.osrBlock()))), 0) )) { do { } while (false); MOZ_ReportAssertionFailure("!block->unreachable() || graph_.osrBlock()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 2446); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "!block->unreachable() || graph_.osrBlock()" ")"); do { MOZ_CrashSequence(__null, 2446); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 2447 | |
| 2448 | // If the block's immediate dominator is unreachable, the block is |
| 2449 | // unreachable. Iterating in RPO, we'll always see the immediate |
| 2450 | // dominator before the block. |
| 2451 | if (block->immediateDominator()->unreachable()) { |
| 2452 | block->setUnreachableUnchecked(); |
| 2453 | continue; |
| 2454 | } |
| 2455 | |
| 2456 | for (MDefinitionIterator iter(block); iter; iter++) { |
| 2457 | MDefinition* def = *iter; |
| 2458 | if (!alloc().ensureBallast()) { |
| 2459 | return false; |
| 2460 | } |
| 2461 | |
| 2462 | def->computeRange(alloc()); |
| 2463 | JitSpew(JitSpew_Range, "computing range on %u", def->id()); |
| 2464 | SpewRange(def); |
| 2465 | } |
| 2466 | |
| 2467 | // Beta node range analysis may have marked this block unreachable. If |
| 2468 | // so, it's no longer interesting to continue processing it. |
| 2469 | if (block->unreachable()) { |
| 2470 | continue; |
| 2471 | } |
| 2472 | |
| 2473 | if (block->isLoopHeader()) { |
| 2474 | if (!analyzeLoop(block)) { |
| 2475 | return false; |
| 2476 | } |
| 2477 | } |
| 2478 | |
| 2479 | // First pass at collecting range info - while the beta nodes are still |
| 2480 | // around and before truncation. |
| 2481 | for (MInstructionIterator iter(block->begin()); iter != block->end(); |
| 2482 | iter++) { |
| 2483 | iter->collectRangeInfoPreTrunc(); |
| 2484 | } |
| 2485 | } |
| 2486 | |
| 2487 | return true; |
| 2488 | } |
| 2489 | |
| 2490 | bool RangeAnalysis::addRangeAssertions() { |
| 2491 | if (!JitOptions.checkRangeAnalysis) { |
| 2492 | return true; |
| 2493 | } |
| 2494 | |
| 2495 | // Check the computed range for this instruction, if the option is set. Note |
| 2496 | // that this code is quite invasive; it adds numerous additional |
| 2497 | // instructions for each MInstruction with a computed range, and it uses |
| 2498 | // registers, so it also affects register allocation. |
| 2499 | for (ReversePostorderIterator iter(graph_.rpoBegin()); |
| 2500 | iter != graph_.rpoEnd(); iter++) { |
| 2501 | MBasicBlock* block = *iter; |
| 2502 | |
| 2503 | // Do not add assertions in unreachable blocks. |
| 2504 | if (block->unreachable()) { |
| 2505 | continue; |
| 2506 | } |
| 2507 | |
| 2508 | for (MDefinitionIterator iter(block); iter; iter++) { |
| 2509 | MDefinition* ins = *iter; |
| 2510 | |
| 2511 | // Perform range checking for all numeric and numeric-like types. |
| 2512 | if (!IsNumberType(ins->type()) && ins->type() != MIRType::Boolean && |
| 2513 | ins->type() != MIRType::Value) { |
| 2514 | continue; |
| 2515 | } |
| 2516 | |
| 2517 | // MIsNoIter is fused with the MTest that follows it and emitted as |
| 2518 | // LIsNoIterAndBranch. Similarly, MIteratorHasIndices is fused to |
| 2519 | // become LIteratorHasIndicesAndBranch and IteratorsMatchAndHaveIndices |
| 2520 | // becomes LIteratorsMatchAndHaveIndicesAndBranch. Skip them to avoid |
| 2521 | // complicating lowering. |
| 2522 | if (ins->isIsNoIter() || ins->isIteratorHasIndices() || |
| 2523 | ins->isIteratorsMatchAndHaveIndices()) { |
| 2524 | MOZ_ASSERT(ins->hasOneUse())do { static_assert( mozilla::detail::AssertionConditionType< decltype(ins->hasOneUse())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(ins->hasOneUse()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("ins->hasOneUse()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 2524); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "ins->hasOneUse()" ")"); do { MOZ_CrashSequence (__null, 2524); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2525 | continue; |
| 2526 | } |
| 2527 | |
| 2528 | Range r(ins); |
| 2529 | |
| 2530 | MOZ_ASSERT_IF(ins->type() == MIRType::Int64, r.isUnknown())do { if (ins->type() == MIRType::Int64) { do { static_assert ( mozilla::detail::AssertionConditionType<decltype(r.isUnknown ())>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(r.isUnknown()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("r.isUnknown()", "./../../../../js/src/jit/RangeAnalysis.cpp" , 2530); AnnotateMozCrashReason("MOZ_ASSERT" "(" "r.isUnknown()" ")"); do { MOZ_CrashSequence(__null, 2530); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); } } while ( false); |
| 2531 | |
| 2532 | // Don't insert assertions if there's nothing interesting to assert. |
| 2533 | if (r.isUnknown() || |
| 2534 | (ins->type() == MIRType::Int32 && r.isUnknownInt32())) { |
| 2535 | continue; |
| 2536 | } |
| 2537 | |
| 2538 | // Don't add a use to an instruction that is recovered on bailout. |
| 2539 | if (ins->isRecoveredOnBailout()) { |
| 2540 | continue; |
| 2541 | } |
| 2542 | |
| 2543 | if (!alloc().ensureBallast()) { |
| 2544 | return false; |
| 2545 | } |
| 2546 | MAssertRange* guard = |
| 2547 | MAssertRange::New(alloc(), ins, new (alloc()) Range(r)); |
| 2548 | |
| 2549 | // Beta nodes and interrupt checks are required to be located at the |
| 2550 | // beginnings of basic blocks, so we must insert range assertions |
| 2551 | // after any such instructions. |
| 2552 | MInstruction* insertAt = nullptr; |
| 2553 | if (block->graph().osrBlock() == block) { |
| 2554 | insertAt = ins->toInstruction(); |
| 2555 | } else { |
| 2556 | insertAt = block->safeInsertTop(ins); |
| 2557 | } |
| 2558 | |
| 2559 | if (insertAt == *iter) { |
| 2560 | block->insertAfter(insertAt, guard); |
| 2561 | } else { |
| 2562 | block->insertBefore(insertAt, guard); |
| 2563 | } |
| 2564 | } |
| 2565 | } |
| 2566 | |
| 2567 | return true; |
| 2568 | } |
| 2569 | |
| 2570 | /////////////////////////////////////////////////////////////////////////////// |
| 2571 | // Range based Truncation |
| 2572 | /////////////////////////////////////////////////////////////////////////////// |
| 2573 | |
| 2574 | void Range::clampToInt32() { |
| 2575 | if (isInt32()) { |
| 2576 | return; |
| 2577 | } |
| 2578 | int32_t l = hasInt32LowerBound() ? lower() : JSVAL_INT_MIN((int32_t)0x80000000); |
| 2579 | int32_t h = hasInt32UpperBound() ? upper() : JSVAL_INT_MAX((int32_t)0x7fffffff); |
| 2580 | setInt32(l, h); |
| 2581 | } |
| 2582 | |
| 2583 | void Range::wrapAroundToInt32() { |
| 2584 | if (!hasInt32Bounds()) { |
| 2585 | setInt32(JSVAL_INT_MIN((int32_t)0x80000000), JSVAL_INT_MAX((int32_t)0x7fffffff)); |
| 2586 | } else if (canHaveFractionalPart()) { |
| 2587 | // Clearing the fractional field may provide an opportunity to refine |
| 2588 | // lower_ or upper_. |
| 2589 | canHaveFractionalPart_ = ExcludesFractionalParts; |
| 2590 | canBeNegativeZero_ = ExcludesNegativeZero; |
| 2591 | refineInt32BoundsByExponent(max_exponent_, &lower_, &hasInt32LowerBound_, |
| 2592 | &upper_, &hasInt32UpperBound_); |
| 2593 | |
| 2594 | assertInvariants(); |
| 2595 | } else { |
| 2596 | // If nothing else, we can clear the negative zero flag. |
| 2597 | canBeNegativeZero_ = ExcludesNegativeZero; |
| 2598 | } |
| 2599 | MOZ_ASSERT(isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isInt32()", "./../../../../js/src/jit/RangeAnalysis.cpp" , 2599); AnnotateMozCrashReason("MOZ_ASSERT" "(" "isInt32()" ")" ); do { MOZ_CrashSequence(__null, 2599); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 2600 | } |
| 2601 | |
| 2602 | void Range::wrapAroundToShiftCount() { |
| 2603 | wrapAroundToInt32(); |
| 2604 | if (lower() < 0 || upper() >= 32) { |
| 2605 | setInt32(0, 31); |
| 2606 | } |
| 2607 | } |
| 2608 | |
| 2609 | void Range::wrapAroundToBoolean() { |
| 2610 | wrapAroundToInt32(); |
| 2611 | if (!isBoolean()) { |
| 2612 | setInt32(0, 1); |
| 2613 | } |
| 2614 | MOZ_ASSERT(isBoolean())do { static_assert( mozilla::detail::AssertionConditionType< decltype(isBoolean())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(isBoolean()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isBoolean()", "./../../../../js/src/jit/RangeAnalysis.cpp" , 2614); AnnotateMozCrashReason("MOZ_ASSERT" "(" "isBoolean()" ")"); do { MOZ_CrashSequence(__null, 2614); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 2615 | } |
| 2616 | |
| 2617 | bool MDefinition::canTruncate() const { |
| 2618 | // No procedure defined for truncating this instruction. |
| 2619 | return false; |
| 2620 | } |
| 2621 | |
| 2622 | void MDefinition::truncate(TruncateKind kind) { |
| 2623 | MOZ_CRASH("No procedure defined for truncating this instruction.")do { do { } while (false); MOZ_ReportCrash("" "No procedure defined for truncating this instruction." , "./../../../../js/src/jit/RangeAnalysis.cpp", 2623); AnnotateMozCrashReason ("MOZ_CRASH(" "No procedure defined for truncating this instruction." ")"); do { MOZ_CrashSequence(__null, 2623); __attribute__((nomerge )) ::abort(); } while (false); } while (false); |
| 2624 | } |
| 2625 | |
| 2626 | bool MConstant::canTruncate() const { return IsFloatingPointType(type()); } |
| 2627 | |
| 2628 | void MConstant::truncate(TruncateKind kind) { |
| 2629 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2629); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2629); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2630 | |
| 2631 | // Truncate the double to int, since all uses truncates it. |
| 2632 | int32_t res = ToInt32(numberToDouble()); |
| 2633 | payload_.asBits = 0; |
| 2634 | payload_.i32 = res; |
| 2635 | setResultType(MIRType::Int32); |
| 2636 | if (range()) { |
| 2637 | range()->setInt32(res, res); |
| 2638 | } |
| 2639 | } |
| 2640 | |
| 2641 | bool MPhi::canTruncate() const { |
| 2642 | return type() == MIRType::Double || type() == MIRType::Int32; |
| 2643 | } |
| 2644 | |
| 2645 | void MPhi::truncate(TruncateKind kind) { |
| 2646 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2646); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2646); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2647 | truncateKind_ = kind; |
| 2648 | setResultType(MIRType::Int32); |
| 2649 | if (kind >= TruncateKind::IndirectTruncate && range()) { |
| 2650 | range()->wrapAroundToInt32(); |
| 2651 | } |
| 2652 | } |
| 2653 | |
| 2654 | bool MAdd::canTruncate() const { |
| 2655 | return type() == MIRType::Double || type() == MIRType::Int32; |
| 2656 | } |
| 2657 | |
| 2658 | void MAdd::truncate(TruncateKind kind) { |
| 2659 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2659); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2659); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2660 | |
| 2661 | // Remember analysis, needed for fallible checks. |
| 2662 | setTruncateKind(kind); |
| 2663 | |
| 2664 | setSpecialization(MIRType::Int32); |
| 2665 | if (truncateKind() >= TruncateKind::IndirectTruncate && range()) { |
| 2666 | range()->wrapAroundToInt32(); |
| 2667 | } |
| 2668 | } |
| 2669 | |
| 2670 | bool MSub::canTruncate() const { |
| 2671 | return type() == MIRType::Double || type() == MIRType::Int32; |
| 2672 | } |
| 2673 | |
| 2674 | void MSub::truncate(TruncateKind kind) { |
| 2675 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2675); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2675); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2676 | |
| 2677 | // Remember analysis, needed for fallible checks. |
| 2678 | setTruncateKind(kind); |
| 2679 | setSpecialization(MIRType::Int32); |
| 2680 | if (truncateKind() >= TruncateKind::IndirectTruncate && range()) { |
| 2681 | range()->wrapAroundToInt32(); |
| 2682 | } |
| 2683 | } |
| 2684 | |
| 2685 | bool MMul::canTruncate() const { |
| 2686 | return type() == MIRType::Double || type() == MIRType::Int32; |
| 2687 | } |
| 2688 | |
| 2689 | void MMul::truncate(TruncateKind kind) { |
| 2690 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2690); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2690); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2691 | |
| 2692 | // Remember analysis, needed for fallible checks. |
| 2693 | setTruncateKind(kind); |
| 2694 | setSpecialization(MIRType::Int32); |
| 2695 | if (truncateKind() >= TruncateKind::IndirectTruncate) { |
| 2696 | setCanBeNegativeZero(false); |
| 2697 | if (range()) { |
| 2698 | range()->wrapAroundToInt32(); |
| 2699 | } |
| 2700 | } |
| 2701 | } |
| 2702 | |
| 2703 | bool MDiv::canTruncate() const { |
| 2704 | return type() == MIRType::Double || type() == MIRType::Int32; |
| 2705 | } |
| 2706 | |
| 2707 | void MDiv::truncate(TruncateKind kind) { |
| 2708 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2708); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2708); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2709 | |
| 2710 | // Remember analysis, needed for fallible checks. |
| 2711 | setTruncateKind(kind); |
| 2712 | setSpecialization(MIRType::Int32); |
| 2713 | |
| 2714 | // Divisions where the lhs and rhs are unsigned and the result is |
| 2715 | // truncated can be lowered more efficiently. |
| 2716 | if (unsignedOperands()) { |
| 2717 | replaceWithUnsignedOperands(); |
| 2718 | unsigned_ = true; |
| 2719 | } |
| 2720 | } |
| 2721 | |
| 2722 | bool MMod::canTruncate() const { |
| 2723 | return type() == MIRType::Double || type() == MIRType::Int32; |
| 2724 | } |
| 2725 | |
| 2726 | void MMod::truncate(TruncateKind kind) { |
| 2727 | // As for division, handle unsigned modulus with a truncated result. |
| 2728 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2728); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2728); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2729 | |
| 2730 | // Remember analysis, needed for fallible checks. |
| 2731 | setTruncateKind(kind); |
| 2732 | setSpecialization(MIRType::Int32); |
| 2733 | |
| 2734 | if (unsignedOperands()) { |
| 2735 | replaceWithUnsignedOperands(); |
| 2736 | unsigned_ = true; |
| 2737 | } |
| 2738 | } |
| 2739 | |
| 2740 | bool MToDouble::canTruncate() const { |
| 2741 | MOZ_ASSERT(type() == MIRType::Double)do { static_assert( mozilla::detail::AssertionConditionType< decltype(type() == MIRType::Double)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(type() == MIRType::Double))) , 0))) { do { } while (false); MOZ_ReportAssertionFailure("type() == MIRType::Double" , "./../../../../js/src/jit/RangeAnalysis.cpp", 2741); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "type() == MIRType::Double" ")"); do { MOZ_CrashSequence (__null, 2741); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2742 | return true; |
| 2743 | } |
| 2744 | |
| 2745 | void MToDouble::truncate(TruncateKind kind) { |
| 2746 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2746); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2746); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2747 | setTruncateKind(kind); |
| 2748 | |
| 2749 | // We use the return type to flag that this MToDouble should be replaced by |
| 2750 | // a MTruncateToInt32 when modifying the graph. |
| 2751 | setResultType(MIRType::Int32); |
| 2752 | if (truncateKind() >= TruncateKind::IndirectTruncate) { |
| 2753 | if (range()) { |
| 2754 | range()->wrapAroundToInt32(); |
| 2755 | } |
| 2756 | } |
| 2757 | } |
| 2758 | |
| 2759 | bool MLimitedTruncate::canTruncate() const { return true; } |
| 2760 | |
| 2761 | void MLimitedTruncate::truncate(TruncateKind kind) { |
| 2762 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2762); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2762); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2763 | setTruncateKind(kind); |
| 2764 | setResultType(MIRType::Int32); |
| 2765 | if (kind >= TruncateKind::IndirectTruncate && range()) { |
| 2766 | range()->wrapAroundToInt32(); |
| 2767 | } |
| 2768 | } |
| 2769 | |
| 2770 | bool MCompare::canTruncate() const { |
| 2771 | if (!isDoubleComparison()) { |
| 2772 | return false; |
| 2773 | } |
| 2774 | |
| 2775 | // If both operands are naturally in the int32 range, we can convert from |
| 2776 | // a double comparison to being an int32 comparison. |
| 2777 | if (!Range(lhs()).isInt32() || !Range(rhs()).isInt32()) { |
| 2778 | return false; |
| 2779 | } |
| 2780 | |
| 2781 | return true; |
| 2782 | } |
| 2783 | |
| 2784 | void MCompare::truncate(TruncateKind kind) { |
| 2785 | MOZ_ASSERT(canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(canTruncate()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("canTruncate()", "./../../../../js/src/jit/RangeAnalysis.cpp", 2785); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "canTruncate()" ")"); do { MOZ_CrashSequence (__null, 2785); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2786 | compareType_ = Compare_Int32; |
| 2787 | |
| 2788 | // Truncating the operands won't change their value because we don't force a |
| 2789 | // truncation, but it will change their type, which we need because we |
| 2790 | // now expect integer inputs. |
| 2791 | truncateOperands_ = true; |
| 2792 | } |
| 2793 | |
| 2794 | TruncateKind MDefinition::operandTruncateKind(size_t index) const { |
| 2795 | // Generic routine: We don't know anything. |
| 2796 | return TruncateKind::NoTruncate; |
| 2797 | } |
| 2798 | |
| 2799 | TruncateKind MPhi::operandTruncateKind(size_t index) const { |
| 2800 | // The truncation applied to a phi is effectively applied to the phi's |
| 2801 | // operands. |
| 2802 | return truncateKind_; |
| 2803 | } |
| 2804 | |
| 2805 | TruncateKind MTruncateToInt32::operandTruncateKind(size_t index) const { |
| 2806 | // This operator is an explicit truncate to int32. |
| 2807 | return TruncateKind::Truncate; |
| 2808 | } |
| 2809 | |
| 2810 | TruncateKind MBinaryBitwiseInstruction::operandTruncateKind( |
| 2811 | size_t index) const { |
| 2812 | // The bitwise operators truncate to int32. |
| 2813 | return TruncateKind::Truncate; |
| 2814 | } |
| 2815 | |
| 2816 | TruncateKind MLimitedTruncate::operandTruncateKind(size_t index) const { |
| 2817 | return std::min(truncateKind(), truncateLimit_); |
| 2818 | } |
| 2819 | |
| 2820 | TruncateKind MAdd::operandTruncateKind(size_t index) const { |
| 2821 | // This operator is doing some arithmetic. If its result is truncated, |
| 2822 | // it's an indirect truncate for its operands. |
| 2823 | return std::min(truncateKind(), TruncateKind::IndirectTruncate); |
| 2824 | } |
| 2825 | |
| 2826 | TruncateKind MSub::operandTruncateKind(size_t index) const { |
| 2827 | // See the comment in MAdd::operandTruncateKind. |
| 2828 | return std::min(truncateKind(), TruncateKind::IndirectTruncate); |
| 2829 | } |
| 2830 | |
| 2831 | TruncateKind MMul::operandTruncateKind(size_t index) const { |
| 2832 | // See the comment in MAdd::operandTruncateKind. |
| 2833 | return std::min(truncateKind(), TruncateKind::IndirectTruncate); |
| 2834 | } |
| 2835 | |
| 2836 | TruncateKind MToDouble::operandTruncateKind(size_t index) const { |
| 2837 | // MToDouble propagates its truncate kind to its operand. |
| 2838 | return truncateKind(); |
| 2839 | } |
| 2840 | |
| 2841 | TruncateKind MStoreUnboxedScalar::operandTruncateKind(size_t index) const { |
| 2842 | // An integer store truncates the stored value. |
| 2843 | return (index == 2 && isIntegerWrite()) ? TruncateKind::Truncate |
| 2844 | : TruncateKind::NoTruncate; |
| 2845 | } |
| 2846 | |
| 2847 | TruncateKind MStoreDataViewElement::operandTruncateKind(size_t index) const { |
| 2848 | // An integer store truncates the stored value. |
| 2849 | return (index == 2 && isIntegerWrite()) ? TruncateKind::Truncate |
| 2850 | : TruncateKind::NoTruncate; |
| 2851 | } |
| 2852 | |
| 2853 | TruncateKind MStoreTypedArrayElementHole::operandTruncateKind( |
| 2854 | size_t index) const { |
| 2855 | // An integer store truncates the stored value. |
| 2856 | return (index == 3 && isIntegerWrite()) ? TruncateKind::Truncate |
| 2857 | : TruncateKind::NoTruncate; |
| 2858 | } |
| 2859 | |
| 2860 | TruncateKind MTypedArrayFill::operandTruncateKind(size_t index) const { |
| 2861 | // An integer store truncates the stored value. |
| 2862 | return (index == 1 && isIntegerWrite()) ? TruncateKind::Truncate |
| 2863 | : TruncateKind::NoTruncate; |
| 2864 | } |
| 2865 | |
| 2866 | TruncateKind MDiv::operandTruncateKind(size_t index) const { |
| 2867 | return std::min(truncateKind(), TruncateKind::TruncateAfterBailouts); |
| 2868 | } |
| 2869 | |
| 2870 | TruncateKind MMod::operandTruncateKind(size_t index) const { |
| 2871 | return std::min(truncateKind(), TruncateKind::TruncateAfterBailouts); |
| 2872 | } |
| 2873 | |
| 2874 | TruncateKind MCompare::operandTruncateKind(size_t index) const { |
| 2875 | // If we're doing an int32 comparison on operands which were previously |
| 2876 | // floating-point, convert them! |
| 2877 | MOZ_ASSERT_IF(truncateOperands_, isInt32Comparison())do { if (truncateOperands_) { do { static_assert( mozilla::detail ::AssertionConditionType<decltype(isInt32Comparison())> ::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(isInt32Comparison()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("isInt32Comparison()", "./../../../../js/src/jit/RangeAnalysis.cpp" , 2877); AnnotateMozCrashReason("MOZ_ASSERT" "(" "isInt32Comparison()" ")"); do { MOZ_CrashSequence(__null, 2877); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); } } while ( false); |
| 2878 | return truncateOperands_ ? TruncateKind::TruncateAfterBailouts |
| 2879 | : TruncateKind::NoTruncate; |
| 2880 | } |
| 2881 | |
| 2882 | static bool TruncateTest(TempAllocator& alloc, const MTest* test) { |
| 2883 | // If all possible inputs to the test are either int32 or boolean, |
| 2884 | // convert those inputs to int32 so that an int32 test can be performed. |
| 2885 | |
| 2886 | if (test->input()->type() != MIRType::Value) { |
| 2887 | return true; |
| 2888 | } |
| 2889 | |
| 2890 | if (!test->input()->isPhi() || !test->input()->hasOneDefUse() || |
| 2891 | test->input()->isImplicitlyUsed()) { |
| 2892 | return true; |
| 2893 | } |
| 2894 | |
| 2895 | MPhi* phi = test->input()->toPhi(); |
| 2896 | for (size_t i = 0; i < phi->numOperands(); i++) { |
| 2897 | MDefinition* def = phi->getOperand(i); |
| 2898 | if (!def->isBox()) { |
| 2899 | return true; |
| 2900 | } |
| 2901 | MDefinition* inner = def->getOperand(0); |
| 2902 | if (inner->type() != MIRType::Boolean && inner->type() != MIRType::Int32) { |
| 2903 | return true; |
| 2904 | } |
| 2905 | } |
| 2906 | |
| 2907 | for (size_t i = 0; i < phi->numOperands(); i++) { |
| 2908 | MDefinition* inner = phi->getOperand(i)->getOperand(0); |
| 2909 | if (inner->type() != MIRType::Int32) { |
| 2910 | if (!alloc.ensureBallast()) { |
| 2911 | return false; |
| 2912 | } |
| 2913 | MBasicBlock* block = inner->block(); |
| 2914 | inner = MToNumberInt32::New(alloc, inner); |
| 2915 | block->insertBefore(block->lastIns(), inner->toInstruction()); |
| 2916 | } |
| 2917 | MOZ_ASSERT(inner->type() == MIRType::Int32)do { static_assert( mozilla::detail::AssertionConditionType< decltype(inner->type() == MIRType::Int32)>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(inner->type() == MIRType:: Int32))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("inner->type() == MIRType::Int32", "./../../../../js/src/jit/RangeAnalysis.cpp" , 2917); AnnotateMozCrashReason("MOZ_ASSERT" "(" "inner->type() == MIRType::Int32" ")"); do { MOZ_CrashSequence(__null, 2917); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 2918 | phi->replaceOperand(i, inner); |
| 2919 | } |
| 2920 | |
| 2921 | phi->setResultType(MIRType::Int32); |
| 2922 | return true; |
| 2923 | } |
| 2924 | |
| 2925 | // Truncating instruction result is an optimization which implies |
| 2926 | // knowing all uses of an instruction. This implies that if one of |
| 2927 | // the uses got removed, then Range Analysis is not be allowed to do |
| 2928 | // any modification which can change the result, especially if the |
| 2929 | // result can be observed. |
| 2930 | // |
| 2931 | // This corner can easily be understood with UCE examples, but it |
| 2932 | // might also happen with type inference assumptions. Note: Type |
| 2933 | // inference is implicitly branches where other types might be |
| 2934 | // flowing into. |
| 2935 | static bool CloneForDeadBranches(TempAllocator& alloc, |
| 2936 | MInstruction* candidate) { |
| 2937 | // Compare returns a boolean so it doesn't have to be recovered on bailout |
| 2938 | // because the output would remain correct. |
| 2939 | if (candidate->isCompare()) { |
| 2940 | return true; |
| 2941 | } |
| 2942 | |
| 2943 | MOZ_ASSERT(candidate->canClone())do { static_assert( mozilla::detail::AssertionConditionType< decltype(candidate->canClone())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(candidate->canClone()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("candidate->canClone()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 2943); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "candidate->canClone()" ")"); do { MOZ_CrashSequence (__null, 2943); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 2944 | if (!alloc.ensureBallast()) { |
| 2945 | return false; |
| 2946 | } |
| 2947 | |
| 2948 | MDefinitionVector operands(alloc); |
| 2949 | size_t end = candidate->numOperands(); |
| 2950 | if (!operands.reserve(end)) { |
| 2951 | return false; |
| 2952 | } |
| 2953 | for (size_t i = 0; i < end; ++i) { |
| 2954 | operands.infallibleAppend(candidate->getOperand(i)); |
| 2955 | } |
| 2956 | |
| 2957 | MInstruction* clone = candidate->clone(alloc, operands); |
| 2958 | if (!clone) { |
| 2959 | return false; |
| 2960 | } |
| 2961 | clone->setRange(nullptr); |
| 2962 | |
| 2963 | // Set ImplicitlyUsed flag on the cloned instruction in order to chain recover |
| 2964 | // instruction for the bailout path. |
| 2965 | clone->setImplicitlyUsedUnchecked(); |
| 2966 | |
| 2967 | candidate->block()->insertBefore(candidate, clone); |
| 2968 | |
| 2969 | if (!candidate->maybeConstantValue()) { |
| 2970 | MOZ_ASSERT(clone->canRecoverOnBailout())do { static_assert( mozilla::detail::AssertionConditionType< decltype(clone->canRecoverOnBailout())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(clone->canRecoverOnBailout ()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("clone->canRecoverOnBailout()", "./../../../../js/src/jit/RangeAnalysis.cpp" , 2970); AnnotateMozCrashReason("MOZ_ASSERT" "(" "clone->canRecoverOnBailout()" ")"); do { MOZ_CrashSequence(__null, 2970); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 2971 | clone->setRecoveredOnBailout(); |
| 2972 | } |
| 2973 | |
| 2974 | // Replace the candidate by its recovered on bailout clone within recovered |
| 2975 | // instructions and resume points operands. |
| 2976 | for (MUseIterator i(candidate->usesBegin()); i != candidate->usesEnd();) { |
| 2977 | MUse* use = *i++; |
| 2978 | MNode* ins = use->consumer(); |
| 2979 | if (ins->isDefinition() && !ins->toDefinition()->isRecoveredOnBailout()) { |
| 2980 | continue; |
| 2981 | } |
| 2982 | |
| 2983 | use->replaceProducer(clone); |
| 2984 | } |
| 2985 | |
| 2986 | return true; |
| 2987 | } |
| 2988 | |
| 2989 | struct ComputedTruncateKind { |
| 2990 | TruncateKind kind = TruncateKind::NoTruncate; |
| 2991 | bool shouldClone = false; |
| 2992 | }; |
| 2993 | |
| 2994 | // Examine all the users of |candidate| and determine the most aggressive |
| 2995 | // truncate kind that satisfies all of them. |
| 2996 | static ComputedTruncateKind ComputeRequestedTruncateKind( |
| 2997 | const MDefinition* candidate) { |
| 2998 | // Don't call this method when truncation isn't supported, because the result |
| 2999 | // isn't used anyway. |
| 3000 | MOZ_ASSERT(candidate->canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(candidate->canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(candidate->canTruncate()) )), 0))) { do { } while (false); MOZ_ReportAssertionFailure("candidate->canTruncate()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3000); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "candidate->canTruncate()" ")"); do { MOZ_CrashSequence (__null, 3000); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 3001 | |
| 3002 | bool isCapturedResult = |
| 3003 | false; // Check if used by a recovered instruction or a resume point. |
| 3004 | bool isObservableResult = |
| 3005 | false; // Check if it can be read from another frame. |
| 3006 | bool isRecoverableResult = true; // Check if it can safely be reconstructed. |
| 3007 | bool isImplicitlyUsed = candidate->isImplicitlyUsed(); |
| 3008 | bool hasTryBlock = candidate->block()->graph().hasTryBlock(); |
| 3009 | |
| 3010 | TruncateKind kind = TruncateKind::Truncate; |
| 3011 | for (MUseIterator use(candidate->usesBegin()); use != candidate->usesEnd(); |
| 3012 | use++) { |
| 3013 | if (use->consumer()->isResumePoint()) { |
| 3014 | // Truncation is a destructive optimization, as such, we need to pay |
| 3015 | // attention to removed branches and prevent optimization |
| 3016 | // destructive optimizations if we have no alternative. (see |
| 3017 | // ImplicitlyUsed flag) |
| 3018 | isCapturedResult = true; |
| 3019 | isObservableResult = |
| 3020 | isObservableResult || |
| 3021 | use->consumer()->toResumePoint()->isObservableOperand(*use); |
| 3022 | isRecoverableResult = |
| 3023 | isRecoverableResult && |
| 3024 | use->consumer()->toResumePoint()->isRecoverableOperand(*use); |
| 3025 | continue; |
| 3026 | } |
| 3027 | |
| 3028 | MDefinition* consumer = use->consumer()->toDefinition(); |
| 3029 | if (consumer->isRecoveredOnBailout()) { |
| 3030 | isCapturedResult = true; |
| 3031 | isImplicitlyUsed = isImplicitlyUsed || consumer->isImplicitlyUsed(); |
| 3032 | continue; |
| 3033 | } |
| 3034 | |
| 3035 | TruncateKind consumerKind = |
| 3036 | consumer->operandTruncateKind(consumer->indexOf(*use)); |
| 3037 | kind = std::min(kind, consumerKind); |
| 3038 | if (kind == TruncateKind::NoTruncate) { |
| 3039 | break; |
| 3040 | } |
| 3041 | } |
| 3042 | |
| 3043 | // We cannot do full truncation on guarded instructions. |
| 3044 | if (candidate->isGuard() || candidate->isGuardRangeBailouts()) { |
| 3045 | kind = std::min(kind, TruncateKind::TruncateAfterBailouts); |
| 3046 | } |
| 3047 | |
| 3048 | // If the value naturally produces an int32 value (before bailout checks) |
| 3049 | // that needs no conversion, we don't have to worry about resume points |
| 3050 | // seeing truncated values. |
| 3051 | bool needsConversion = !candidate->range() || !candidate->range()->isInt32(); |
| 3052 | |
| 3053 | // If the instruction is explicitly truncated (not indirectly) by all its |
| 3054 | // uses and if it is not implicitly used, then we can safely encode its |
| 3055 | // truncated result as part of the resume point operands. This is safe, |
| 3056 | // because even if we resume with a truncated double, the next baseline |
| 3057 | // instruction operating on this instruction is going to be a no-op. |
| 3058 | // |
| 3059 | // Note, that if the result can be observed from another frame, then this |
| 3060 | // optimization is not safe. Similarly, if this function contains a try |
| 3061 | // block, the result could be observed from a catch block, which we do |
| 3062 | // not compile. |
| 3063 | bool safeToConvert = kind == TruncateKind::Truncate && !isImplicitlyUsed && |
| 3064 | !isObservableResult && !hasTryBlock; |
| 3065 | |
| 3066 | // If the candidate instruction appears as operand of a resume point or a |
| 3067 | // recover instruction, and we have to truncate its result, then we might |
| 3068 | // have to either recover the result during the bailout, or avoid the |
| 3069 | // truncation. |
| 3070 | bool shouldClone = false; |
| 3071 | if (isCapturedResult && needsConversion && !safeToConvert) { |
| 3072 | // If the result can be recovered from all the resume points (not needed |
| 3073 | // for iterating over the inlined frames), and this instruction can be |
| 3074 | // recovered on bailout, then we can clone it and use the cloned |
| 3075 | // instruction to encode the recover instruction. Otherwise, we should |
| 3076 | // keep the original result and bailout if the value is not in the int32 |
| 3077 | // range. |
| 3078 | if (!JitOptions.disableRecoverIns && isRecoverableResult && |
| 3079 | candidate->canRecoverOnBailout()) { |
| 3080 | shouldClone = true; |
| 3081 | } else { |
| 3082 | kind = std::min(kind, TruncateKind::TruncateAfterBailouts); |
| 3083 | } |
| 3084 | } |
| 3085 | |
| 3086 | return {kind, shouldClone}; |
| 3087 | } |
| 3088 | |
| 3089 | static ComputedTruncateKind ComputeTruncateKind(const MDefinition* candidate) { |
| 3090 | // Don't call this method when truncation isn't supported, because the result |
| 3091 | // isn't used anyway. |
| 3092 | MOZ_ASSERT(candidate->canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(candidate->canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(candidate->canTruncate()) )), 0))) { do { } while (false); MOZ_ReportAssertionFailure("candidate->canTruncate()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3092); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "candidate->canTruncate()" ")"); do { MOZ_CrashSequence (__null, 3092); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 3093 | |
| 3094 | // Compare operations might coerce its inputs to int32 if the ranges are |
| 3095 | // correct. So we do not need to check if all uses are coerced. |
| 3096 | if (candidate->isCompare()) { |
| 3097 | return {TruncateKind::TruncateAfterBailouts}; |
| 3098 | } |
| 3099 | |
| 3100 | // Set truncated flag if range analysis ensure that it has no |
| 3101 | // rounding errors and no fractional part. Note that we can't use |
| 3102 | // the MDefinition Range constructor, because we need to know if |
| 3103 | // the value will have rounding errors before any bailout checks. |
| 3104 | const Range* r = candidate->range(); |
| 3105 | bool canHaveRoundingErrors = !r || r->canHaveRoundingErrors(); |
| 3106 | |
| 3107 | // Special case integer division and modulo: a/b can be infinite, and a%b |
| 3108 | // can be NaN but cannot actually have rounding errors induced by truncation. |
| 3109 | if ((candidate->isDiv() || candidate->isMod()) && |
| 3110 | candidate->type() == MIRType::Int32) { |
| 3111 | canHaveRoundingErrors = false; |
| 3112 | } |
| 3113 | |
| 3114 | if (canHaveRoundingErrors) { |
| 3115 | return {TruncateKind::NoTruncate}; |
| 3116 | } |
| 3117 | |
| 3118 | // Ensure all observable uses are truncated. |
| 3119 | return ComputeRequestedTruncateKind(candidate); |
| 3120 | } |
| 3121 | |
| 3122 | static void RemoveTruncatesOnOutput(MDefinition* truncated) { |
| 3123 | // Compare returns a boolean so it doesn't have any output truncates. |
| 3124 | if (truncated->isCompare()) { |
| 3125 | return; |
| 3126 | } |
| 3127 | |
| 3128 | MOZ_ASSERT(truncated->type() == MIRType::Int32)do { static_assert( mozilla::detail::AssertionConditionType< decltype(truncated->type() == MIRType::Int32)>::isValid , "invalid assertion condition"); if ((__builtin_expect(!!(!( !!(truncated->type() == MIRType::Int32))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("truncated->type() == MIRType::Int32" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3128); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "truncated->type() == MIRType::Int32" ")" ); do { MOZ_CrashSequence(__null, 3128); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 3129 | MOZ_ASSERT(Range(truncated).isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(Range(truncated).isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(Range(truncated).isInt32())) ), 0))) { do { } while (false); MOZ_ReportAssertionFailure("Range(truncated).isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3129); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "Range(truncated).isInt32()" ")"); do { MOZ_CrashSequence (__null, 3129); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 3130 | |
| 3131 | for (MUseDefIterator use(truncated); use; use++) { |
| 3132 | MDefinition* def = use.def(); |
| 3133 | if (!def->isTruncateToInt32() && !def->isToNumberInt32()) { |
| 3134 | continue; |
| 3135 | } |
| 3136 | |
| 3137 | def->replaceAllUsesWith(truncated); |
| 3138 | } |
| 3139 | } |
| 3140 | |
| 3141 | void RangeAnalysis::adjustTruncatedInputs(MDefinition* truncated) { |
| 3142 | MBasicBlock* block = truncated->block(); |
| 3143 | for (size_t i = 0, e = truncated->numOperands(); i < e; i++) { |
| 3144 | TruncateKind kind = truncated->operandTruncateKind(i); |
| 3145 | if (kind == TruncateKind::NoTruncate) { |
| 3146 | continue; |
| 3147 | } |
| 3148 | |
| 3149 | MDefinition* input = truncated->getOperand(i); |
| 3150 | if (input->type() == MIRType::Int32) { |
| 3151 | continue; |
| 3152 | } |
| 3153 | |
| 3154 | if (input->isToDouble() && input->getOperand(0)->type() == MIRType::Int32) { |
| 3155 | truncated->replaceOperand(i, input->getOperand(0)); |
| 3156 | } else { |
| 3157 | MInstruction* op; |
| 3158 | if (kind == TruncateKind::TruncateAfterBailouts) { |
| 3159 | MOZ_ASSERT(!mir->outerInfo().hadEagerTruncationBailout())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!mir->outerInfo().hadEagerTruncationBailout())> ::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(!mir->outerInfo().hadEagerTruncationBailout()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("!mir->outerInfo().hadEagerTruncationBailout()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3159); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "!mir->outerInfo().hadEagerTruncationBailout()" ")"); do { MOZ_CrashSequence(__null, 3159); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 3160 | op = MToNumberInt32::New(alloc(), truncated->getOperand(i)); |
| 3161 | op->setBailoutKind(BailoutKind::EagerTruncation); |
| 3162 | } else { |
| 3163 | op = MTruncateToInt32::New(alloc(), truncated->getOperand(i)); |
| 3164 | } |
| 3165 | |
| 3166 | if (truncated->isPhi()) { |
| 3167 | MBasicBlock* pred = block->getPredecessor(i); |
| 3168 | pred->insertBefore(pred->lastIns(), op); |
| 3169 | } else { |
| 3170 | block->insertBefore(truncated->toInstruction(), op); |
| 3171 | } |
| 3172 | truncated->replaceOperand(i, op); |
| 3173 | } |
| 3174 | } |
| 3175 | |
| 3176 | if (truncated->isToDouble()) { |
| 3177 | truncated->replaceAllUsesWith(truncated->toToDouble()->getOperand(0)); |
| 3178 | block->discard(truncated->toToDouble()); |
| 3179 | } |
| 3180 | } |
| 3181 | |
| 3182 | bool RangeAnalysis::canTruncate(const MDefinition* def, |
| 3183 | TruncateKind kind) const { |
| 3184 | // Don't call this method when truncation isn't supported, because the result |
| 3185 | // isn't used anyway. |
| 3186 | MOZ_ASSERT(def->canTruncate())do { static_assert( mozilla::detail::AssertionConditionType< decltype(def->canTruncate())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(def->canTruncate()))), 0) )) { do { } while (false); MOZ_ReportAssertionFailure("def->canTruncate()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3186); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "def->canTruncate()" ")"); do { MOZ_CrashSequence (__null, 3186); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 3187 | |
| 3188 | if (kind == TruncateKind::NoTruncate) { |
| 3189 | return false; |
| 3190 | } |
| 3191 | |
| 3192 | // Range Analysis is sometimes eager to do optimizations, even if we |
| 3193 | // are not able to truncate an instruction. In such case, we |
| 3194 | // speculatively compile the instruction to an int32 instruction |
| 3195 | // while adding a guard. This is what is implied by |
| 3196 | // TruncateAfterBailout. |
| 3197 | // |
| 3198 | // If a previous compilation was invalidated because a speculative |
| 3199 | // truncation bailed out, we no longer attempt to make this kind of |
| 3200 | // eager optimization. |
| 3201 | if (mir->outerInfo().hadEagerTruncationBailout()) { |
| 3202 | if (kind == TruncateKind::TruncateAfterBailouts) { |
| 3203 | return false; |
| 3204 | } |
| 3205 | // MDiv and MMod always require TruncateAfterBailout for their operands. |
| 3206 | // See MDiv::operandTruncateKind and MMod::operandTruncateKind. |
| 3207 | if (def->isDiv() || def->isMod()) { |
| 3208 | return false; |
| 3209 | } |
| 3210 | } |
| 3211 | |
| 3212 | return true; |
| 3213 | } |
| 3214 | |
| 3215 | // Iterate backward on all instruction and attempt to truncate operations for |
| 3216 | // each instruction which respect the following list of predicates: Has been |
| 3217 | // analyzed by range analysis, the range has no rounding errors, all uses cases |
| 3218 | // are truncating the result. |
| 3219 | // |
| 3220 | // If the truncation of the operation is successful, then the instruction is |
| 3221 | // queue for later updating the graph to restore the type correctness by |
| 3222 | // converting the operands that need to be truncated. |
| 3223 | // |
| 3224 | // We iterate backward because it is likely that a truncated operation truncates |
| 3225 | // some of its operands. |
| 3226 | bool RangeAnalysis::truncate() { |
| 3227 | JitSpew(JitSpew_Range, "Do range-base truncation (backward loop)"); |
| 3228 | |
| 3229 | // Automatic truncation is disabled for wasm because the truncation logic |
| 3230 | // is based on IonMonkey which assumes that we can bailout if the truncation |
| 3231 | // logic fails. As wasm code has no bailout mechanism, it is safer to avoid |
| 3232 | // any automatic truncations. |
| 3233 | MOZ_ASSERT(!mir->compilingWasm())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!mir->compilingWasm())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(!mir->compilingWasm()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("!mir->compilingWasm()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3233); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "!mir->compilingWasm()" ")"); do { MOZ_CrashSequence (__null, 3233); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 3234 | |
| 3235 | Vector<MDefinition*, 16, SystemAllocPolicy> worklist; |
| 3236 | |
| 3237 | for (PostorderIterator block(graph_.poBegin()); block != graph_.poEnd(); |
| 3238 | block++) { |
| 3239 | if (mir->shouldCancel("RangeAnalysis truncate")) { |
| 3240 | return false; |
| 3241 | } |
| 3242 | |
| 3243 | for (MInstructionReverseIterator iter(block->rbegin()); |
| 3244 | iter != block->rend(); iter++) { |
| 3245 | if (iter->isRecoveredOnBailout()) { |
| 3246 | continue; |
| 3247 | } |
| 3248 | |
| 3249 | if (iter->type() == MIRType::None) { |
| 3250 | if (iter->isTest()) { |
| 3251 | if (!TruncateTest(alloc(), iter->toTest())) { |
| 3252 | return false; |
| 3253 | } |
| 3254 | } |
| 3255 | continue; |
| 3256 | } |
| 3257 | |
| 3258 | // Remember all bitop instructions for folding after range analysis. |
| 3259 | switch (iter->op()) { |
| 3260 | case MDefinition::Opcode::BitAnd: |
| 3261 | case MDefinition::Opcode::BitOr: |
| 3262 | case MDefinition::Opcode::BitXor: |
| 3263 | case MDefinition::Opcode::Lsh: |
| 3264 | case MDefinition::Opcode::Rsh: |
| 3265 | case MDefinition::Opcode::Ursh: |
| 3266 | if (!bitops.append(static_cast<MBinaryBitwiseInstruction*>(*iter))) { |
| 3267 | return false; |
| 3268 | } |
| 3269 | break; |
| 3270 | default:; |
| 3271 | } |
| 3272 | |
| 3273 | // Skip instructions which can't be truncated. |
| 3274 | if (!iter->canTruncate()) { |
| 3275 | continue; |
| 3276 | } |
| 3277 | |
| 3278 | auto [kind, shouldClone] = ComputeTruncateKind(*iter); |
| 3279 | |
| 3280 | // Truncate this instruction if possible. |
| 3281 | if (!canTruncate(*iter, kind)) { |
| 3282 | continue; |
| 3283 | } |
| 3284 | |
| 3285 | SpewTruncate(*iter, kind, shouldClone); |
| 3286 | |
| 3287 | // If needed, clone the current instruction for keeping it for the |
| 3288 | // bailout path. This give us the ability to truncate instructions |
| 3289 | // even after the removal of branches. |
| 3290 | if (shouldClone && !CloneForDeadBranches(alloc(), *iter)) { |
| 3291 | return false; |
| 3292 | } |
| 3293 | |
| 3294 | // TruncateAfterBailouts keeps the bailout code as-is and |
| 3295 | // continues with truncated operations, with the expectation |
| 3296 | // that we are unlikely to bail out. If we do bail out, then we |
| 3297 | // will set a flag in FinishBailoutToBaseline to prevent eager |
| 3298 | // truncation when we recompile, to avoid bailout loops. |
| 3299 | if (kind == TruncateKind::TruncateAfterBailouts) { |
| 3300 | iter->setBailoutKind(BailoutKind::EagerTruncation); |
| 3301 | } |
| 3302 | |
| 3303 | iter->truncate(kind); |
| 3304 | |
| 3305 | // Delay updates of inputs/outputs to avoid creating node which |
| 3306 | // would be removed by the truncation of the next operations. |
| 3307 | iter->setInWorklist(); |
| 3308 | if (!worklist.append(*iter)) { |
| 3309 | return false; |
| 3310 | } |
| 3311 | } |
| 3312 | for (MPhiIterator iter(block->phisBegin()), end(block->phisEnd()); |
| 3313 | iter != end; ++iter) { |
| 3314 | // Skip phis which can't be truncated. |
| 3315 | if (!iter->canTruncate()) { |
| 3316 | continue; |
| 3317 | } |
| 3318 | |
| 3319 | auto [kind, shouldClone] = ComputeTruncateKind(*iter); |
| 3320 | |
| 3321 | // Truncate this phi if possible. |
| 3322 | if (shouldClone || !canTruncate(*iter, kind)) { |
| 3323 | continue; |
| 3324 | } |
| 3325 | |
| 3326 | SpewTruncate(*iter, kind, shouldClone); |
| 3327 | |
| 3328 | iter->truncate(kind); |
| 3329 | |
| 3330 | // Delay updates of inputs/outputs to avoid creating node which |
| 3331 | // would be removed by the truncation of the next operations. |
| 3332 | iter->setInWorklist(); |
| 3333 | if (!worklist.append(*iter)) { |
| 3334 | return false; |
| 3335 | } |
| 3336 | } |
| 3337 | } |
| 3338 | |
| 3339 | // Update inputs/outputs of truncated instructions. |
| 3340 | JitSpew(JitSpew_Range, "Do graph type fixup (dequeue)"); |
| 3341 | while (!worklist.empty()) { |
| 3342 | if (!alloc().ensureBallast()) { |
| 3343 | return false; |
| 3344 | } |
| 3345 | MDefinition* def = worklist.popCopy(); |
| 3346 | def->setNotInWorklist(); |
| 3347 | RemoveTruncatesOnOutput(def); |
| 3348 | adjustTruncatedInputs(def); |
| 3349 | } |
| 3350 | |
| 3351 | return true; |
| 3352 | } |
| 3353 | |
| 3354 | bool RangeAnalysis::removeUnnecessaryBitops() { |
| 3355 | JitSpew(JitSpew_Range, "Begin (removeUnnecessaryBitops)"); |
| 3356 | // Note: This operation change the semantic of the program in a way which |
| 3357 | // uniquely works with Int32, Recover Instructions added by the Sink phase |
| 3358 | // expects the MIR Graph to still have a valid flow as-if they were double |
| 3359 | // operations instead of Int32 operations. Thus, this phase should be |
| 3360 | // executed after the Sink phase, and before DCE. |
| 3361 | |
| 3362 | // Fold any unnecessary bitops in the graph, such as (x | 0) on an integer |
| 3363 | // input. This is done after range analysis rather than during GVN as the |
| 3364 | // presence of the bitop can change which instructions are truncated. |
| 3365 | for (size_t i = 0; i < bitops.length(); i++) { |
| 3366 | MBinaryBitwiseInstruction* ins = bitops[i]; |
| 3367 | if (ins->isRecoveredOnBailout()) { |
| 3368 | continue; |
| 3369 | } |
| 3370 | |
| 3371 | MDefinition* folded = ins->foldUnnecessaryBitop(); |
| 3372 | if (folded != ins) { |
| 3373 | ins->replaceAllLiveUsesWith(folded); |
| 3374 | ins->setRecoveredOnBailout(); |
| 3375 | } |
| 3376 | } |
| 3377 | |
| 3378 | bitops.clear(); |
| 3379 | return true; |
| 3380 | } |
| 3381 | |
| 3382 | /////////////////////////////////////////////////////////////////////////////// |
| 3383 | // Collect Range information of operands |
| 3384 | /////////////////////////////////////////////////////////////////////////////// |
| 3385 | |
| 3386 | void MInArray::collectRangeInfoPreTrunc() { |
| 3387 | Range indexRange(index()); |
| 3388 | if (indexRange.isFiniteNonNegative()) { |
| 3389 | needsNegativeIntCheck_ = false; |
| 3390 | setNotGuard(); |
| 3391 | } |
| 3392 | } |
| 3393 | |
| 3394 | void MLoadElementHole::collectRangeInfoPreTrunc() { |
| 3395 | Range indexRange(index()); |
| 3396 | if (indexRange.isFiniteNonNegative()) { |
| 3397 | needsNegativeIntCheck_ = false; |
| 3398 | setNotGuard(); |
| 3399 | } |
| 3400 | } |
| 3401 | |
| 3402 | void MInt32ToIntPtr::collectRangeInfoPreTrunc() { |
| 3403 | Range inputRange(input()); |
| 3404 | if (inputRange.isFiniteNonNegative()) { |
| 3405 | canBeNegative_ = false; |
| 3406 | } |
| 3407 | } |
| 3408 | |
| 3409 | void MClz::collectRangeInfoPreTrunc() { |
| 3410 | Range inputRange(input()); |
| 3411 | if (!inputRange.canBeZero()) { |
| 3412 | operandIsNeverZero_ = true; |
| 3413 | } |
| 3414 | } |
| 3415 | |
| 3416 | void MCtz::collectRangeInfoPreTrunc() { |
| 3417 | Range inputRange(input()); |
| 3418 | if (!inputRange.canBeZero()) { |
| 3419 | operandIsNeverZero_ = true; |
| 3420 | } |
| 3421 | } |
| 3422 | |
| 3423 | void MDiv::collectRangeInfoPreTrunc() { |
| 3424 | Range lhsRange(lhs()); |
| 3425 | Range rhsRange(rhs()); |
| 3426 | |
| 3427 | // Test if Dividend is non-negative. |
| 3428 | if (lhsRange.isFiniteNonNegative()) { |
| 3429 | canBeNegativeDividend_ = false; |
| 3430 | } |
| 3431 | |
| 3432 | // Try removing divide by zero check. |
| 3433 | if (!rhsRange.canBeZero()) { |
| 3434 | canBeDivideByZero_ = false; |
| 3435 | } |
| 3436 | |
| 3437 | // If lhsRange does not contain INT32_MIN in its range, |
| 3438 | // negative overflow check can be skipped. |
| 3439 | if (!lhsRange.contains(INT32_MIN(-2147483647-1))) { |
| 3440 | canBeNegativeOverflow_ = false; |
| 3441 | } |
| 3442 | |
| 3443 | // If rhsRange does not contain -1 likewise. |
| 3444 | if (!rhsRange.contains(-1)) { |
| 3445 | canBeNegativeOverflow_ = false; |
| 3446 | } |
| 3447 | |
| 3448 | // If lhsRange does not contain a zero, |
| 3449 | // negative zero check can be skipped. |
| 3450 | if (!lhsRange.canBeZero()) { |
| 3451 | canBeNegativeZero_ = false; |
| 3452 | } |
| 3453 | |
| 3454 | // If rhsRange >= 0 negative zero check can be skipped. |
| 3455 | if (rhsRange.isFiniteNonNegative()) { |
| 3456 | canBeNegativeZero_ = false; |
| 3457 | } |
| 3458 | |
| 3459 | if (type() == MIRType::Int32 && fallible()) { |
| 3460 | setGuardRangeBailoutsUnchecked(); |
| 3461 | } |
| 3462 | } |
| 3463 | |
| 3464 | void MMul::collectRangeInfoPreTrunc() { |
| 3465 | Range lhsRange(lhs()); |
| 3466 | Range rhsRange(rhs()); |
| 3467 | |
| 3468 | // If lhsRange contains only positive then we can skip negative zero check. |
| 3469 | if (lhsRange.isFiniteNonNegative() && !lhsRange.canBeZero()) { |
| 3470 | setCanBeNegativeZero(false); |
| 3471 | } |
| 3472 | |
| 3473 | // Likewise rhsRange. |
| 3474 | if (rhsRange.isFiniteNonNegative() && !rhsRange.canBeZero()) { |
| 3475 | setCanBeNegativeZero(false); |
| 3476 | } |
| 3477 | |
| 3478 | // If rhsRange and lhsRange contain Non-negative integers only, |
| 3479 | // We skip negative zero check. |
| 3480 | if (rhsRange.isFiniteNonNegative() && lhsRange.isFiniteNonNegative()) { |
| 3481 | setCanBeNegativeZero(false); |
| 3482 | } |
| 3483 | |
| 3484 | // If rhsRange and lhsRange < 0. Then we skip negative zero check. |
| 3485 | if (rhsRange.isFiniteNegative() && lhsRange.isFiniteNegative()) { |
| 3486 | setCanBeNegativeZero(false); |
| 3487 | } |
| 3488 | } |
| 3489 | |
| 3490 | void MMod::collectRangeInfoPreTrunc() { |
| 3491 | Range lhsRange(lhs()); |
| 3492 | Range rhsRange(rhs()); |
| 3493 | if (lhsRange.isFiniteNonNegative()) { |
| 3494 | canBeNegativeDividend_ = false; |
| 3495 | } |
| 3496 | if (!rhsRange.canBeZero()) { |
| 3497 | canBeDivideByZero_ = false; |
| 3498 | } |
| 3499 | if (type() == MIRType::Int32 && fallible()) { |
| 3500 | setGuardRangeBailoutsUnchecked(); |
| 3501 | } |
| 3502 | } |
| 3503 | |
| 3504 | void MToNumberInt32::collectRangeInfoPreTrunc() { |
| 3505 | Range inputRange(input()); |
| 3506 | if (!inputRange.canBeNegativeZero()) { |
| 3507 | needsNegativeZeroCheck_ = false; |
| 3508 | } |
| 3509 | } |
| 3510 | |
| 3511 | void MBoundsCheck::collectRangeInfoPreTrunc() { |
| 3512 | Range indexRange(index()); |
| 3513 | Range lengthRange(length()); |
| 3514 | if (!indexRange.hasInt32LowerBound() || !indexRange.hasInt32UpperBound()) { |
| 3515 | return; |
| 3516 | } |
| 3517 | if (!lengthRange.hasInt32LowerBound() || lengthRange.canBeNaN()) { |
| 3518 | return; |
| 3519 | } |
| 3520 | |
| 3521 | int64_t indexLower = indexRange.lower(); |
| 3522 | int64_t indexUpper = indexRange.upper(); |
| 3523 | int64_t lengthLower = lengthRange.lower(); |
| 3524 | int64_t min = minimum(); |
| 3525 | int64_t max = maximum(); |
| 3526 | |
| 3527 | if (indexLower + min >= 0 && indexUpper + max < lengthLower) { |
| 3528 | fallible_ = false; |
| 3529 | } |
| 3530 | } |
| 3531 | |
| 3532 | void MBoundsCheckLower::collectRangeInfoPreTrunc() { |
| 3533 | Range indexRange(index()); |
| 3534 | if (indexRange.hasInt32LowerBound() && indexRange.lower() >= minimum_) { |
| 3535 | fallible_ = false; |
| 3536 | } |
| 3537 | } |
| 3538 | |
| 3539 | void MCompare::collectRangeInfoPreTrunc() { |
| 3540 | if (!Range(lhs()).canBeNaN() && !Range(rhs()).canBeNaN()) { |
| 3541 | operandsAreNeverNaN_ = true; |
| 3542 | } |
| 3543 | } |
| 3544 | |
| 3545 | void MNot::collectRangeInfoPreTrunc() { |
| 3546 | if (!Range(input()).canBeNaN()) { |
| 3547 | operandIsNeverNaN_ = true; |
| 3548 | } |
| 3549 | } |
| 3550 | |
| 3551 | void MPowHalf::collectRangeInfoPreTrunc() { |
| 3552 | Range inputRange(input()); |
| 3553 | if (!inputRange.canBeInfiniteOrNaN() || inputRange.hasInt32LowerBound()) { |
| 3554 | operandIsNeverNegativeInfinity_ = true; |
| 3555 | } |
| 3556 | if (!inputRange.canBeNegativeZero()) { |
| 3557 | operandIsNeverNegativeZero_ = true; |
| 3558 | } |
| 3559 | if (!inputRange.canBeNaN()) { |
| 3560 | operandIsNeverNaN_ = true; |
| 3561 | } |
| 3562 | } |
| 3563 | |
| 3564 | void MUrsh::collectRangeInfoPreTrunc() { |
| 3565 | if (type() == MIRType::Int64) { |
| 3566 | return; |
| 3567 | } |
| 3568 | |
| 3569 | Range lhsRange(lhs()), rhsRange(rhs()); |
| 3570 | |
| 3571 | // As in MUrsh::computeRange(), convert the inputs. |
| 3572 | lhsRange.wrapAroundToInt32(); |
| 3573 | rhsRange.wrapAroundToShiftCount(); |
| 3574 | |
| 3575 | // If the most significant bit of our result is always going to be zero, |
| 3576 | // we can optimize by disabling bailout checks for enforcing an int32 range. |
| 3577 | if (lhsRange.lower() >= 0 || rhsRange.lower() >= 1) { |
| 3578 | bailoutsDisabled_ = true; |
| 3579 | } |
| 3580 | } |
| 3581 | |
| 3582 | static bool DoesMaskMatchRange(int32_t mask, const Range& range) { |
| 3583 | // Check if range is positive, because the bitand operator in `(-3) & 0xff` |
| 3584 | // can't be eliminated. |
| 3585 | if (range.lower() >= 0) { |
| 3586 | MOZ_ASSERT(range.isInt32())do { static_assert( mozilla::detail::AssertionConditionType< decltype(range.isInt32())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(range.isInt32()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("range.isInt32()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3586); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "range.isInt32()" ")"); do { MOZ_CrashSequence (__null, 3586); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 3587 | // Check that the mask value has all bits set given the range upper bound. |
| 3588 | // Note that the upper bound does not have to be exactly the mask value. For |
| 3589 | // example, consider `x & 0xfff` where `x` is a uint8. That expression can |
| 3590 | // still be optimized to `x`. |
| 3591 | int bits = 1 + FloorLog2(uint32_t(range.upper())); |
| 3592 | uint32_t maskNeeded = (bits == 32) ? 0xffffffff : (uint32_t(1) << bits) - 1; |
| 3593 | if ((mask & maskNeeded) == maskNeeded) { |
| 3594 | return true; |
| 3595 | } |
| 3596 | } |
| 3597 | |
| 3598 | return false; |
| 3599 | } |
| 3600 | |
| 3601 | void MBinaryBitwiseInstruction::collectRangeInfoPreTrunc() { |
| 3602 | Range lhsRange(lhs()); |
| 3603 | Range rhsRange(rhs()); |
| 3604 | |
| 3605 | if (lhs()->isConstant() && lhs()->type() == MIRType::Int32 && |
| 3606 | DoesMaskMatchRange(lhs()->toConstant()->toInt32(), rhsRange)) { |
| 3607 | maskMatchesRightRange = true; |
| 3608 | } |
| 3609 | |
| 3610 | if (rhs()->isConstant() && rhs()->type() == MIRType::Int32 && |
| 3611 | DoesMaskMatchRange(rhs()->toConstant()->toInt32(), lhsRange)) { |
| 3612 | maskMatchesLeftRange = true; |
| 3613 | } |
| 3614 | } |
| 3615 | |
| 3616 | void MNaNToZero::collectRangeInfoPreTrunc() { |
| 3617 | Range inputRange(input()); |
| 3618 | |
| 3619 | if (!inputRange.canBeNaN()) { |
| 3620 | operandIsNeverNaN_ = true; |
| 3621 | } |
| 3622 | if (!inputRange.canBeNegativeZero()) { |
| 3623 | operandIsNeverNegativeZero_ = true; |
| 3624 | } |
| 3625 | } |
| 3626 | |
| 3627 | bool RangeAnalysis::prepareForUCE(bool* shouldRemoveDeadCode) { |
| 3628 | *shouldRemoveDeadCode = false; |
| 3629 | |
| 3630 | for (ReversePostorderIterator iter(graph_.rpoBegin()); |
| 3631 | iter != graph_.rpoEnd(); iter++) { |
| 3632 | MBasicBlock* block = *iter; |
| 3633 | |
| 3634 | if (!block->unreachable()) { |
| 3635 | continue; |
| 3636 | } |
| 3637 | |
| 3638 | // Filter out unreachable fake entries. |
| 3639 | if (block->numPredecessors() == 0) { |
| 3640 | // Ignore fixup blocks added by the Value Numbering phase, in order |
| 3641 | // to keep the dominator tree as-is when we have OSR Block which are |
| 3642 | // no longer reachable from the main entry point of the graph. |
| 3643 | MOZ_ASSERT(graph_.osrBlock())do { static_assert( mozilla::detail::AssertionConditionType< decltype(graph_.osrBlock())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(graph_.osrBlock()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure("graph_.osrBlock()" , "./../../../../js/src/jit/RangeAnalysis.cpp", 3643); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "graph_.osrBlock()" ")"); do { MOZ_CrashSequence (__null, 3643); __attribute__((nomerge)) ::abort(); } while ( false); } } while (false); |
| 3644 | continue; |
| 3645 | } |
| 3646 | |
| 3647 | MControlInstruction* cond = block->getPredecessor(0)->lastIns(); |
| 3648 | if (!cond->isTest()) { |
| 3649 | continue; |
| 3650 | } |
| 3651 | |
| 3652 | // Replace the condition of the test control instruction by a constant |
| 3653 | // chosen based which of the successors has the unreachable flag which is |
| 3654 | // added by MBeta::computeRange on its own block. |
| 3655 | MTest* test = cond->toTest(); |
| 3656 | MDefinition* condition = test->input(); |
| 3657 | |
| 3658 | // If the false-branch is unreachable, then the test condition must be true. |
| 3659 | // If the true-branch is unreachable, then the test condition must be false. |
| 3660 | MOZ_ASSERT(block == test->ifTrue() || block == test->ifFalse())do { static_assert( mozilla::detail::AssertionConditionType< decltype(block == test->ifTrue() || block == test->ifFalse ())>::isValid, "invalid assertion condition"); if ((__builtin_expect (!!(!(!!(block == test->ifTrue() || block == test->ifFalse ()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("block == test->ifTrue() || block == test->ifFalse()", "./../../../../js/src/jit/RangeAnalysis.cpp", 3660); AnnotateMozCrashReason ("MOZ_ASSERT" "(" "block == test->ifTrue() || block == test->ifFalse()" ")"); do { MOZ_CrashSequence(__null, 3660); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 3661 | bool value = block == test->ifFalse(); |
| 3662 | MConstant* constant = |
| 3663 | MConstant::New(alloc().fallible(), BooleanValue(value)); |
| 3664 | if (!constant) { |
| 3665 | return false; |
| 3666 | } |
| 3667 | |
| 3668 | condition->setGuardRangeBailoutsUnchecked(); |
| 3669 | |
| 3670 | test->block()->insertBefore(test, constant); |
| 3671 | |
| 3672 | test->replaceOperand(0, constant); |
| 3673 | JitSpew(JitSpew_Range, |
| 3674 | "Update condition of %u to reflect unreachable branches.", |
| 3675 | test->id()); |
| 3676 | |
| 3677 | *shouldRemoveDeadCode = true; |
| 3678 | } |
| 3679 | |
| 3680 | return tryRemovingGuards(); |
| 3681 | } |
| 3682 | |
| 3683 | bool RangeAnalysis::tryRemovingGuards() { |
| 3684 | MDefinitionVector guards(alloc()); |
| 3685 | |
| 3686 | for (ReversePostorderIterator block = graph_.rpoBegin(); |
| 3687 | block != graph_.rpoEnd(); block++) { |
| 3688 | if (mir->shouldCancel("RangeAnalysis tryRemovingGuards (block loop)")) { |
| 3689 | return false; |
| 3690 | } |
| 3691 | |
| 3692 | for (MDefinitionIterator iter(*block); iter; iter++) { |
| 3693 | if (!iter->isGuardRangeBailouts()) { |
| 3694 | continue; |
| 3695 | } |
| 3696 | |
| 3697 | iter->setInWorklist(); |
| 3698 | if (!guards.append(*iter)) { |
| 3699 | return false; |
| 3700 | } |
| 3701 | } |
| 3702 | } |
| 3703 | |
| 3704 | // Flag all fallible instructions which were indirectly used in the |
| 3705 | // computation of the condition, such that we do not ignore |
| 3706 | // bailout-paths which are used to shrink the input range of the |
| 3707 | // operands of the condition. |
| 3708 | for (size_t i = 0; i < guards.length(); i++) { |
| 3709 | if (mir->shouldCancel("RangeAnalysis tryRemovingGuards (guards loop)")) { |
| 3710 | return false; |
| 3711 | } |
| 3712 | |
| 3713 | MDefinition* guard = guards[i]; |
| 3714 | |
| 3715 | // If this ins is a guard even without guardRangeBailouts, |
| 3716 | // there is no reason in trying to hoist the guardRangeBailouts check. |
| 3717 | guard->setNotGuardRangeBailouts(); |
| 3718 | if (!DeadIfUnused(guard)) { |
| 3719 | guard->setGuardRangeBailouts(); |
| 3720 | continue; |
| 3721 | } |
| 3722 | guard->setGuardRangeBailouts(); |
| 3723 | |
| 3724 | if (!guard->isPhi()) { |
| 3725 | if (!guard->range()) { |
| 3726 | continue; |
| 3727 | } |
| 3728 | |
| 3729 | // Filter the range of the instruction based on its MIRType. |
| 3730 | Range typeFilteredRange(guard); |
| 3731 | |
| 3732 | // If the output range is updated by adding the inner range, |
| 3733 | // then the MIRType act as an effectful filter. As we do not know if |
| 3734 | // this filtered Range might change or not the result of the |
| 3735 | // previous comparison, we have to keep this instruction as a guard |
| 3736 | // because it has to bailout in order to restrict the Range to its |
| 3737 | // MIRType. |
| 3738 | if (typeFilteredRange.update(guard->range())) { |
| 3739 | continue; |
| 3740 | } |
| 3741 | } |
| 3742 | |
| 3743 | guard->setNotGuardRangeBailouts(); |
| 3744 | |
| 3745 | // Propagate the guard to its operands. |
| 3746 | for (size_t op = 0, e = guard->numOperands(); op < e; op++) { |
| 3747 | MDefinition* operand = guard->getOperand(op); |
| 3748 | |
| 3749 | // Already marked. |
| 3750 | if (operand->isInWorklist()) { |
| 3751 | continue; |
| 3752 | } |
| 3753 | |
| 3754 | MOZ_ASSERT(!operand->isGuardRangeBailouts())do { static_assert( mozilla::detail::AssertionConditionType< decltype(!operand->isGuardRangeBailouts())>::isValid, "invalid assertion condition" ); if ((__builtin_expect(!!(!(!!(!operand->isGuardRangeBailouts ()))), 0))) { do { } while (false); MOZ_ReportAssertionFailure ("!operand->isGuardRangeBailouts()", "./../../../../js/src/jit/RangeAnalysis.cpp" , 3754); AnnotateMozCrashReason("MOZ_ASSERT" "(" "!operand->isGuardRangeBailouts()" ")"); do { MOZ_CrashSequence(__null, 3754); __attribute__((nomerge )) ::abort(); } while (false); } } while (false); |
| 3755 | |
| 3756 | operand->setInWorklist(); |
| 3757 | operand->setGuardRangeBailouts(); |
| 3758 | if (!guards.append(operand)) { |
| 3759 | return false; |
| 3760 | } |
| 3761 | } |
| 3762 | } |
| 3763 | |
| 3764 | for (size_t i = 0; i < guards.length(); i++) { |
| 3765 | MDefinition* guard = guards[i]; |
| 3766 | guard->setNotInWorklist(); |
| 3767 | } |
| 3768 | |
| 3769 | return true; |
| 3770 | } |