1 // Copyright 2014 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "src/compiler/machine-operator-reducer.h"
6 #include <cmath>
7 #include <limits>
8
9 #include "src/base/bits.h"
10 #include "src/base/division-by-constant.h"
11 #include "src/base/ieee754.h"
12 #include "src/base/overflowing-math.h"
13 #include "src/compiler/diamond.h"
14 #include "src/compiler/graph.h"
15 #include "src/compiler/machine-graph.h"
16 #include "src/compiler/node-matchers.h"
17 #include "src/compiler/node-properties.h"
18 #include "src/compiler/opcodes.h"
19 #include "src/numbers/conversions-inl.h"
20
21 namespace v8 {
22 namespace internal {
23 namespace compiler {
24
25 // Some optimizations performed by the MachineOperatorReducer can be applied
26 // to both Word32 and Word64 operations. Those are implemented in a generic
27 // way to be reused for different word sizes.
28 // This class adapts a generic algorithm to Word32 operations.
29 class Word32Adapter {
30 public:
31 using IntNBinopMatcher = Int32BinopMatcher;
32 using UintNBinopMatcher = Uint32BinopMatcher;
33 using intN_t = int32_t;
34 // WORD_SIZE refers to the N for which this adapter specializes.
35 static constexpr std::size_t WORD_SIZE = 32;
36
Word32Adapter(MachineOperatorReducer * reducer)37 explicit Word32Adapter(MachineOperatorReducer* reducer) : r_(reducer) {}
38
39 template <typename T>
IsWordNAnd(const T & x)40 static bool IsWordNAnd(const T& x) {
41 return x.IsWord32And();
42 }
43 template <typename T>
IsWordNShl(const T & x)44 static bool IsWordNShl(const T& x) {
45 return x.IsWord32Shl();
46 }
47 template <typename T>
IsWordNShr(const T & x)48 static bool IsWordNShr(const T& x) {
49 return x.IsWord32Shr();
50 }
51 template <typename T>
IsWordNSar(const T & x)52 static bool IsWordNSar(const T& x) {
53 return x.IsWord32Sar();
54 }
55 template <typename T>
IsWordNXor(const T & x)56 static bool IsWordNXor(const T& x) {
57 return x.IsWord32Xor();
58 }
59 template <typename T>
IsIntNAdd(const T & x)60 static bool IsIntNAdd(const T& x) {
61 return x.IsInt32Add();
62 }
63 template <typename T>
IsIntNMul(const T & x)64 static bool IsIntNMul(const T& x) {
65 return x.IsInt32Mul();
66 }
67
IntNAdd(MachineOperatorBuilder * machine)68 const Operator* IntNAdd(MachineOperatorBuilder* machine) {
69 return machine->Int32Add();
70 }
71
ReplaceIntN(int32_t value)72 Reduction ReplaceIntN(int32_t value) { return r_->ReplaceInt32(value); }
ReduceWordNAnd(Node * node)73 Reduction ReduceWordNAnd(Node* node) { return r_->ReduceWord32And(node); }
ReduceIntNAdd(Node * node)74 Reduction ReduceIntNAdd(Node* node) { return r_->ReduceInt32Add(node); }
TryMatchWordNRor(Node * node)75 Reduction TryMatchWordNRor(Node* node) { return r_->TryMatchWord32Ror(node); }
76
IntNConstant(int32_t value)77 Node* IntNConstant(int32_t value) { return r_->Int32Constant(value); }
UintNConstant(uint32_t value)78 Node* UintNConstant(uint32_t value) { return r_->Uint32Constant(value); }
WordNAnd(Node * lhs,Node * rhs)79 Node* WordNAnd(Node* lhs, Node* rhs) { return r_->Word32And(lhs, rhs); }
80
81 private:
82 MachineOperatorReducer* r_;
83 };
84
85 // Some optimizations performed by the MachineOperatorReducer can be applied
86 // to both Word32 and Word64 operations. Those are implemented in a generic
87 // way to be reused for different word sizes.
88 // This class adapts a generic algorithm to Word64 operations.
89 class Word64Adapter {
90 public:
91 using IntNBinopMatcher = Int64BinopMatcher;
92 using UintNBinopMatcher = Uint64BinopMatcher;
93 using intN_t = int64_t;
94 // WORD_SIZE refers to the N for which this adapter specializes.
95 static constexpr std::size_t WORD_SIZE = 64;
96
Word64Adapter(MachineOperatorReducer * reducer)97 explicit Word64Adapter(MachineOperatorReducer* reducer) : r_(reducer) {}
98
99 template <typename T>
IsWordNAnd(const T & x)100 static bool IsWordNAnd(const T& x) {
101 return x.IsWord64And();
102 }
103 template <typename T>
IsWordNShl(const T & x)104 static bool IsWordNShl(const T& x) {
105 return x.IsWord64Shl();
106 }
107 template <typename T>
IsWordNShr(const T & x)108 static bool IsWordNShr(const T& x) {
109 return x.IsWord64Shr();
110 }
111 template <typename T>
IsWordNSar(const T & x)112 static bool IsWordNSar(const T& x) {
113 return x.IsWord64Sar();
114 }
115 template <typename T>
IsWordNXor(const T & x)116 static bool IsWordNXor(const T& x) {
117 return x.IsWord64Xor();
118 }
119 template <typename T>
IsIntNAdd(const T & x)120 static bool IsIntNAdd(const T& x) {
121 return x.IsInt64Add();
122 }
123 template <typename T>
IsIntNMul(const T & x)124 static bool IsIntNMul(const T& x) {
125 return x.IsInt64Mul();
126 }
127
IntNAdd(MachineOperatorBuilder * machine)128 static const Operator* IntNAdd(MachineOperatorBuilder* machine) {
129 return machine->Int64Add();
130 }
131
ReplaceIntN(int64_t value)132 Reduction ReplaceIntN(int64_t value) { return r_->ReplaceInt64(value); }
ReduceWordNAnd(Node * node)133 Reduction ReduceWordNAnd(Node* node) { return r_->ReduceWord64And(node); }
ReduceIntNAdd(Node * node)134 Reduction ReduceIntNAdd(Node* node) { return r_->ReduceInt64Add(node); }
TryMatchWordNRor(Node * node)135 Reduction TryMatchWordNRor(Node* node) {
136 // TODO(nicohartmann@): Add a MachineOperatorReducer::TryMatchWord64Ror.
137 return r_->NoChange();
138 }
139
IntNConstant(int64_t value)140 Node* IntNConstant(int64_t value) { return r_->Int64Constant(value); }
UintNConstant(uint64_t value)141 Node* UintNConstant(uint64_t value) { return r_->Uint64Constant(value); }
WordNAnd(Node * lhs,Node * rhs)142 Node* WordNAnd(Node* lhs, Node* rhs) { return r_->Word64And(lhs, rhs); }
143
144 private:
145 MachineOperatorReducer* r_;
146 };
147
MachineOperatorReducer(Editor * editor,MachineGraph * mcgraph,bool allow_signalling_nan)148 MachineOperatorReducer::MachineOperatorReducer(Editor* editor,
149 MachineGraph* mcgraph,
150 bool allow_signalling_nan)
151 : AdvancedReducer(editor),
152 mcgraph_(mcgraph),
153 allow_signalling_nan_(allow_signalling_nan) {}
154
155 MachineOperatorReducer::~MachineOperatorReducer() = default;
156
157
Float32Constant(volatile float value)158 Node* MachineOperatorReducer::Float32Constant(volatile float value) {
159 return graph()->NewNode(common()->Float32Constant(value));
160 }
161
Float64Constant(volatile double value)162 Node* MachineOperatorReducer::Float64Constant(volatile double value) {
163 return mcgraph()->Float64Constant(value);
164 }
165
Int32Constant(int32_t value)166 Node* MachineOperatorReducer::Int32Constant(int32_t value) {
167 return mcgraph()->Int32Constant(value);
168 }
169
Int64Constant(int64_t value)170 Node* MachineOperatorReducer::Int64Constant(int64_t value) {
171 return graph()->NewNode(common()->Int64Constant(value));
172 }
173
Float64Mul(Node * lhs,Node * rhs)174 Node* MachineOperatorReducer::Float64Mul(Node* lhs, Node* rhs) {
175 return graph()->NewNode(machine()->Float64Mul(), lhs, rhs);
176 }
177
Float64PowHalf(Node * value)178 Node* MachineOperatorReducer::Float64PowHalf(Node* value) {
179 value =
180 graph()->NewNode(machine()->Float64Add(), Float64Constant(0.0), value);
181 Diamond d(graph(), common(),
182 graph()->NewNode(machine()->Float64LessThanOrEqual(), value,
183 Float64Constant(-V8_INFINITY)),
184 BranchHint::kFalse);
185 return d.Phi(MachineRepresentation::kFloat64, Float64Constant(V8_INFINITY),
186 graph()->NewNode(machine()->Float64Sqrt(), value));
187 }
188
Word32And(Node * lhs,Node * rhs)189 Node* MachineOperatorReducer::Word32And(Node* lhs, Node* rhs) {
190 Node* const node = graph()->NewNode(machine()->Word32And(), lhs, rhs);
191 Reduction const reduction = ReduceWord32And(node);
192 return reduction.Changed() ? reduction.replacement() : node;
193 }
194
Word32Sar(Node * lhs,uint32_t rhs)195 Node* MachineOperatorReducer::Word32Sar(Node* lhs, uint32_t rhs) {
196 if (rhs == 0) return lhs;
197 return graph()->NewNode(machine()->Word32Sar(), lhs, Uint32Constant(rhs));
198 }
199
Word32Shr(Node * lhs,uint32_t rhs)200 Node* MachineOperatorReducer::Word32Shr(Node* lhs, uint32_t rhs) {
201 if (rhs == 0) return lhs;
202 return graph()->NewNode(machine()->Word32Shr(), lhs, Uint32Constant(rhs));
203 }
204
Word32Equal(Node * lhs,Node * rhs)205 Node* MachineOperatorReducer::Word32Equal(Node* lhs, Node* rhs) {
206 return graph()->NewNode(machine()->Word32Equal(), lhs, rhs);
207 }
208
Word64And(Node * lhs,Node * rhs)209 Node* MachineOperatorReducer::Word64And(Node* lhs, Node* rhs) {
210 Node* const node = graph()->NewNode(machine()->Word64And(), lhs, rhs);
211 Reduction const reduction = ReduceWord64And(node);
212 return reduction.Changed() ? reduction.replacement() : node;
213 }
214
Int32Add(Node * lhs,Node * rhs)215 Node* MachineOperatorReducer::Int32Add(Node* lhs, Node* rhs) {
216 Node* const node = graph()->NewNode(machine()->Int32Add(), lhs, rhs);
217 Reduction const reduction = ReduceInt32Add(node);
218 return reduction.Changed() ? reduction.replacement() : node;
219 }
220
Int32Sub(Node * lhs,Node * rhs)221 Node* MachineOperatorReducer::Int32Sub(Node* lhs, Node* rhs) {
222 Node* const node = graph()->NewNode(machine()->Int32Sub(), lhs, rhs);
223 Reduction const reduction = ReduceInt32Sub(node);
224 return reduction.Changed() ? reduction.replacement() : node;
225 }
226
Int32Mul(Node * lhs,Node * rhs)227 Node* MachineOperatorReducer::Int32Mul(Node* lhs, Node* rhs) {
228 return graph()->NewNode(machine()->Int32Mul(), lhs, rhs);
229 }
230
Int32Div(Node * dividend,int32_t divisor)231 Node* MachineOperatorReducer::Int32Div(Node* dividend, int32_t divisor) {
232 DCHECK_NE(0, divisor);
233 DCHECK_NE(std::numeric_limits<int32_t>::min(), divisor);
234 base::MagicNumbersForDivision<uint32_t> const mag =
235 base::SignedDivisionByConstant(bit_cast<uint32_t>(divisor));
236 Node* quotient = graph()->NewNode(machine()->Int32MulHigh(), dividend,
237 Uint32Constant(mag.multiplier));
238 if (divisor > 0 && bit_cast<int32_t>(mag.multiplier) < 0) {
239 quotient = Int32Add(quotient, dividend);
240 } else if (divisor < 0 && bit_cast<int32_t>(mag.multiplier) > 0) {
241 quotient = Int32Sub(quotient, dividend);
242 }
243 return Int32Add(Word32Sar(quotient, mag.shift), Word32Shr(dividend, 31));
244 }
245
Uint32Div(Node * dividend,uint32_t divisor)246 Node* MachineOperatorReducer::Uint32Div(Node* dividend, uint32_t divisor) {
247 DCHECK_LT(0u, divisor);
248 // If the divisor is even, we can avoid using the expensive fixup by shifting
249 // the dividend upfront.
250 unsigned const shift = base::bits::CountTrailingZeros(divisor);
251 dividend = Word32Shr(dividend, shift);
252 divisor >>= shift;
253 // Compute the magic number for the (shifted) divisor.
254 base::MagicNumbersForDivision<uint32_t> const mag =
255 base::UnsignedDivisionByConstant(divisor, shift);
256 Node* quotient = graph()->NewNode(machine()->Uint32MulHigh(), dividend,
257 Uint32Constant(mag.multiplier));
258 if (mag.add) {
259 DCHECK_LE(1u, mag.shift);
260 quotient = Word32Shr(
261 Int32Add(Word32Shr(Int32Sub(dividend, quotient), 1), quotient),
262 mag.shift - 1);
263 } else {
264 quotient = Word32Shr(quotient, mag.shift);
265 }
266 return quotient;
267 }
268
TruncateInt64ToInt32(Node * value)269 Node* MachineOperatorReducer::TruncateInt64ToInt32(Node* value) {
270 Node* const node = graph()->NewNode(machine()->TruncateInt64ToInt32(), value);
271 Reduction const reduction = ReduceTruncateInt64ToInt32(node);
272 return reduction.Changed() ? reduction.replacement() : node;
273 }
274
275 // Perform constant folding and strength reduction on machine operators.
Reduce(Node * node)276 Reduction MachineOperatorReducer::Reduce(Node* node) {
277 switch (node->opcode()) {
278 case IrOpcode::kProjection:
279 return ReduceProjection(ProjectionIndexOf(node->op()), node->InputAt(0));
280 case IrOpcode::kWord32And:
281 return ReduceWord32And(node);
282 case IrOpcode::kWord64And:
283 return ReduceWord64And(node);
284 case IrOpcode::kWord32Or:
285 return ReduceWord32Or(node);
286 case IrOpcode::kWord64Or:
287 return ReduceWord64Or(node);
288 case IrOpcode::kWord32Xor:
289 return ReduceWord32Xor(node);
290 case IrOpcode::kWord64Xor:
291 return ReduceWord64Xor(node);
292 case IrOpcode::kWord32Shl:
293 return ReduceWord32Shl(node);
294 case IrOpcode::kWord64Shl:
295 return ReduceWord64Shl(node);
296 case IrOpcode::kWord32Shr:
297 return ReduceWord32Shr(node);
298 case IrOpcode::kWord64Shr:
299 return ReduceWord64Shr(node);
300 case IrOpcode::kWord32Sar:
301 return ReduceWord32Sar(node);
302 case IrOpcode::kWord64Sar:
303 return ReduceWord64Sar(node);
304 case IrOpcode::kWord32Ror: {
305 Int32BinopMatcher m(node);
306 if (m.right().Is(0)) return Replace(m.left().node()); // x ror 0 => x
307 if (m.IsFoldable()) { // K ror K => K (K stands for arbitrary constants)
308 return ReplaceInt32(base::bits::RotateRight32(
309 m.left().ResolvedValue(), m.right().ResolvedValue() & 31));
310 }
311 break;
312 }
313 case IrOpcode::kWord32Equal: {
314 return ReduceWord32Equal(node);
315 }
316 case IrOpcode::kWord64Equal: {
317 Int64BinopMatcher m(node);
318 if (m.IsFoldable()) { // K == K => K (K stands for arbitrary constants)
319 return ReplaceBool(m.left().ResolvedValue() ==
320 m.right().ResolvedValue());
321 }
322 if (m.left().IsInt64Sub() && m.right().Is(0)) { // x - y == 0 => x == y
323 Int64BinopMatcher msub(m.left().node());
324 node->ReplaceInput(0, msub.left().node());
325 node->ReplaceInput(1, msub.right().node());
326 return Changed(node);
327 }
328 // TODO(turbofan): fold HeapConstant, ExternalReference, pointer compares
329 if (m.LeftEqualsRight()) return ReplaceBool(true); // x == x => true
330 break;
331 }
332 case IrOpcode::kInt32Add:
333 return ReduceInt32Add(node);
334 case IrOpcode::kInt64Add:
335 return ReduceInt64Add(node);
336 case IrOpcode::kInt32Sub:
337 return ReduceInt32Sub(node);
338 case IrOpcode::kInt64Sub:
339 return ReduceInt64Sub(node);
340 case IrOpcode::kInt32Mul: {
341 Int32BinopMatcher m(node);
342 if (m.right().Is(0)) return Replace(m.right().node()); // x * 0 => 0
343 if (m.right().Is(1)) return Replace(m.left().node()); // x * 1 => x
344 if (m.IsFoldable()) { // K * K => K (K stands for arbitrary constants)
345 return ReplaceInt32(base::MulWithWraparound(m.left().ResolvedValue(),
346 m.right().ResolvedValue()));
347 }
348 if (m.right().Is(-1)) { // x * -1 => 0 - x
349 node->ReplaceInput(0, Int32Constant(0));
350 node->ReplaceInput(1, m.left().node());
351 NodeProperties::ChangeOp(node, machine()->Int32Sub());
352 return Changed(node);
353 }
354 if (m.right().IsPowerOf2()) { // x * 2^n => x << n
355 node->ReplaceInput(1, Int32Constant(base::bits::WhichPowerOfTwo(
356 m.right().ResolvedValue())));
357 NodeProperties::ChangeOp(node, machine()->Word32Shl());
358 return Changed(node).FollowedBy(ReduceWord32Shl(node));
359 }
360 // (x * Int32Constant(a)) * Int32Constant(b)) => x * Int32Constant(a * b)
361 if (m.right().HasResolvedValue() && m.left().IsInt32Mul()) {
362 Int32BinopMatcher n(m.left().node());
363 if (n.right().HasResolvedValue() && m.OwnsInput(m.left().node())) {
364 node->ReplaceInput(
365 1, Int32Constant(base::MulWithWraparound(
366 m.right().ResolvedValue(), n.right().ResolvedValue())));
367 node->ReplaceInput(0, n.left().node());
368 return Changed(node);
369 }
370 }
371 break;
372 }
373 case IrOpcode::kInt32MulWithOverflow: {
374 Int32BinopMatcher m(node);
375 if (m.right().Is(2)) {
376 node->ReplaceInput(1, m.left().node());
377 NodeProperties::ChangeOp(node, machine()->Int32AddWithOverflow());
378 return Changed(node);
379 }
380 if (m.right().Is(-1)) {
381 node->ReplaceInput(0, Int32Constant(0));
382 node->ReplaceInput(1, m.left().node());
383 NodeProperties::ChangeOp(node, machine()->Int32SubWithOverflow());
384 return Changed(node);
385 }
386 break;
387 }
388 case IrOpcode::kInt64Mul:
389 return ReduceInt64Mul(node);
390 case IrOpcode::kInt32Div:
391 return ReduceInt32Div(node);
392 case IrOpcode::kUint32Div:
393 return ReduceUint32Div(node);
394 case IrOpcode::kInt32Mod:
395 return ReduceInt32Mod(node);
396 case IrOpcode::kUint32Mod:
397 return ReduceUint32Mod(node);
398 case IrOpcode::kInt32LessThan: {
399 Int32BinopMatcher m(node);
400 if (m.IsFoldable()) { // K < K => K (K stands for arbitrary constants)
401 return ReplaceBool(m.left().ResolvedValue() <
402 m.right().ResolvedValue());
403 }
404 if (m.LeftEqualsRight()) return ReplaceBool(false); // x < x => false
405 if (m.left().IsWord32Or() && m.right().Is(0)) {
406 // (x | K) < 0 => true or (K | x) < 0 => true iff K < 0
407 Int32BinopMatcher mleftmatcher(m.left().node());
408 if (mleftmatcher.left().IsNegative() ||
409 mleftmatcher.right().IsNegative()) {
410 return ReplaceBool(true);
411 }
412 }
413 return ReduceWord32Comparisons(node);
414 }
415 case IrOpcode::kInt32LessThanOrEqual: {
416 Int32BinopMatcher m(node);
417 if (m.IsFoldable()) { // K <= K => K (K stands for arbitrary constants)
418 return ReplaceBool(m.left().ResolvedValue() <=
419 m.right().ResolvedValue());
420 }
421 if (m.LeftEqualsRight()) return ReplaceBool(true); // x <= x => true
422 return ReduceWord32Comparisons(node);
423 }
424 case IrOpcode::kUint32LessThan: {
425 Uint32BinopMatcher m(node);
426 if (m.left().Is(kMaxUInt32)) return ReplaceBool(false); // M < x => false
427 if (m.right().Is(0)) return ReplaceBool(false); // x < 0 => false
428 if (m.IsFoldable()) { // K < K => K (K stands for arbitrary constants)
429 return ReplaceBool(m.left().ResolvedValue() <
430 m.right().ResolvedValue());
431 }
432 if (m.LeftEqualsRight()) return ReplaceBool(false); // x < x => false
433 if (m.left().IsWord32Sar() && m.right().HasResolvedValue()) {
434 Int32BinopMatcher mleft(m.left().node());
435 if (mleft.right().HasResolvedValue()) {
436 // (x >> K) < C => x < (C << K)
437 // when C < (M >> K)
438 const uint32_t c = m.right().ResolvedValue();
439 const uint32_t k = mleft.right().ResolvedValue() & 0x1F;
440 if (c < static_cast<uint32_t>(kMaxInt >> k)) {
441 node->ReplaceInput(0, mleft.left().node());
442 node->ReplaceInput(1, Uint32Constant(c << k));
443 return Changed(node);
444 }
445 // TODO(turbofan): else the comparison is always true.
446 }
447 }
448 return ReduceWord32Comparisons(node);
449 }
450 case IrOpcode::kUint32LessThanOrEqual: {
451 Uint32BinopMatcher m(node);
452 if (m.left().Is(0)) return ReplaceBool(true); // 0 <= x => true
453 if (m.right().Is(kMaxUInt32)) return ReplaceBool(true); // x <= M => true
454 if (m.IsFoldable()) { // K <= K => K (K stands for arbitrary constants)
455 return ReplaceBool(m.left().ResolvedValue() <=
456 m.right().ResolvedValue());
457 }
458 if (m.LeftEqualsRight()) return ReplaceBool(true); // x <= x => true
459 return ReduceWord32Comparisons(node);
460 }
461 case IrOpcode::kFloat32Sub: {
462 Float32BinopMatcher m(node);
463 if (allow_signalling_nan_ && m.right().Is(0) &&
464 (std::copysign(1.0, m.right().ResolvedValue()) > 0)) {
465 return Replace(m.left().node()); // x - 0 => x
466 }
467 if (m.right().IsNaN()) { // x - NaN => NaN
468 // Do some calculation to make a signalling NaN quiet.
469 return ReplaceFloat32(m.right().ResolvedValue() -
470 m.right().ResolvedValue());
471 }
472 if (m.left().IsNaN()) { // NaN - x => NaN
473 // Do some calculation to make a signalling NaN quiet.
474 return ReplaceFloat32(m.left().ResolvedValue() -
475 m.left().ResolvedValue());
476 }
477 if (m.IsFoldable()) { // L - R => (L - R)
478 return ReplaceFloat32(m.left().ResolvedValue() -
479 m.right().ResolvedValue());
480 }
481 if (allow_signalling_nan_ && m.left().IsMinusZero()) {
482 // -0.0 - round_down(-0.0 - R) => round_up(R)
483 if (machine()->Float32RoundUp().IsSupported() &&
484 m.right().IsFloat32RoundDown()) {
485 if (m.right().InputAt(0)->opcode() == IrOpcode::kFloat32Sub) {
486 Float32BinopMatcher mright0(m.right().InputAt(0));
487 if (mright0.left().IsMinusZero()) {
488 return Replace(graph()->NewNode(machine()->Float32RoundUp().op(),
489 mright0.right().node()));
490 }
491 }
492 }
493 // -0.0 - R => -R
494 node->RemoveInput(0);
495 NodeProperties::ChangeOp(node, machine()->Float32Neg());
496 return Changed(node);
497 }
498 break;
499 }
500 case IrOpcode::kFloat64Add: {
501 Float64BinopMatcher m(node);
502 if (m.IsFoldable()) { // K + K => K (K stands for arbitrary constants)
503 return ReplaceFloat64(m.left().ResolvedValue() +
504 m.right().ResolvedValue());
505 }
506 break;
507 }
508 case IrOpcode::kFloat64Sub: {
509 Float64BinopMatcher m(node);
510 if (allow_signalling_nan_ && m.right().Is(0) &&
511 (Double(m.right().ResolvedValue()).Sign() > 0)) {
512 return Replace(m.left().node()); // x - 0 => x
513 }
514 if (m.right().IsNaN()) { // x - NaN => NaN
515 // Do some calculation to make a signalling NaN quiet.
516 return ReplaceFloat64(m.right().ResolvedValue() -
517 m.right().ResolvedValue());
518 }
519 if (m.left().IsNaN()) { // NaN - x => NaN
520 // Do some calculation to make a signalling NaN quiet.
521 return ReplaceFloat64(m.left().ResolvedValue() -
522 m.left().ResolvedValue());
523 }
524 if (m.IsFoldable()) { // L - R => (L - R)
525 return ReplaceFloat64(m.left().ResolvedValue() -
526 m.right().ResolvedValue());
527 }
528 if (allow_signalling_nan_ && m.left().IsMinusZero()) {
529 // -0.0 - round_down(-0.0 - R) => round_up(R)
530 if (machine()->Float64RoundUp().IsSupported() &&
531 m.right().IsFloat64RoundDown()) {
532 if (m.right().InputAt(0)->opcode() == IrOpcode::kFloat64Sub) {
533 Float64BinopMatcher mright0(m.right().InputAt(0));
534 if (mright0.left().IsMinusZero()) {
535 return Replace(graph()->NewNode(machine()->Float64RoundUp().op(),
536 mright0.right().node()));
537 }
538 }
539 }
540 // -0.0 - R => -R
541 node->RemoveInput(0);
542 NodeProperties::ChangeOp(node, machine()->Float64Neg());
543 return Changed(node);
544 }
545 break;
546 }
547 case IrOpcode::kFloat64Mul: {
548 Float64BinopMatcher m(node);
549 if (allow_signalling_nan_ && m.right().Is(1))
550 return Replace(m.left().node()); // x * 1.0 => x
551 if (m.right().Is(-1)) { // x * -1.0 => -0.0 - x
552 node->ReplaceInput(0, Float64Constant(-0.0));
553 node->ReplaceInput(1, m.left().node());
554 NodeProperties::ChangeOp(node, machine()->Float64Sub());
555 return Changed(node);
556 }
557 if (m.right().IsNaN()) { // x * NaN => NaN
558 // Do some calculation to make a signalling NaN quiet.
559 return ReplaceFloat64(m.right().ResolvedValue() -
560 m.right().ResolvedValue());
561 }
562 if (m.IsFoldable()) { // K * K => K (K stands for arbitrary constants)
563 return ReplaceFloat64(m.left().ResolvedValue() *
564 m.right().ResolvedValue());
565 }
566 if (m.right().Is(2)) { // x * 2.0 => x + x
567 node->ReplaceInput(1, m.left().node());
568 NodeProperties::ChangeOp(node, machine()->Float64Add());
569 return Changed(node);
570 }
571 break;
572 }
573 case IrOpcode::kFloat64Div: {
574 Float64BinopMatcher m(node);
575 if (allow_signalling_nan_ && m.right().Is(1))
576 return Replace(m.left().node()); // x / 1.0 => x
577 // TODO(ahaas): We could do x / 1.0 = x if we knew that x is not an sNaN.
578 if (m.right().IsNaN()) { // x / NaN => NaN
579 // Do some calculation to make a signalling NaN quiet.
580 return ReplaceFloat64(m.right().ResolvedValue() -
581 m.right().ResolvedValue());
582 }
583 if (m.left().IsNaN()) { // NaN / x => NaN
584 // Do some calculation to make a signalling NaN quiet.
585 return ReplaceFloat64(m.left().ResolvedValue() -
586 m.left().ResolvedValue());
587 }
588 if (m.IsFoldable()) { // K / K => K (K stands for arbitrary constants)
589 return ReplaceFloat64(
590 base::Divide(m.left().ResolvedValue(), m.right().ResolvedValue()));
591 }
592 if (allow_signalling_nan_ && m.right().Is(-1)) { // x / -1.0 => -x
593 node->RemoveInput(1);
594 NodeProperties::ChangeOp(node, machine()->Float64Neg());
595 return Changed(node);
596 }
597 if (m.right().IsNormal() && m.right().IsPositiveOrNegativePowerOf2()) {
598 // All reciprocals of non-denormal powers of two can be represented
599 // exactly, so division by power of two can be reduced to
600 // multiplication by reciprocal, with the same result.
601 node->ReplaceInput(1, Float64Constant(1.0 / m.right().ResolvedValue()));
602 NodeProperties::ChangeOp(node, machine()->Float64Mul());
603 return Changed(node);
604 }
605 break;
606 }
607 case IrOpcode::kFloat64Mod: {
608 Float64BinopMatcher m(node);
609 if (m.right().Is(0)) { // x % 0 => NaN
610 return ReplaceFloat64(std::numeric_limits<double>::quiet_NaN());
611 }
612 if (m.right().IsNaN()) { // x % NaN => NaN
613 return Replace(m.right().node());
614 }
615 if (m.left().IsNaN()) { // NaN % x => NaN
616 return Replace(m.left().node());
617 }
618 if (m.IsFoldable()) { // K % K => K (K stands for arbitrary constants)
619 return ReplaceFloat64(
620 Modulo(m.left().ResolvedValue(), m.right().ResolvedValue()));
621 }
622 break;
623 }
624 case IrOpcode::kFloat64Acos: {
625 Float64Matcher m(node->InputAt(0));
626 if (m.HasResolvedValue())
627 return ReplaceFloat64(base::ieee754::acos(m.ResolvedValue()));
628 break;
629 }
630 case IrOpcode::kFloat64Acosh: {
631 Float64Matcher m(node->InputAt(0));
632 if (m.HasResolvedValue())
633 return ReplaceFloat64(base::ieee754::acosh(m.ResolvedValue()));
634 break;
635 }
636 case IrOpcode::kFloat64Asin: {
637 Float64Matcher m(node->InputAt(0));
638 if (m.HasResolvedValue())
639 return ReplaceFloat64(base::ieee754::asin(m.ResolvedValue()));
640 break;
641 }
642 case IrOpcode::kFloat64Asinh: {
643 Float64Matcher m(node->InputAt(0));
644 if (m.HasResolvedValue())
645 return ReplaceFloat64(base::ieee754::asinh(m.ResolvedValue()));
646 break;
647 }
648 case IrOpcode::kFloat64Atan: {
649 Float64Matcher m(node->InputAt(0));
650 if (m.HasResolvedValue())
651 return ReplaceFloat64(base::ieee754::atan(m.ResolvedValue()));
652 break;
653 }
654 case IrOpcode::kFloat64Atanh: {
655 Float64Matcher m(node->InputAt(0));
656 if (m.HasResolvedValue())
657 return ReplaceFloat64(base::ieee754::atanh(m.ResolvedValue()));
658 break;
659 }
660 case IrOpcode::kFloat64Atan2: {
661 Float64BinopMatcher m(node);
662 if (m.right().IsNaN()) {
663 return Replace(m.right().node());
664 }
665 if (m.left().IsNaN()) {
666 return Replace(m.left().node());
667 }
668 if (m.IsFoldable()) {
669 return ReplaceFloat64(base::ieee754::atan2(m.left().ResolvedValue(),
670 m.right().ResolvedValue()));
671 }
672 break;
673 }
674 case IrOpcode::kFloat64Cbrt: {
675 Float64Matcher m(node->InputAt(0));
676 if (m.HasResolvedValue())
677 return ReplaceFloat64(base::ieee754::cbrt(m.ResolvedValue()));
678 break;
679 }
680 case IrOpcode::kFloat64Cos: {
681 Float64Matcher m(node->InputAt(0));
682 if (m.HasResolvedValue())
683 return ReplaceFloat64(base::ieee754::cos(m.ResolvedValue()));
684 break;
685 }
686 case IrOpcode::kFloat64Cosh: {
687 Float64Matcher m(node->InputAt(0));
688 if (m.HasResolvedValue())
689 return ReplaceFloat64(base::ieee754::cosh(m.ResolvedValue()));
690 break;
691 }
692 case IrOpcode::kFloat64Exp: {
693 Float64Matcher m(node->InputAt(0));
694 if (m.HasResolvedValue())
695 return ReplaceFloat64(base::ieee754::exp(m.ResolvedValue()));
696 break;
697 }
698 case IrOpcode::kFloat64Expm1: {
699 Float64Matcher m(node->InputAt(0));
700 if (m.HasResolvedValue())
701 return ReplaceFloat64(base::ieee754::expm1(m.ResolvedValue()));
702 break;
703 }
704 case IrOpcode::kFloat64Log: {
705 Float64Matcher m(node->InputAt(0));
706 if (m.HasResolvedValue())
707 return ReplaceFloat64(base::ieee754::log(m.ResolvedValue()));
708 break;
709 }
710 case IrOpcode::kFloat64Log1p: {
711 Float64Matcher m(node->InputAt(0));
712 if (m.HasResolvedValue())
713 return ReplaceFloat64(base::ieee754::log1p(m.ResolvedValue()));
714 break;
715 }
716 case IrOpcode::kFloat64Log10: {
717 Float64Matcher m(node->InputAt(0));
718 if (m.HasResolvedValue())
719 return ReplaceFloat64(base::ieee754::log10(m.ResolvedValue()));
720 break;
721 }
722 case IrOpcode::kFloat64Log2: {
723 Float64Matcher m(node->InputAt(0));
724 if (m.HasResolvedValue())
725 return ReplaceFloat64(base::ieee754::log2(m.ResolvedValue()));
726 break;
727 }
728 case IrOpcode::kFloat64Pow: {
729 Float64BinopMatcher m(node);
730 if (m.IsFoldable()) {
731 return ReplaceFloat64(base::ieee754::pow(m.left().ResolvedValue(),
732 m.right().ResolvedValue()));
733 } else if (m.right().Is(0.0)) { // x ** +-0.0 => 1.0
734 return ReplaceFloat64(1.0);
735 } else if (m.right().Is(-2.0)) { // x ** -2.0 => 1 / (x * x)
736 node->ReplaceInput(0, Float64Constant(1.0));
737 node->ReplaceInput(1, Float64Mul(m.left().node(), m.left().node()));
738 NodeProperties::ChangeOp(node, machine()->Float64Div());
739 return Changed(node);
740 } else if (m.right().Is(2.0)) { // x ** 2.0 => x * x
741 node->ReplaceInput(1, m.left().node());
742 NodeProperties::ChangeOp(node, machine()->Float64Mul());
743 return Changed(node);
744 } else if (m.right().Is(-0.5)) {
745 // x ** 0.5 => 1 / (if x <= -Infinity then Infinity else sqrt(0.0 + x))
746 node->ReplaceInput(0, Float64Constant(1.0));
747 node->ReplaceInput(1, Float64PowHalf(m.left().node()));
748 NodeProperties::ChangeOp(node, machine()->Float64Div());
749 return Changed(node);
750 } else if (m.right().Is(0.5)) {
751 // x ** 0.5 => if x <= -Infinity then Infinity else sqrt(0.0 + x)
752 return Replace(Float64PowHalf(m.left().node()));
753 }
754 break;
755 }
756 case IrOpcode::kFloat64Sin: {
757 Float64Matcher m(node->InputAt(0));
758 if (m.HasResolvedValue())
759 return ReplaceFloat64(base::ieee754::sin(m.ResolvedValue()));
760 break;
761 }
762 case IrOpcode::kFloat64Sinh: {
763 Float64Matcher m(node->InputAt(0));
764 if (m.HasResolvedValue())
765 return ReplaceFloat64(base::ieee754::sinh(m.ResolvedValue()));
766 break;
767 }
768 case IrOpcode::kFloat64Tan: {
769 Float64Matcher m(node->InputAt(0));
770 if (m.HasResolvedValue())
771 return ReplaceFloat64(base::ieee754::tan(m.ResolvedValue()));
772 break;
773 }
774 case IrOpcode::kFloat64Tanh: {
775 Float64Matcher m(node->InputAt(0));
776 if (m.HasResolvedValue())
777 return ReplaceFloat64(base::ieee754::tanh(m.ResolvedValue()));
778 break;
779 }
780 case IrOpcode::kChangeFloat32ToFloat64: {
781 Float32Matcher m(node->InputAt(0));
782 if (m.HasResolvedValue()) {
783 if (!allow_signalling_nan_ && std::isnan(m.ResolvedValue())) {
784 // Do some calculation to make guarantee the value is a quiet NaN.
785 return ReplaceFloat64(m.ResolvedValue() + m.ResolvedValue());
786 }
787 return ReplaceFloat64(m.ResolvedValue());
788 }
789 break;
790 }
791 case IrOpcode::kChangeFloat64ToInt32: {
792 Float64Matcher m(node->InputAt(0));
793 if (m.HasResolvedValue())
794 return ReplaceInt32(FastD2IChecked(m.ResolvedValue()));
795 if (m.IsChangeInt32ToFloat64()) return Replace(m.node()->InputAt(0));
796 break;
797 }
798 case IrOpcode::kChangeFloat64ToInt64: {
799 Float64Matcher m(node->InputAt(0));
800 if (m.HasResolvedValue())
801 return ReplaceInt64(static_cast<int64_t>(m.ResolvedValue()));
802 if (m.IsChangeInt64ToFloat64()) return Replace(m.node()->InputAt(0));
803 break;
804 }
805 case IrOpcode::kChangeFloat64ToUint32: {
806 Float64Matcher m(node->InputAt(0));
807 if (m.HasResolvedValue())
808 return ReplaceInt32(FastD2UI(m.ResolvedValue()));
809 if (m.IsChangeUint32ToFloat64()) return Replace(m.node()->InputAt(0));
810 break;
811 }
812 case IrOpcode::kChangeInt32ToFloat64: {
813 Int32Matcher m(node->InputAt(0));
814 if (m.HasResolvedValue())
815 return ReplaceFloat64(FastI2D(m.ResolvedValue()));
816 break;
817 }
818 case IrOpcode::kBitcastWord32ToWord64: {
819 Int32Matcher m(node->InputAt(0));
820 if (m.HasResolvedValue()) return ReplaceInt64(m.ResolvedValue());
821 break;
822 }
823 case IrOpcode::kChangeInt32ToInt64: {
824 Int32Matcher m(node->InputAt(0));
825 if (m.HasResolvedValue()) return ReplaceInt64(m.ResolvedValue());
826 break;
827 }
828 case IrOpcode::kChangeInt64ToFloat64: {
829 Int64Matcher m(node->InputAt(0));
830 if (m.HasResolvedValue())
831 return ReplaceFloat64(static_cast<double>(m.ResolvedValue()));
832 if (m.IsChangeFloat64ToInt64()) return Replace(m.node()->InputAt(0));
833 break;
834 }
835 case IrOpcode::kChangeUint32ToFloat64: {
836 Uint32Matcher m(node->InputAt(0));
837 if (m.HasResolvedValue())
838 return ReplaceFloat64(FastUI2D(m.ResolvedValue()));
839 break;
840 }
841 case IrOpcode::kChangeUint32ToUint64: {
842 Uint32Matcher m(node->InputAt(0));
843 if (m.HasResolvedValue())
844 return ReplaceInt64(static_cast<uint64_t>(m.ResolvedValue()));
845 break;
846 }
847 case IrOpcode::kTruncateFloat64ToWord32: {
848 Float64Matcher m(node->InputAt(0));
849 if (m.HasResolvedValue())
850 return ReplaceInt32(DoubleToInt32(m.ResolvedValue()));
851 if (m.IsChangeInt32ToFloat64()) return Replace(m.node()->InputAt(0));
852 return NoChange();
853 }
854 case IrOpcode::kTruncateInt64ToInt32:
855 return ReduceTruncateInt64ToInt32(node);
856 case IrOpcode::kTruncateFloat64ToFloat32: {
857 Float64Matcher m(node->InputAt(0));
858 if (m.HasResolvedValue()) {
859 if (!allow_signalling_nan_ && std::isnan(m.ResolvedValue())) {
860 // Do some calculation to make guarantee the value is a quiet NaN.
861 return ReplaceFloat32(
862 DoubleToFloat32(m.ResolvedValue() + m.ResolvedValue()));
863 }
864 return ReplaceFloat32(DoubleToFloat32(m.ResolvedValue()));
865 }
866 if (allow_signalling_nan_ && m.IsChangeFloat32ToFloat64())
867 return Replace(m.node()->InputAt(0));
868 break;
869 }
870 case IrOpcode::kRoundFloat64ToInt32: {
871 Float64Matcher m(node->InputAt(0));
872 if (m.HasResolvedValue()) {
873 return ReplaceInt32(DoubleToInt32(m.ResolvedValue()));
874 }
875 if (m.IsChangeInt32ToFloat64()) return Replace(m.node()->InputAt(0));
876 break;
877 }
878 case IrOpcode::kFloat64InsertLowWord32:
879 return ReduceFloat64InsertLowWord32(node);
880 case IrOpcode::kFloat64InsertHighWord32:
881 return ReduceFloat64InsertHighWord32(node);
882 case IrOpcode::kStore:
883 case IrOpcode::kUnalignedStore:
884 return ReduceStore(node);
885 case IrOpcode::kFloat64Equal:
886 case IrOpcode::kFloat64LessThan:
887 case IrOpcode::kFloat64LessThanOrEqual:
888 return ReduceFloat64Compare(node);
889 case IrOpcode::kFloat64RoundDown:
890 return ReduceFloat64RoundDown(node);
891 case IrOpcode::kBitcastTaggedToWord:
892 case IrOpcode::kBitcastTaggedToWordForTagAndSmiBits: {
893 NodeMatcher m(node->InputAt(0));
894 if (m.IsBitcastWordToTaggedSigned()) {
895 RelaxEffectsAndControls(node);
896 return Replace(m.InputAt(0));
897 }
898 break;
899 }
900 case IrOpcode::kBranch:
901 case IrOpcode::kDeoptimizeIf:
902 case IrOpcode::kDeoptimizeUnless:
903 case IrOpcode::kTrapIf:
904 case IrOpcode::kTrapUnless:
905 return ReduceConditional(node);
906 case IrOpcode::kInt64LessThan: {
907 Int64BinopMatcher m(node);
908 if (m.IsFoldable()) { // K < K => K (K stands for arbitrary constants)
909 return ReplaceBool(m.left().ResolvedValue() <
910 m.right().ResolvedValue());
911 }
912 return ReduceWord64Comparisons(node);
913 }
914 case IrOpcode::kInt64LessThanOrEqual: {
915 Int64BinopMatcher m(node);
916 if (m.IsFoldable()) { // K <= K => K (K stands for arbitrary constants)
917 return ReplaceBool(m.left().ResolvedValue() <=
918 m.right().ResolvedValue());
919 }
920 return ReduceWord64Comparisons(node);
921 }
922 case IrOpcode::kUint64LessThan: {
923 Uint64BinopMatcher m(node);
924 if (m.IsFoldable()) { // K < K => K (K stands for arbitrary constants)
925 return ReplaceBool(m.left().ResolvedValue() <
926 m.right().ResolvedValue());
927 }
928 return ReduceWord64Comparisons(node);
929 }
930 case IrOpcode::kUint64LessThanOrEqual: {
931 Uint64BinopMatcher m(node);
932 if (m.IsFoldable()) { // K <= K => K (K stands for arbitrary constants)
933 return ReplaceBool(m.left().ResolvedValue() <=
934 m.right().ResolvedValue());
935 }
936 return ReduceWord64Comparisons(node);
937 }
938 default:
939 break;
940 }
941 return NoChange();
942 }
943
ReduceTruncateInt64ToInt32(Node * node)944 Reduction MachineOperatorReducer::ReduceTruncateInt64ToInt32(Node* node) {
945 Int64Matcher m(node->InputAt(0));
946 if (m.HasResolvedValue())
947 return ReplaceInt32(static_cast<int32_t>(m.ResolvedValue()));
948 if (m.IsChangeInt32ToInt64()) return Replace(m.node()->InputAt(0));
949 return NoChange();
950 }
951
ReduceInt32Add(Node * node)952 Reduction MachineOperatorReducer::ReduceInt32Add(Node* node) {
953 DCHECK_EQ(IrOpcode::kInt32Add, node->opcode());
954 Int32BinopMatcher m(node);
955 if (m.right().Is(0)) return Replace(m.left().node()); // x + 0 => x
956 if (m.IsFoldable()) { // K + K => K (K stands for arbitrary constants)
957 return ReplaceInt32(base::AddWithWraparound(m.left().ResolvedValue(),
958 m.right().ResolvedValue()));
959 }
960 if (m.left().IsInt32Sub()) {
961 Int32BinopMatcher mleft(m.left().node());
962 if (mleft.left().Is(0)) { // (0 - x) + y => y - x
963 node->ReplaceInput(0, m.right().node());
964 node->ReplaceInput(1, mleft.right().node());
965 NodeProperties::ChangeOp(node, machine()->Int32Sub());
966 return Changed(node).FollowedBy(ReduceInt32Sub(node));
967 }
968 }
969 if (m.right().IsInt32Sub()) {
970 Int32BinopMatcher mright(m.right().node());
971 if (mright.left().Is(0)) { // y + (0 - x) => y - x
972 node->ReplaceInput(1, mright.right().node());
973 NodeProperties::ChangeOp(node, machine()->Int32Sub());
974 return Changed(node).FollowedBy(ReduceInt32Sub(node));
975 }
976 }
977 // (x + Int32Constant(a)) + Int32Constant(b)) => x + Int32Constant(a + b)
978 if (m.right().HasResolvedValue() && m.left().IsInt32Add()) {
979 Int32BinopMatcher n(m.left().node());
980 if (n.right().HasResolvedValue() && m.OwnsInput(m.left().node())) {
981 node->ReplaceInput(
982 1, Int32Constant(base::AddWithWraparound(m.right().ResolvedValue(),
983 n.right().ResolvedValue())));
984 node->ReplaceInput(0, n.left().node());
985 return Changed(node);
986 }
987 }
988
989 return NoChange();
990 }
991
ReduceInt64Add(Node * node)992 Reduction MachineOperatorReducer::ReduceInt64Add(Node* node) {
993 DCHECK_EQ(IrOpcode::kInt64Add, node->opcode());
994 Int64BinopMatcher m(node);
995 if (m.right().Is(0)) return Replace(m.left().node()); // x + 0 => 0
996 if (m.IsFoldable()) {
997 return ReplaceInt64(base::AddWithWraparound(m.left().ResolvedValue(),
998 m.right().ResolvedValue()));
999 }
1000 // (x + Int64Constant(a)) + Int64Constant(b)) => x + Int64Constant(a + b)
1001 if (m.right().HasResolvedValue() && m.left().IsInt64Add()) {
1002 Int64BinopMatcher n(m.left().node());
1003 if (n.right().HasResolvedValue() && m.OwnsInput(m.left().node())) {
1004 node->ReplaceInput(
1005 1, Int64Constant(base::AddWithWraparound(m.right().ResolvedValue(),
1006 n.right().ResolvedValue())));
1007 node->ReplaceInput(0, n.left().node());
1008 return Changed(node);
1009 }
1010 }
1011 return NoChange();
1012 }
1013
ReduceInt32Sub(Node * node)1014 Reduction MachineOperatorReducer::ReduceInt32Sub(Node* node) {
1015 DCHECK_EQ(IrOpcode::kInt32Sub, node->opcode());
1016 Int32BinopMatcher m(node);
1017 if (m.right().Is(0)) return Replace(m.left().node()); // x - 0 => x
1018 if (m.IsFoldable()) { // K - K => K (K stands for arbitrary constants)
1019 return ReplaceInt32(base::SubWithWraparound(m.left().ResolvedValue(),
1020 m.right().ResolvedValue()));
1021 }
1022 if (m.LeftEqualsRight()) return ReplaceInt32(0); // x - x => 0
1023 if (m.right().HasResolvedValue()) { // x - K => x + -K
1024 node->ReplaceInput(
1025 1,
1026 Int32Constant(base::NegateWithWraparound(m.right().ResolvedValue())));
1027 NodeProperties::ChangeOp(node, machine()->Int32Add());
1028 return Changed(node).FollowedBy(ReduceInt32Add(node));
1029 }
1030 return NoChange();
1031 }
1032
ReduceInt64Sub(Node * node)1033 Reduction MachineOperatorReducer::ReduceInt64Sub(Node* node) {
1034 DCHECK_EQ(IrOpcode::kInt64Sub, node->opcode());
1035 Int64BinopMatcher m(node);
1036 if (m.right().Is(0)) return Replace(m.left().node()); // x - 0 => x
1037 if (m.IsFoldable()) { // K - K => K (K stands for arbitrary constants)
1038 return ReplaceInt64(base::SubWithWraparound(m.left().ResolvedValue(),
1039 m.right().ResolvedValue()));
1040 }
1041 if (m.LeftEqualsRight()) return Replace(Int64Constant(0)); // x - x => 0
1042 if (m.right().HasResolvedValue()) { // x - K => x + -K
1043 node->ReplaceInput(
1044 1,
1045 Int64Constant(base::NegateWithWraparound(m.right().ResolvedValue())));
1046 NodeProperties::ChangeOp(node, machine()->Int64Add());
1047 return Changed(node).FollowedBy(ReduceInt64Add(node));
1048 }
1049 return NoChange();
1050 }
1051
ReduceInt64Mul(Node * node)1052 Reduction MachineOperatorReducer::ReduceInt64Mul(Node* node) {
1053 DCHECK_EQ(IrOpcode::kInt64Mul, node->opcode());
1054 Int64BinopMatcher m(node);
1055 if (m.right().Is(0)) return Replace(m.right().node()); // x * 0 => 0
1056 if (m.right().Is(1)) return Replace(m.left().node()); // x * 1 => x
1057 if (m.IsFoldable()) { // K * K => K (K stands for arbitrary constants)
1058 return ReplaceInt64(base::MulWithWraparound(m.left().ResolvedValue(),
1059 m.right().ResolvedValue()));
1060 }
1061 if (m.right().Is(-1)) { // x * -1 => 0 - x
1062 node->ReplaceInput(0, Int64Constant(0));
1063 node->ReplaceInput(1, m.left().node());
1064 NodeProperties::ChangeOp(node, machine()->Int64Sub());
1065 return Changed(node);
1066 }
1067 if (m.right().IsPowerOf2()) { // x * 2^n => x << n
1068 node->ReplaceInput(
1069 1,
1070 Int64Constant(base::bits::WhichPowerOfTwo(m.right().ResolvedValue())));
1071 NodeProperties::ChangeOp(node, machine()->Word64Shl());
1072 return Changed(node).FollowedBy(ReduceWord64Shl(node));
1073 }
1074 // (x * Int64Constant(a)) * Int64Constant(b)) => x * Int64Constant(a * b)
1075 if (m.right().HasResolvedValue() && m.left().IsInt64Mul()) {
1076 Int64BinopMatcher n(m.left().node());
1077 if (n.right().HasResolvedValue() && m.OwnsInput(m.left().node())) {
1078 node->ReplaceInput(
1079 1, Int64Constant(base::MulWithWraparound(m.right().ResolvedValue(),
1080 n.right().ResolvedValue())));
1081 node->ReplaceInput(0, n.left().node());
1082 return Changed(node);
1083 }
1084 }
1085 return NoChange();
1086 }
1087
ReduceInt32Div(Node * node)1088 Reduction MachineOperatorReducer::ReduceInt32Div(Node* node) {
1089 Int32BinopMatcher m(node);
1090 if (m.left().Is(0)) return Replace(m.left().node()); // 0 / x => 0
1091 if (m.right().Is(0)) return Replace(m.right().node()); // x / 0 => 0
1092 if (m.right().Is(1)) return Replace(m.left().node()); // x / 1 => x
1093 if (m.IsFoldable()) { // K / K => K (K stands for arbitrary constants)
1094 return ReplaceInt32(base::bits::SignedDiv32(m.left().ResolvedValue(),
1095 m.right().ResolvedValue()));
1096 }
1097 if (m.LeftEqualsRight()) { // x / x => x != 0
1098 Node* const zero = Int32Constant(0);
1099 return Replace(Word32Equal(Word32Equal(m.left().node(), zero), zero));
1100 }
1101 if (m.right().Is(-1)) { // x / -1 => 0 - x
1102 node->ReplaceInput(0, Int32Constant(0));
1103 node->ReplaceInput(1, m.left().node());
1104 node->TrimInputCount(2);
1105 NodeProperties::ChangeOp(node, machine()->Int32Sub());
1106 return Changed(node);
1107 }
1108 if (m.right().HasResolvedValue()) {
1109 int32_t const divisor = m.right().ResolvedValue();
1110 Node* const dividend = m.left().node();
1111 Node* quotient = dividend;
1112 if (base::bits::IsPowerOfTwo(Abs(divisor))) {
1113 uint32_t const shift = base::bits::WhichPowerOfTwo(Abs(divisor));
1114 DCHECK_NE(0u, shift);
1115 if (shift > 1) {
1116 quotient = Word32Sar(quotient, 31);
1117 }
1118 quotient = Int32Add(Word32Shr(quotient, 32u - shift), dividend);
1119 quotient = Word32Sar(quotient, shift);
1120 } else {
1121 quotient = Int32Div(quotient, Abs(divisor));
1122 }
1123 if (divisor < 0) {
1124 node->ReplaceInput(0, Int32Constant(0));
1125 node->ReplaceInput(1, quotient);
1126 node->TrimInputCount(2);
1127 NodeProperties::ChangeOp(node, machine()->Int32Sub());
1128 return Changed(node);
1129 }
1130 return Replace(quotient);
1131 }
1132 return NoChange();
1133 }
1134
ReduceUint32Div(Node * node)1135 Reduction MachineOperatorReducer::ReduceUint32Div(Node* node) {
1136 Uint32BinopMatcher m(node);
1137 if (m.left().Is(0)) return Replace(m.left().node()); // 0 / x => 0
1138 if (m.right().Is(0)) return Replace(m.right().node()); // x / 0 => 0
1139 if (m.right().Is(1)) return Replace(m.left().node()); // x / 1 => x
1140 if (m.IsFoldable()) { // K / K => K (K stands for arbitrary constants)
1141 return ReplaceUint32(base::bits::UnsignedDiv32(m.left().ResolvedValue(),
1142 m.right().ResolvedValue()));
1143 }
1144 if (m.LeftEqualsRight()) { // x / x => x != 0
1145 Node* const zero = Int32Constant(0);
1146 return Replace(Word32Equal(Word32Equal(m.left().node(), zero), zero));
1147 }
1148 if (m.right().HasResolvedValue()) {
1149 Node* const dividend = m.left().node();
1150 uint32_t const divisor = m.right().ResolvedValue();
1151 if (base::bits::IsPowerOfTwo(divisor)) { // x / 2^n => x >> n
1152 node->ReplaceInput(1, Uint32Constant(base::bits::WhichPowerOfTwo(
1153 m.right().ResolvedValue())));
1154 node->TrimInputCount(2);
1155 NodeProperties::ChangeOp(node, machine()->Word32Shr());
1156 return Changed(node);
1157 } else {
1158 return Replace(Uint32Div(dividend, divisor));
1159 }
1160 }
1161 return NoChange();
1162 }
1163
ReduceInt32Mod(Node * node)1164 Reduction MachineOperatorReducer::ReduceInt32Mod(Node* node) {
1165 Int32BinopMatcher m(node);
1166 if (m.left().Is(0)) return Replace(m.left().node()); // 0 % x => 0
1167 if (m.right().Is(0)) return Replace(m.right().node()); // x % 0 => 0
1168 if (m.right().Is(1)) return ReplaceInt32(0); // x % 1 => 0
1169 if (m.right().Is(-1)) return ReplaceInt32(0); // x % -1 => 0
1170 if (m.LeftEqualsRight()) return ReplaceInt32(0); // x % x => 0
1171 if (m.IsFoldable()) { // K % K => K (K stands for arbitrary constants)
1172 return ReplaceInt32(base::bits::SignedMod32(m.left().ResolvedValue(),
1173 m.right().ResolvedValue()));
1174 }
1175 if (m.right().HasResolvedValue()) {
1176 Node* const dividend = m.left().node();
1177 uint32_t const divisor = Abs(m.right().ResolvedValue());
1178 if (base::bits::IsPowerOfTwo(divisor)) {
1179 uint32_t const mask = divisor - 1;
1180 Node* const zero = Int32Constant(0);
1181 Diamond d(graph(), common(),
1182 graph()->NewNode(machine()->Int32LessThan(), dividend, zero),
1183 BranchHint::kFalse);
1184 return Replace(
1185 d.Phi(MachineRepresentation::kWord32,
1186 Int32Sub(zero, Word32And(Int32Sub(zero, dividend), mask)),
1187 Word32And(dividend, mask)));
1188 } else {
1189 Node* quotient = Int32Div(dividend, divisor);
1190 DCHECK_EQ(dividend, node->InputAt(0));
1191 node->ReplaceInput(1, Int32Mul(quotient, Int32Constant(divisor)));
1192 node->TrimInputCount(2);
1193 NodeProperties::ChangeOp(node, machine()->Int32Sub());
1194 }
1195 return Changed(node);
1196 }
1197 return NoChange();
1198 }
1199
ReduceUint32Mod(Node * node)1200 Reduction MachineOperatorReducer::ReduceUint32Mod(Node* node) {
1201 Uint32BinopMatcher m(node);
1202 if (m.left().Is(0)) return Replace(m.left().node()); // 0 % x => 0
1203 if (m.right().Is(0)) return Replace(m.right().node()); // x % 0 => 0
1204 if (m.right().Is(1)) return ReplaceUint32(0); // x % 1 => 0
1205 if (m.LeftEqualsRight()) return ReplaceInt32(0); // x % x => 0
1206 if (m.IsFoldable()) { // K % K => K (K stands for arbitrary constants)
1207 return ReplaceUint32(base::bits::UnsignedMod32(m.left().ResolvedValue(),
1208 m.right().ResolvedValue()));
1209 }
1210 if (m.right().HasResolvedValue()) {
1211 Node* const dividend = m.left().node();
1212 uint32_t const divisor = m.right().ResolvedValue();
1213 if (base::bits::IsPowerOfTwo(divisor)) { // x % 2^n => x & 2^n-1
1214 node->ReplaceInput(1, Uint32Constant(m.right().ResolvedValue() - 1));
1215 node->TrimInputCount(2);
1216 NodeProperties::ChangeOp(node, machine()->Word32And());
1217 } else {
1218 Node* quotient = Uint32Div(dividend, divisor);
1219 DCHECK_EQ(dividend, node->InputAt(0));
1220 node->ReplaceInput(1, Int32Mul(quotient, Uint32Constant(divisor)));
1221 node->TrimInputCount(2);
1222 NodeProperties::ChangeOp(node, machine()->Int32Sub());
1223 }
1224 return Changed(node);
1225 }
1226 return NoChange();
1227 }
1228
ReduceStore(Node * node)1229 Reduction MachineOperatorReducer::ReduceStore(Node* node) {
1230 NodeMatcher nm(node);
1231 MachineRepresentation rep;
1232 int value_input;
1233 if (nm.IsStore()) {
1234 rep = StoreRepresentationOf(node->op()).representation();
1235 value_input = 2;
1236 } else {
1237 DCHECK(nm.IsUnalignedStore());
1238 rep = UnalignedStoreRepresentationOf(node->op());
1239 value_input = 2;
1240 }
1241
1242 Node* const value = node->InputAt(value_input);
1243
1244 switch (value->opcode()) {
1245 case IrOpcode::kWord32And: {
1246 Uint32BinopMatcher m(value);
1247 if (m.right().HasResolvedValue() &&
1248 ((rep == MachineRepresentation::kWord8 &&
1249 (m.right().ResolvedValue() & 0xFF) == 0xFF) ||
1250 (rep == MachineRepresentation::kWord16 &&
1251 (m.right().ResolvedValue() & 0xFFFF) == 0xFFFF))) {
1252 node->ReplaceInput(value_input, m.left().node());
1253 return Changed(node);
1254 }
1255 break;
1256 }
1257 case IrOpcode::kWord32Sar: {
1258 Int32BinopMatcher m(value);
1259 if (m.left().IsWord32Shl() && ((rep == MachineRepresentation::kWord8 &&
1260 m.right().IsInRange(1, 24)) ||
1261 (rep == MachineRepresentation::kWord16 &&
1262 m.right().IsInRange(1, 16)))) {
1263 Int32BinopMatcher mleft(m.left().node());
1264 if (mleft.right().Is(m.right().ResolvedValue())) {
1265 node->ReplaceInput(value_input, mleft.left().node());
1266 return Changed(node);
1267 }
1268 }
1269 break;
1270 }
1271 default:
1272 break;
1273 }
1274 return NoChange();
1275 }
1276
ReduceProjection(size_t index,Node * node)1277 Reduction MachineOperatorReducer::ReduceProjection(size_t index, Node* node) {
1278 switch (node->opcode()) {
1279 case IrOpcode::kInt32AddWithOverflow: {
1280 DCHECK(index == 0 || index == 1);
1281 Int32BinopMatcher m(node);
1282 if (m.IsFoldable()) {
1283 int32_t val;
1284 bool ovf = base::bits::SignedAddOverflow32(
1285 m.left().ResolvedValue(), m.right().ResolvedValue(), &val);
1286 return ReplaceInt32(index == 0 ? val : ovf);
1287 }
1288 if (m.right().Is(0)) {
1289 return Replace(index == 0 ? m.left().node() : m.right().node());
1290 }
1291 break;
1292 }
1293 case IrOpcode::kInt32SubWithOverflow: {
1294 DCHECK(index == 0 || index == 1);
1295 Int32BinopMatcher m(node);
1296 if (m.IsFoldable()) {
1297 int32_t val;
1298 bool ovf = base::bits::SignedSubOverflow32(
1299 m.left().ResolvedValue(), m.right().ResolvedValue(), &val);
1300 return ReplaceInt32(index == 0 ? val : ovf);
1301 }
1302 if (m.right().Is(0)) {
1303 return Replace(index == 0 ? m.left().node() : m.right().node());
1304 }
1305 break;
1306 }
1307 case IrOpcode::kInt32MulWithOverflow: {
1308 DCHECK(index == 0 || index == 1);
1309 Int32BinopMatcher m(node);
1310 if (m.IsFoldable()) {
1311 int32_t val;
1312 bool ovf = base::bits::SignedMulOverflow32(
1313 m.left().ResolvedValue(), m.right().ResolvedValue(), &val);
1314 return ReplaceInt32(index == 0 ? val : ovf);
1315 }
1316 if (m.right().Is(0)) {
1317 return Replace(m.right().node());
1318 }
1319 if (m.right().Is(1)) {
1320 return index == 0 ? Replace(m.left().node()) : ReplaceInt32(0);
1321 }
1322 break;
1323 }
1324 default:
1325 break;
1326 }
1327 return NoChange();
1328 }
1329
ReduceWord32Comparisons(Node * node)1330 Reduction MachineOperatorReducer::ReduceWord32Comparisons(Node* node) {
1331 DCHECK(node->opcode() == IrOpcode::kInt32LessThan ||
1332 node->opcode() == IrOpcode::kInt32LessThanOrEqual ||
1333 node->opcode() == IrOpcode::kUint32LessThan ||
1334 node->opcode() == IrOpcode::kUint32LessThanOrEqual);
1335 Int32BinopMatcher m(node);
1336 // (x >>> K) < (y >>> K) => x < y if only zeros shifted out
1337 if (m.left().op() == machine()->Word32SarShiftOutZeros() &&
1338 m.right().op() == machine()->Word32SarShiftOutZeros()) {
1339 Int32BinopMatcher mleft(m.left().node());
1340 Int32BinopMatcher mright(m.right().node());
1341 if (mleft.right().HasResolvedValue() &&
1342 mright.right().Is(mleft.right().ResolvedValue())) {
1343 node->ReplaceInput(0, mleft.left().node());
1344 node->ReplaceInput(1, mright.left().node());
1345 return Changed(node);
1346 }
1347 }
1348 return NoChange();
1349 }
1350
Map64To32Comparison(const Operator * op,bool sign_extended)1351 const Operator* MachineOperatorReducer::Map64To32Comparison(
1352 const Operator* op, bool sign_extended) {
1353 switch (op->opcode()) {
1354 case IrOpcode::kInt64LessThan:
1355 return sign_extended ? machine()->Int32LessThan()
1356 : machine()->Uint32LessThan();
1357 case IrOpcode::kInt64LessThanOrEqual:
1358 return sign_extended ? machine()->Int32LessThanOrEqual()
1359 : machine()->Uint32LessThanOrEqual();
1360 case IrOpcode::kUint64LessThan:
1361 return machine()->Uint32LessThan();
1362 case IrOpcode::kUint64LessThanOrEqual:
1363 return machine()->Uint32LessThanOrEqual();
1364 default:
1365 UNREACHABLE();
1366 }
1367 }
1368
ReduceWord64Comparisons(Node * node)1369 Reduction MachineOperatorReducer::ReduceWord64Comparisons(Node* node) {
1370 DCHECK(node->opcode() == IrOpcode::kInt64LessThan ||
1371 node->opcode() == IrOpcode::kInt64LessThanOrEqual ||
1372 node->opcode() == IrOpcode::kUint64LessThan ||
1373 node->opcode() == IrOpcode::kUint64LessThanOrEqual);
1374 Int64BinopMatcher m(node);
1375
1376 bool sign_extended =
1377 m.left().IsChangeInt32ToInt64() && m.right().IsChangeInt32ToInt64();
1378 if (sign_extended || (m.left().IsChangeUint32ToUint64() &&
1379 m.right().IsChangeUint32ToUint64())) {
1380 node->ReplaceInput(0, NodeProperties::GetValueInput(m.left().node(), 0));
1381 node->ReplaceInput(1, NodeProperties::GetValueInput(m.right().node(), 0));
1382 NodeProperties::ChangeOp(node,
1383 Map64To32Comparison(node->op(), sign_extended));
1384 return Changed(node).FollowedBy(Reduce(node));
1385 }
1386
1387 // (x >>> K) < (y >>> K) => x < y if only zeros shifted out
1388 // This is useful for Smi untagging, which results in such a shift.
1389 if (m.left().op() == machine()->Word64SarShiftOutZeros() &&
1390 m.right().op() == machine()->Word64SarShiftOutZeros()) {
1391 Int64BinopMatcher mleft(m.left().node());
1392 Int64BinopMatcher mright(m.right().node());
1393 if (mleft.right().HasResolvedValue() &&
1394 mright.right().Is(mleft.right().ResolvedValue())) {
1395 node->ReplaceInput(0, mleft.left().node());
1396 node->ReplaceInput(1, mright.left().node());
1397 return Changed(node);
1398 }
1399 }
1400
1401 return NoChange();
1402 }
1403
ReduceWord32Shifts(Node * node)1404 Reduction MachineOperatorReducer::ReduceWord32Shifts(Node* node) {
1405 DCHECK((node->opcode() == IrOpcode::kWord32Shl) ||
1406 (node->opcode() == IrOpcode::kWord32Shr) ||
1407 (node->opcode() == IrOpcode::kWord32Sar));
1408 if (machine()->Word32ShiftIsSafe()) {
1409 // Remove the explicit 'and' with 0x1F if the shift provided by the machine
1410 // instruction matches that required by JavaScript.
1411 Int32BinopMatcher m(node);
1412 if (m.right().IsWord32And()) {
1413 Int32BinopMatcher mright(m.right().node());
1414 if (mright.right().Is(0x1F)) {
1415 node->ReplaceInput(1, mright.left().node());
1416 return Changed(node);
1417 }
1418 }
1419 }
1420 return NoChange();
1421 }
1422
ReduceWord32Shl(Node * node)1423 Reduction MachineOperatorReducer::ReduceWord32Shl(Node* node) {
1424 DCHECK_EQ(IrOpcode::kWord32Shl, node->opcode());
1425 Int32BinopMatcher m(node);
1426 if (m.right().Is(0)) return Replace(m.left().node()); // x << 0 => x
1427 if (m.IsFoldable()) { // K << K => K (K stands for arbitrary constants)
1428 return ReplaceInt32(base::ShlWithWraparound(m.left().ResolvedValue(),
1429 m.right().ResolvedValue()));
1430 }
1431 if (m.right().IsInRange(1, 31)) {
1432 if (m.left().IsWord32Sar() || m.left().IsWord32Shr()) {
1433 Int32BinopMatcher mleft(m.left().node());
1434
1435 // If x >> K only shifted out zeros:
1436 // (x >> K) << L => x if K == L
1437 // (x >> K) << L => x >> (K-L) if K > L
1438 // (x >> K) << L => x << (L-K) if K < L
1439 // Since this is used for Smi untagging, we currently only need it for
1440 // signed shifts.
1441 if (mleft.op() == machine()->Word32SarShiftOutZeros() &&
1442 mleft.right().IsInRange(1, 31)) {
1443 Node* x = mleft.left().node();
1444 int k = mleft.right().ResolvedValue();
1445 int l = m.right().ResolvedValue();
1446 if (k == l) {
1447 return Replace(x);
1448 } else if (k > l) {
1449 node->ReplaceInput(0, x);
1450 node->ReplaceInput(1, Uint32Constant(k - l));
1451 NodeProperties::ChangeOp(node, machine()->Word32Sar());
1452 return Changed(node).FollowedBy(ReduceWord32Sar(node));
1453 } else {
1454 DCHECK(k < l);
1455 node->ReplaceInput(0, x);
1456 node->ReplaceInput(1, Uint32Constant(l - k));
1457 return Changed(node);
1458 }
1459 }
1460
1461 // (x >>> K) << K => x & ~(2^K - 1)
1462 // (x >> K) << K => x & ~(2^K - 1)
1463 if (mleft.right().Is(m.right().ResolvedValue())) {
1464 node->ReplaceInput(0, mleft.left().node());
1465 node->ReplaceInput(1,
1466 Uint32Constant(std::numeric_limits<uint32_t>::max()
1467 << m.right().ResolvedValue()));
1468 NodeProperties::ChangeOp(node, machine()->Word32And());
1469 return Changed(node).FollowedBy(ReduceWord32And(node));
1470 }
1471 }
1472 }
1473 return ReduceWord32Shifts(node);
1474 }
1475
ReduceWord64Shl(Node * node)1476 Reduction MachineOperatorReducer::ReduceWord64Shl(Node* node) {
1477 DCHECK_EQ(IrOpcode::kWord64Shl, node->opcode());
1478 Int64BinopMatcher m(node);
1479 if (m.right().Is(0)) return Replace(m.left().node()); // x << 0 => x
1480 if (m.IsFoldable()) { // K << K => K (K stands for arbitrary constants)
1481 return ReplaceInt64(base::ShlWithWraparound(m.left().ResolvedValue(),
1482 m.right().ResolvedValue()));
1483 }
1484 if (m.right().IsInRange(1, 63) &&
1485 (m.left().IsWord64Sar() || m.left().IsWord64Shr())) {
1486 Int64BinopMatcher mleft(m.left().node());
1487
1488 // If x >> K only shifted out zeros:
1489 // (x >> K) << L => x if K == L
1490 // (x >> K) << L => x >> (K-L) if K > L
1491 // (x >> K) << L => x << (L-K) if K < L
1492 // Since this is used for Smi untagging, we currently only need it for
1493 // signed shifts.
1494 if (mleft.op() == machine()->Word64SarShiftOutZeros() &&
1495 mleft.right().IsInRange(1, 63)) {
1496 Node* x = mleft.left().node();
1497 int64_t k = mleft.right().ResolvedValue();
1498 int64_t l = m.right().ResolvedValue();
1499 if (k == l) {
1500 return Replace(x);
1501 } else if (k > l) {
1502 node->ReplaceInput(0, x);
1503 node->ReplaceInput(1, Uint64Constant(k - l));
1504 NodeProperties::ChangeOp(node, machine()->Word64Sar());
1505 return Changed(node).FollowedBy(ReduceWord64Sar(node));
1506 } else {
1507 DCHECK(k < l);
1508 node->ReplaceInput(0, x);
1509 node->ReplaceInput(1, Uint64Constant(l - k));
1510 return Changed(node);
1511 }
1512 }
1513
1514 // (x >>> K) << K => x & ~(2^K - 1)
1515 // (x >> K) << K => x & ~(2^K - 1)
1516 if (mleft.right().Is(m.right().ResolvedValue())) {
1517 node->ReplaceInput(0, mleft.left().node());
1518 node->ReplaceInput(1, Uint64Constant(std::numeric_limits<uint64_t>::max()
1519 << m.right().ResolvedValue()));
1520 NodeProperties::ChangeOp(node, machine()->Word64And());
1521 return Changed(node).FollowedBy(ReduceWord64And(node));
1522 }
1523 }
1524 return NoChange();
1525 }
1526
ReduceWord32Shr(Node * node)1527 Reduction MachineOperatorReducer::ReduceWord32Shr(Node* node) {
1528 Uint32BinopMatcher m(node);
1529 if (m.right().Is(0)) return Replace(m.left().node()); // x >>> 0 => x
1530 if (m.IsFoldable()) { // K >>> K => K (K stands for arbitrary constants)
1531 return ReplaceInt32(m.left().ResolvedValue() >>
1532 (m.right().ResolvedValue() & 31));
1533 }
1534 if (m.left().IsWord32And() && m.right().HasResolvedValue()) {
1535 Uint32BinopMatcher mleft(m.left().node());
1536 if (mleft.right().HasResolvedValue()) {
1537 uint32_t shift = m.right().ResolvedValue() & 31;
1538 uint32_t mask = mleft.right().ResolvedValue();
1539 if ((mask >> shift) == 0) {
1540 // (m >>> s) == 0 implies ((x & m) >>> s) == 0
1541 return ReplaceInt32(0);
1542 }
1543 }
1544 }
1545 return ReduceWord32Shifts(node);
1546 }
1547
ReduceWord64Shr(Node * node)1548 Reduction MachineOperatorReducer::ReduceWord64Shr(Node* node) {
1549 DCHECK_EQ(IrOpcode::kWord64Shr, node->opcode());
1550 Uint64BinopMatcher m(node);
1551 if (m.right().Is(0)) return Replace(m.left().node()); // x >>> 0 => x
1552 if (m.IsFoldable()) { // K >> K => K (K stands for arbitrary constants)
1553 return ReplaceInt64(m.left().ResolvedValue() >>
1554 (m.right().ResolvedValue() & 63));
1555 }
1556 return NoChange();
1557 }
1558
ReduceWord32Sar(Node * node)1559 Reduction MachineOperatorReducer::ReduceWord32Sar(Node* node) {
1560 Int32BinopMatcher m(node);
1561 if (m.right().Is(0)) return Replace(m.left().node()); // x >> 0 => x
1562 if (m.IsFoldable()) { // K >> K => K (K stands for arbitrary constants)
1563 return ReplaceInt32(m.left().ResolvedValue() >>
1564 (m.right().ResolvedValue() & 31));
1565 }
1566 if (m.left().IsWord32Shl()) {
1567 Int32BinopMatcher mleft(m.left().node());
1568 if (mleft.left().IsComparison()) {
1569 if (m.right().Is(31) && mleft.right().Is(31)) {
1570 // Comparison << 31 >> 31 => 0 - Comparison
1571 node->ReplaceInput(0, Int32Constant(0));
1572 node->ReplaceInput(1, mleft.left().node());
1573 NodeProperties::ChangeOp(node, machine()->Int32Sub());
1574 return Changed(node).FollowedBy(ReduceInt32Sub(node));
1575 }
1576 } else if (mleft.left().IsLoad()) {
1577 LoadRepresentation const rep =
1578 LoadRepresentationOf(mleft.left().node()->op());
1579 if (m.right().Is(24) && mleft.right().Is(24) &&
1580 rep == MachineType::Int8()) {
1581 // Load[kMachInt8] << 24 >> 24 => Load[kMachInt8]
1582 return Replace(mleft.left().node());
1583 }
1584 if (m.right().Is(16) && mleft.right().Is(16) &&
1585 rep == MachineType::Int16()) {
1586 // Load[kMachInt16] << 16 >> 16 => Load[kMachInt8]
1587 return Replace(mleft.left().node());
1588 }
1589 }
1590 }
1591 return ReduceWord32Shifts(node);
1592 }
1593
ReduceWord64Sar(Node * node)1594 Reduction MachineOperatorReducer::ReduceWord64Sar(Node* node) {
1595 Int64BinopMatcher m(node);
1596 if (m.right().Is(0)) return Replace(m.left().node()); // x >> 0 => x
1597 if (m.IsFoldable()) {
1598 return ReplaceInt64(m.left().ResolvedValue() >>
1599 (m.right().ResolvedValue() & 63));
1600 }
1601 return NoChange();
1602 }
1603
1604 template <typename WordNAdapter>
ReduceWordNAnd(Node * node)1605 Reduction MachineOperatorReducer::ReduceWordNAnd(Node* node) {
1606 using A = WordNAdapter;
1607 A a(this);
1608
1609 typename A::IntNBinopMatcher m(node);
1610 if (m.right().Is(0)) return Replace(m.right().node()); // x & 0 => 0
1611 if (m.right().Is(-1)) return Replace(m.left().node()); // x & -1 => x
1612 if (m.left().IsComparison() && m.right().Is(1)) { // CMP & 1 => CMP
1613 return Replace(m.left().node());
1614 }
1615 if (m.IsFoldable()) { // K & K => K (K stands for arbitrary constants)
1616 return a.ReplaceIntN(m.left().ResolvedValue() & m.right().ResolvedValue());
1617 }
1618 if (m.LeftEqualsRight()) return Replace(m.left().node()); // x & x => x
1619 if (A::IsWordNAnd(m.left()) && m.right().HasResolvedValue()) {
1620 typename A::IntNBinopMatcher mleft(m.left().node());
1621 if (mleft.right().HasResolvedValue()) { // (x & K) & K => x & K
1622 node->ReplaceInput(0, mleft.left().node());
1623 node->ReplaceInput(1, a.IntNConstant(m.right().ResolvedValue() &
1624 mleft.right().ResolvedValue()));
1625 return Changed(node).FollowedBy(a.ReduceWordNAnd(node));
1626 }
1627 }
1628 if (m.right().IsNegativePowerOf2()) {
1629 typename A::intN_t const mask = m.right().ResolvedValue();
1630 typename A::intN_t const neg_mask = base::NegateWithWraparound(mask);
1631 if (A::IsWordNShl(m.left())) {
1632 typename A::UintNBinopMatcher mleft(m.left().node());
1633 if (mleft.right().HasResolvedValue() &&
1634 (mleft.right().ResolvedValue() & (A::WORD_SIZE - 1)) >=
1635 base::bits::CountTrailingZeros(mask)) {
1636 // (x << L) & (-1 << K) => x << L iff L >= K
1637 return Replace(mleft.node());
1638 }
1639 } else if (A::IsIntNAdd(m.left())) {
1640 typename A::IntNBinopMatcher mleft(m.left().node());
1641 if (mleft.right().HasResolvedValue() &&
1642 (mleft.right().ResolvedValue() & mask) ==
1643 mleft.right().ResolvedValue()) {
1644 // (x + (K << L)) & (-1 << L) => (x & (-1 << L)) + (K << L)
1645 node->ReplaceInput(0,
1646 a.WordNAnd(mleft.left().node(), m.right().node()));
1647 node->ReplaceInput(1, mleft.right().node());
1648 NodeProperties::ChangeOp(node, a.IntNAdd(machine()));
1649 return Changed(node).FollowedBy(a.ReduceIntNAdd(node));
1650 }
1651 if (A::IsIntNMul(mleft.left())) {
1652 typename A::IntNBinopMatcher mleftleft(mleft.left().node());
1653 if (mleftleft.right().IsMultipleOf(neg_mask)) {
1654 // (y * (K << L) + x) & (-1 << L) => (x & (-1 << L)) + y * (K << L)
1655 node->ReplaceInput(
1656 0, a.WordNAnd(mleft.right().node(), m.right().node()));
1657 node->ReplaceInput(1, mleftleft.node());
1658 NodeProperties::ChangeOp(node, a.IntNAdd(machine()));
1659 return Changed(node).FollowedBy(a.ReduceIntNAdd(node));
1660 }
1661 }
1662 if (A::IsIntNMul(mleft.right())) {
1663 typename A::IntNBinopMatcher mleftright(mleft.right().node());
1664 if (mleftright.right().IsMultipleOf(neg_mask)) {
1665 // (x + y * (K << L)) & (-1 << L) => (x & (-1 << L)) + y * (K << L)
1666 node->ReplaceInput(0,
1667 a.WordNAnd(mleft.left().node(), m.right().node()));
1668 node->ReplaceInput(1, mleftright.node());
1669 NodeProperties::ChangeOp(node, a.IntNAdd(machine()));
1670 return Changed(node).FollowedBy(a.ReduceIntNAdd(node));
1671 }
1672 }
1673 if (A::IsWordNShl(mleft.left())) {
1674 typename A::IntNBinopMatcher mleftleft(mleft.left().node());
1675 if (mleftleft.right().Is(base::bits::CountTrailingZeros(mask))) {
1676 // (y << L + x) & (-1 << L) => (x & (-1 << L)) + y << L
1677 node->ReplaceInput(
1678 0, a.WordNAnd(mleft.right().node(), m.right().node()));
1679 node->ReplaceInput(1, mleftleft.node());
1680 NodeProperties::ChangeOp(node, a.IntNAdd(machine()));
1681 return Changed(node).FollowedBy(a.ReduceIntNAdd(node));
1682 }
1683 }
1684 if (A::IsWordNShl(mleft.right())) {
1685 typename A::IntNBinopMatcher mleftright(mleft.right().node());
1686 if (mleftright.right().Is(base::bits::CountTrailingZeros(mask))) {
1687 // (x + y << L) & (-1 << L) => (x & (-1 << L)) + y << L
1688 node->ReplaceInput(0,
1689 a.WordNAnd(mleft.left().node(), m.right().node()));
1690 node->ReplaceInput(1, mleftright.node());
1691 NodeProperties::ChangeOp(node, a.IntNAdd(machine()));
1692 return Changed(node).FollowedBy(a.ReduceIntNAdd(node));
1693 }
1694 }
1695 } else if (A::IsIntNMul(m.left())) {
1696 typename A::IntNBinopMatcher mleft(m.left().node());
1697 if (mleft.right().IsMultipleOf(neg_mask)) {
1698 // (x * (K << L)) & (-1 << L) => x * (K << L)
1699 return Replace(mleft.node());
1700 }
1701 }
1702 }
1703 return NoChange();
1704 }
1705
1706 namespace {
1707
1708 // Represents an operation of the form `(source & mask) == masked_value`.
1709 struct BitfieldCheck {
1710 Node* source;
1711 uint32_t mask;
1712 uint32_t masked_value;
1713 bool truncate_from_64_bit;
1714
Detectv8::internal::compiler::__anon5915b11c0111::BitfieldCheck1715 static base::Optional<BitfieldCheck> Detect(Node* node) {
1716 // There are two patterns to check for here:
1717 // 1. Single-bit checks: `(val >> shift) & 1`, where:
1718 // - the shift may be omitted, and/or
1719 // - the result may be truncated from 64 to 32
1720 // 2. Equality checks: `(val & mask) == expected`, where:
1721 // - val may be truncated from 64 to 32 before masking (see
1722 // ReduceWord32EqualForConstantRhs)
1723 if (node->opcode() == IrOpcode::kWord32Equal) {
1724 Uint32BinopMatcher eq(node);
1725 if (eq.left().IsWord32And()) {
1726 Uint32BinopMatcher mand(eq.left().node());
1727 if (mand.right().HasResolvedValue() && eq.right().HasResolvedValue()) {
1728 BitfieldCheck result{mand.left().node(), mand.right().ResolvedValue(),
1729 eq.right().ResolvedValue(), false};
1730 if (mand.left().IsTruncateInt64ToInt32()) {
1731 result.truncate_from_64_bit = true;
1732 result.source =
1733 NodeProperties::GetValueInput(mand.left().node(), 0);
1734 }
1735 return result;
1736 }
1737 }
1738 } else {
1739 if (node->opcode() == IrOpcode::kTruncateInt64ToInt32) {
1740 return TryDetectShiftAndMaskOneBit<Word64Adapter>(
1741 NodeProperties::GetValueInput(node, 0));
1742 } else {
1743 return TryDetectShiftAndMaskOneBit<Word32Adapter>(node);
1744 }
1745 }
1746 return {};
1747 }
1748
TryCombinev8::internal::compiler::__anon5915b11c0111::BitfieldCheck1749 base::Optional<BitfieldCheck> TryCombine(const BitfieldCheck& other) {
1750 if (source != other.source ||
1751 truncate_from_64_bit != other.truncate_from_64_bit)
1752 return {};
1753 uint32_t overlapping_bits = mask & other.mask;
1754 // It would be kind of strange to have any overlapping bits, but they can be
1755 // allowed as long as they don't require opposite values in the same
1756 // positions.
1757 if ((masked_value & overlapping_bits) !=
1758 (other.masked_value & overlapping_bits))
1759 return {};
1760 return BitfieldCheck{source, mask | other.mask,
1761 masked_value | other.masked_value,
1762 truncate_from_64_bit};
1763 }
1764
1765 private:
1766 template <typename WordNAdapter>
TryDetectShiftAndMaskOneBitv8::internal::compiler::__anon5915b11c0111::BitfieldCheck1767 static base::Optional<BitfieldCheck> TryDetectShiftAndMaskOneBit(Node* node) {
1768 // Look for the pattern `(val >> shift) & 1`. The shift may be omitted.
1769 if (WordNAdapter::IsWordNAnd(NodeMatcher(node))) {
1770 typename WordNAdapter::IntNBinopMatcher mand(node);
1771 if (mand.right().HasResolvedValue() &&
1772 mand.right().ResolvedValue() == 1) {
1773 if (WordNAdapter::IsWordNShr(mand.left()) ||
1774 WordNAdapter::IsWordNSar(mand.left())) {
1775 typename WordNAdapter::UintNBinopMatcher shift(mand.left().node());
1776 if (shift.right().HasResolvedValue() &&
1777 shift.right().ResolvedValue() < 32u) {
1778 uint32_t mask = 1 << shift.right().ResolvedValue();
1779 return BitfieldCheck{shift.left().node(), mask, mask,
1780 WordNAdapter::WORD_SIZE == 64};
1781 }
1782 }
1783 return BitfieldCheck{mand.left().node(), 1, 1,
1784 WordNAdapter::WORD_SIZE == 64};
1785 }
1786 }
1787 return {};
1788 }
1789 };
1790
1791 } // namespace
1792
ReduceWord32And(Node * node)1793 Reduction MachineOperatorReducer::ReduceWord32And(Node* node) {
1794 DCHECK_EQ(IrOpcode::kWord32And, node->opcode());
1795 Reduction reduction = ReduceWordNAnd<Word32Adapter>(node);
1796 if (reduction.Changed()) {
1797 return reduction;
1798 }
1799
1800 // Attempt to detect multiple bitfield checks from the same bitfield struct
1801 // and fold them into a single check.
1802 Int32BinopMatcher m(node);
1803 if (auto right_bitfield = BitfieldCheck::Detect(m.right().node())) {
1804 if (auto left_bitfield = BitfieldCheck::Detect(m.left().node())) {
1805 if (auto combined_bitfield = left_bitfield->TryCombine(*right_bitfield)) {
1806 Node* source = combined_bitfield->source;
1807 if (combined_bitfield->truncate_from_64_bit) {
1808 source = TruncateInt64ToInt32(source);
1809 }
1810 node->ReplaceInput(0, Word32And(source, combined_bitfield->mask));
1811 node->ReplaceInput(1, Int32Constant(combined_bitfield->masked_value));
1812 NodeProperties::ChangeOp(node, machine()->Word32Equal());
1813 return Changed(node).FollowedBy(ReduceWord32Equal(node));
1814 }
1815 }
1816 }
1817
1818 return NoChange();
1819 }
1820
ReduceWord64And(Node * node)1821 Reduction MachineOperatorReducer::ReduceWord64And(Node* node) {
1822 DCHECK_EQ(IrOpcode::kWord64And, node->opcode());
1823 return ReduceWordNAnd<Word64Adapter>(node);
1824 }
1825
TryMatchWord32Ror(Node * node)1826 Reduction MachineOperatorReducer::TryMatchWord32Ror(Node* node) {
1827 DCHECK(IrOpcode::kWord32Or == node->opcode() ||
1828 IrOpcode::kWord32Xor == node->opcode());
1829 Int32BinopMatcher m(node);
1830 Node* shl = nullptr;
1831 Node* shr = nullptr;
1832 // Recognize rotation, we are matching:
1833 // * x << y | x >>> (32 - y) => x ror (32 - y), i.e x rol y
1834 // * x << (32 - y) | x >>> y => x ror y
1835 // * x << y ^ x >>> (32 - y) => x ror (32 - y), i.e. x rol y
1836 // * x << (32 - y) ^ x >>> y => x ror y
1837 // as well as their commuted form.
1838 if (m.left().IsWord32Shl() && m.right().IsWord32Shr()) {
1839 shl = m.left().node();
1840 shr = m.right().node();
1841 } else if (m.left().IsWord32Shr() && m.right().IsWord32Shl()) {
1842 shl = m.right().node();
1843 shr = m.left().node();
1844 } else {
1845 return NoChange();
1846 }
1847
1848 Int32BinopMatcher mshl(shl);
1849 Int32BinopMatcher mshr(shr);
1850 if (mshl.left().node() != mshr.left().node()) return NoChange();
1851
1852 if (mshl.right().HasResolvedValue() && mshr.right().HasResolvedValue()) {
1853 // Case where y is a constant.
1854 if (mshl.right().ResolvedValue() + mshr.right().ResolvedValue() != 32)
1855 return NoChange();
1856 } else {
1857 Node* sub = nullptr;
1858 Node* y = nullptr;
1859 if (mshl.right().IsInt32Sub()) {
1860 sub = mshl.right().node();
1861 y = mshr.right().node();
1862 } else if (mshr.right().IsInt32Sub()) {
1863 sub = mshr.right().node();
1864 y = mshl.right().node();
1865 } else {
1866 return NoChange();
1867 }
1868
1869 Int32BinopMatcher msub(sub);
1870 if (!msub.left().Is(32) || msub.right().node() != y) return NoChange();
1871 }
1872
1873 node->ReplaceInput(0, mshl.left().node());
1874 node->ReplaceInput(1, mshr.right().node());
1875 NodeProperties::ChangeOp(node, machine()->Word32Ror());
1876 return Changed(node);
1877 }
1878
1879 template <typename WordNAdapter>
ReduceWordNOr(Node * node)1880 Reduction MachineOperatorReducer::ReduceWordNOr(Node* node) {
1881 using A = WordNAdapter;
1882 A a(this);
1883
1884 typename A::IntNBinopMatcher m(node);
1885 if (m.right().Is(0)) return Replace(m.left().node()); // x | 0 => x
1886 if (m.right().Is(-1)) return Replace(m.right().node()); // x | -1 => -1
1887 if (m.IsFoldable()) { // K | K => K (K stands for arbitrary constants)
1888 return a.ReplaceIntN(m.left().ResolvedValue() | m.right().ResolvedValue());
1889 }
1890 if (m.LeftEqualsRight()) return Replace(m.left().node()); // x | x => x
1891
1892 // (x & K1) | K2 => x | K2 if K2 has ones for every zero bit in K1.
1893 // This case can be constructed by UpdateWord and UpdateWord32 in CSA.
1894 if (m.right().HasResolvedValue()) {
1895 if (A::IsWordNAnd(m.left())) {
1896 typename A::IntNBinopMatcher mand(m.left().node());
1897 if (mand.right().HasResolvedValue()) {
1898 if ((m.right().ResolvedValue() | mand.right().ResolvedValue()) == -1) {
1899 node->ReplaceInput(0, mand.left().node());
1900 return Changed(node);
1901 }
1902 }
1903 }
1904 }
1905
1906 return a.TryMatchWordNRor(node);
1907 }
1908
ReduceWord32Or(Node * node)1909 Reduction MachineOperatorReducer::ReduceWord32Or(Node* node) {
1910 DCHECK_EQ(IrOpcode::kWord32Or, node->opcode());
1911 return ReduceWordNOr<Word32Adapter>(node);
1912 }
1913
ReduceWord64Or(Node * node)1914 Reduction MachineOperatorReducer::ReduceWord64Or(Node* node) {
1915 DCHECK_EQ(IrOpcode::kWord64Or, node->opcode());
1916 return ReduceWordNOr<Word64Adapter>(node);
1917 }
1918
1919 template <typename WordNAdapter>
ReduceWordNXor(Node * node)1920 Reduction MachineOperatorReducer::ReduceWordNXor(Node* node) {
1921 using A = WordNAdapter;
1922 A a(this);
1923
1924 typename A::IntNBinopMatcher m(node);
1925 if (m.right().Is(0)) return Replace(m.left().node()); // x ^ 0 => x
1926 if (m.IsFoldable()) { // K ^ K => K (K stands for arbitrary constants)
1927 return a.ReplaceIntN(m.left().ResolvedValue() ^ m.right().ResolvedValue());
1928 }
1929 if (m.LeftEqualsRight()) return ReplaceInt32(0); // x ^ x => 0
1930 if (A::IsWordNXor(m.left()) && m.right().Is(-1)) {
1931 typename A::IntNBinopMatcher mleft(m.left().node());
1932 if (mleft.right().Is(-1)) { // (x ^ -1) ^ -1 => x
1933 return Replace(mleft.left().node());
1934 }
1935 }
1936
1937 return a.TryMatchWordNRor(node);
1938 }
1939
ReduceWord32Xor(Node * node)1940 Reduction MachineOperatorReducer::ReduceWord32Xor(Node* node) {
1941 DCHECK_EQ(IrOpcode::kWord32Xor, node->opcode());
1942 return ReduceWordNXor<Word32Adapter>(node);
1943 }
1944
ReduceWord64Xor(Node * node)1945 Reduction MachineOperatorReducer::ReduceWord64Xor(Node* node) {
1946 DCHECK_EQ(IrOpcode::kWord64Xor, node->opcode());
1947 return ReduceWordNXor<Word64Adapter>(node);
1948 }
1949
ReduceWord32Equal(Node * node)1950 Reduction MachineOperatorReducer::ReduceWord32Equal(Node* node) {
1951 Int32BinopMatcher m(node);
1952 if (m.IsFoldable()) { // K == K => K (K stands for arbitrary constants)
1953 return ReplaceBool(m.left().ResolvedValue() == m.right().ResolvedValue());
1954 }
1955 if (m.left().IsInt32Sub() && m.right().Is(0)) { // x - y == 0 => x == y
1956 Int32BinopMatcher msub(m.left().node());
1957 node->ReplaceInput(0, msub.left().node());
1958 node->ReplaceInput(1, msub.right().node());
1959 return Changed(node);
1960 }
1961 // TODO(turbofan): fold HeapConstant, ExternalReference, pointer compares
1962 if (m.LeftEqualsRight()) return ReplaceBool(true); // x == x => true
1963 if (m.right().HasResolvedValue()) {
1964 base::Optional<std::pair<Node*, uint32_t>> replacements;
1965 if (m.left().IsTruncateInt64ToInt32()) {
1966 replacements = ReduceWord32EqualForConstantRhs<Word64Adapter>(
1967 NodeProperties::GetValueInput(m.left().node(), 0),
1968 static_cast<uint32_t>(m.right().ResolvedValue()));
1969 } else {
1970 replacements = ReduceWord32EqualForConstantRhs<Word32Adapter>(
1971 m.left().node(), static_cast<uint32_t>(m.right().ResolvedValue()));
1972 }
1973 if (replacements) {
1974 node->ReplaceInput(0, replacements->first);
1975 node->ReplaceInput(1, Uint32Constant(replacements->second));
1976 return Changed(node);
1977 }
1978 }
1979
1980 return NoChange();
1981 }
1982
ReduceFloat64InsertLowWord32(Node * node)1983 Reduction MachineOperatorReducer::ReduceFloat64InsertLowWord32(Node* node) {
1984 DCHECK_EQ(IrOpcode::kFloat64InsertLowWord32, node->opcode());
1985 Float64Matcher mlhs(node->InputAt(0));
1986 Uint32Matcher mrhs(node->InputAt(1));
1987 if (mlhs.HasResolvedValue() && mrhs.HasResolvedValue()) {
1988 return ReplaceFloat64(
1989 bit_cast<double>((bit_cast<uint64_t>(mlhs.ResolvedValue()) &
1990 uint64_t{0xFFFFFFFF00000000}) |
1991 mrhs.ResolvedValue()));
1992 }
1993 return NoChange();
1994 }
1995
ReduceFloat64InsertHighWord32(Node * node)1996 Reduction MachineOperatorReducer::ReduceFloat64InsertHighWord32(Node* node) {
1997 DCHECK_EQ(IrOpcode::kFloat64InsertHighWord32, node->opcode());
1998 Float64Matcher mlhs(node->InputAt(0));
1999 Uint32Matcher mrhs(node->InputAt(1));
2000 if (mlhs.HasResolvedValue() && mrhs.HasResolvedValue()) {
2001 return ReplaceFloat64(bit_cast<double>(
2002 (bit_cast<uint64_t>(mlhs.ResolvedValue()) & uint64_t{0xFFFFFFFF}) |
2003 (static_cast<uint64_t>(mrhs.ResolvedValue()) << 32)));
2004 }
2005 return NoChange();
2006 }
2007
2008 namespace {
2009
IsFloat64RepresentableAsFloat32(const Float64Matcher & m)2010 bool IsFloat64RepresentableAsFloat32(const Float64Matcher& m) {
2011 if (m.HasResolvedValue()) {
2012 double v = m.ResolvedValue();
2013 return DoubleToFloat32(v) == v;
2014 }
2015 return false;
2016 }
2017
2018 } // namespace
2019
2020
ReduceFloat64Compare(Node * node)2021 Reduction MachineOperatorReducer::ReduceFloat64Compare(Node* node) {
2022 DCHECK(IrOpcode::kFloat64Equal == node->opcode() ||
2023 IrOpcode::kFloat64LessThan == node->opcode() ||
2024 IrOpcode::kFloat64LessThanOrEqual == node->opcode());
2025 Float64BinopMatcher m(node);
2026 if (m.IsFoldable()) {
2027 switch (node->opcode()) {
2028 case IrOpcode::kFloat64Equal:
2029 return ReplaceBool(m.left().ResolvedValue() ==
2030 m.right().ResolvedValue());
2031 case IrOpcode::kFloat64LessThan:
2032 return ReplaceBool(m.left().ResolvedValue() <
2033 m.right().ResolvedValue());
2034 case IrOpcode::kFloat64LessThanOrEqual:
2035 return ReplaceBool(m.left().ResolvedValue() <=
2036 m.right().ResolvedValue());
2037 default:
2038 UNREACHABLE();
2039 }
2040 } else if ((m.left().IsChangeFloat32ToFloat64() &&
2041 m.right().IsChangeFloat32ToFloat64()) ||
2042 (m.left().IsChangeFloat32ToFloat64() &&
2043 IsFloat64RepresentableAsFloat32(m.right())) ||
2044 (IsFloat64RepresentableAsFloat32(m.left()) &&
2045 m.right().IsChangeFloat32ToFloat64())) {
2046 // As all Float32 values have an exact representation in Float64, comparing
2047 // two Float64 values both converted from Float32 is equivalent to comparing
2048 // the original Float32s, so we can ignore the conversions. We can also
2049 // reduce comparisons of converted Float64 values against constants that
2050 // can be represented exactly as Float32.
2051 switch (node->opcode()) {
2052 case IrOpcode::kFloat64Equal:
2053 NodeProperties::ChangeOp(node, machine()->Float32Equal());
2054 break;
2055 case IrOpcode::kFloat64LessThan:
2056 NodeProperties::ChangeOp(node, machine()->Float32LessThan());
2057 break;
2058 case IrOpcode::kFloat64LessThanOrEqual:
2059 NodeProperties::ChangeOp(node, machine()->Float32LessThanOrEqual());
2060 break;
2061 default:
2062 UNREACHABLE();
2063 }
2064 node->ReplaceInput(
2065 0, m.left().HasResolvedValue()
2066 ? Float32Constant(static_cast<float>(m.left().ResolvedValue()))
2067 : m.left().InputAt(0));
2068 node->ReplaceInput(
2069 1, m.right().HasResolvedValue()
2070 ? Float32Constant(static_cast<float>(m.right().ResolvedValue()))
2071 : m.right().InputAt(0));
2072 return Changed(node);
2073 }
2074 return NoChange();
2075 }
2076
ReduceFloat64RoundDown(Node * node)2077 Reduction MachineOperatorReducer::ReduceFloat64RoundDown(Node* node) {
2078 DCHECK_EQ(IrOpcode::kFloat64RoundDown, node->opcode());
2079 Float64Matcher m(node->InputAt(0));
2080 if (m.HasResolvedValue()) {
2081 return ReplaceFloat64(std::floor(m.ResolvedValue()));
2082 }
2083 return NoChange();
2084 }
2085
ReduceConditional(Node * node)2086 Reduction MachineOperatorReducer::ReduceConditional(Node* node) {
2087 DCHECK(node->opcode() == IrOpcode::kBranch ||
2088 node->opcode() == IrOpcode::kDeoptimizeIf ||
2089 node->opcode() == IrOpcode::kDeoptimizeUnless ||
2090 node->opcode() == IrOpcode::kTrapIf ||
2091 node->opcode() == IrOpcode::kTrapUnless);
2092 // This reducer only applies operator reductions to the branch condition.
2093 // Reductions involving control flow happen elsewhere. Non-zero inputs are
2094 // considered true in all conditional ops.
2095 NodeMatcher condition(NodeProperties::GetValueInput(node, 0));
2096 if (condition.IsTruncateInt64ToInt32()) {
2097 if (auto replacement =
2098 ReduceConditionalN<Word64Adapter>(condition.node())) {
2099 NodeProperties::ReplaceValueInput(node, *replacement, 0);
2100 return Changed(node);
2101 }
2102 } else if (auto replacement = ReduceConditionalN<Word32Adapter>(node)) {
2103 NodeProperties::ReplaceValueInput(node, *replacement, 0);
2104 return Changed(node);
2105 }
2106 return NoChange();
2107 }
2108
2109 template <typename WordNAdapter>
ReduceConditionalN(Node * node)2110 base::Optional<Node*> MachineOperatorReducer::ReduceConditionalN(Node* node) {
2111 NodeMatcher condition(NodeProperties::GetValueInput(node, 0));
2112 // Branch conditions are 32-bit comparisons against zero, so they are the
2113 // opposite of a 32-bit `x == 0` node. To avoid repetition, we can reuse logic
2114 // for Word32Equal: if `x == 0` can reduce to `y == 0`, then branch(x) can
2115 // reduce to branch(y).
2116 auto replacements =
2117 ReduceWord32EqualForConstantRhs<WordNAdapter>(condition.node(), 0);
2118 if (replacements && replacements->second == 0) return replacements->first;
2119 return {};
2120 }
2121
2122 template <typename WordNAdapter>
2123 base::Optional<std::pair<Node*, uint32_t>>
ReduceWord32EqualForConstantRhs(Node * lhs,uint32_t rhs)2124 MachineOperatorReducer::ReduceWord32EqualForConstantRhs(Node* lhs,
2125 uint32_t rhs) {
2126 if (WordNAdapter::IsWordNAnd(NodeMatcher(lhs))) {
2127 typename WordNAdapter::UintNBinopMatcher mand(lhs);
2128 if ((WordNAdapter::IsWordNShr(mand.left()) ||
2129 WordNAdapter::IsWordNSar(mand.left())) &&
2130 mand.right().HasResolvedValue()) {
2131 typename WordNAdapter::UintNBinopMatcher mshift(mand.left().node());
2132 // ((x >> K1) & K2) == K3 => (x & (K2 << K1)) == (K3 << K1)
2133 if (mshift.right().HasResolvedValue()) {
2134 auto shift_bits = mshift.right().ResolvedValue();
2135 auto mask = mand.right().ResolvedValue();
2136 // Make sure that we won't shift data off the end, and that all of the
2137 // data ends up in the lower 32 bits for 64-bit mode.
2138 if (shift_bits <= base::bits::CountLeadingZeros(mask) &&
2139 shift_bits <= base::bits::CountLeadingZeros(rhs) &&
2140 mask << shift_bits <= std::numeric_limits<uint32_t>::max()) {
2141 Node* new_input = mshift.left().node();
2142 uint32_t new_mask = static_cast<uint32_t>(mask << shift_bits);
2143 uint32_t new_rhs = rhs << shift_bits;
2144 if (WordNAdapter::WORD_SIZE == 64) {
2145 // We can truncate before performing the And.
2146 new_input = TruncateInt64ToInt32(new_input);
2147 }
2148 return std::make_pair(Word32And(new_input, new_mask), new_rhs);
2149 }
2150 }
2151 }
2152 }
2153 return {};
2154 }
2155
common() const2156 CommonOperatorBuilder* MachineOperatorReducer::common() const {
2157 return mcgraph()->common();
2158 }
2159
machine() const2160 MachineOperatorBuilder* MachineOperatorReducer::machine() const {
2161 return mcgraph()->machine();
2162 }
2163
graph() const2164 Graph* MachineOperatorReducer::graph() const { return mcgraph()->graph(); }
2165
2166 } // namespace compiler
2167 } // namespace internal
2168 } // namespace v8
2169