Index: src/hydrogen-uint32-analysis.cc |
diff --git a/src/hydrogen-uint32-analysis.cc b/src/hydrogen-uint32-analysis.cc |
deleted file mode 100644 |
index c6cbc9bc357988a8e46fcb460b708cc67ddb023b..0000000000000000000000000000000000000000 |
--- a/src/hydrogen-uint32-analysis.cc |
+++ /dev/null |
@@ -1,237 +0,0 @@ |
-// Copyright 2013 the V8 project authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include "src/hydrogen-uint32-analysis.h" |
- |
-namespace v8 { |
-namespace internal { |
- |
- |
-static bool IsUnsignedLoad(HLoadKeyed* instr) { |
- switch (instr->elements_kind()) { |
- case UINT8_ELEMENTS: |
- case UINT16_ELEMENTS: |
- case UINT32_ELEMENTS: |
- case UINT8_CLAMPED_ELEMENTS: |
- return true; |
- default: |
- return false; |
- } |
-} |
- |
- |
-static bool IsUint32Operation(HValue* instr) { |
- return instr->IsShr() || |
- (instr->IsLoadKeyed() && IsUnsignedLoad(HLoadKeyed::cast(instr))) || |
- (instr->IsInteger32Constant() && instr->GetInteger32Constant() >= 0); |
-} |
- |
- |
-bool HUint32AnalysisPhase::IsSafeUint32Use(HValue* val, HValue* use) { |
- // Operations that operate on bits are safe. |
- if (use->IsBitwise() || use->IsShl() || use->IsSar() || use->IsShr()) { |
- return true; |
- } else if (use->IsSimulate() || use->IsArgumentsObject()) { |
- // Deoptimization has special support for uint32. |
- return true; |
- } else if (use->IsChange()) { |
- // Conversions have special support for uint32. |
- // This DCHECK guards that the conversion in question is actually |
- // implemented. Do not extend the whitelist without adding |
- // support to LChunkBuilder::DoChange(). |
- DCHECK(HChange::cast(use)->to().IsDouble() || |
- HChange::cast(use)->to().IsSmi() || |
- HChange::cast(use)->to().IsTagged()); |
- return true; |
- } else if (use->IsStoreKeyed()) { |
- HStoreKeyed* store = HStoreKeyed::cast(use); |
- if (store->is_fixed_typed_array()) { |
- // Storing a value into an external integer array is a bit level |
- // operation. |
- if (store->value() == val) { |
- // Clamping or a conversion to double should have beed inserted. |
- DCHECK(store->elements_kind() != UINT8_CLAMPED_ELEMENTS); |
- DCHECK(store->elements_kind() != FLOAT32_ELEMENTS); |
- DCHECK(store->elements_kind() != FLOAT64_ELEMENTS); |
- return true; |
- } |
- } |
- } else if (use->IsCompareNumericAndBranch()) { |
- HCompareNumericAndBranch* c = HCompareNumericAndBranch::cast(use); |
- return IsUint32Operation(c->left()) && IsUint32Operation(c->right()); |
- } |
- |
- return false; |
-} |
- |
- |
-// Iterate over all uses and verify that they are uint32 safe: either don't |
-// distinguish between int32 and uint32 due to their bitwise nature or |
-// have special support for uint32 values. |
-// Encountered phis are optimistically treated as safe uint32 uses, |
-// marked with kUint32 flag and collected in the phis_ list. A separate |
-// pass will be performed later by UnmarkUnsafePhis to clear kUint32 from |
-// phis that are not actually uint32-safe (it requires fix point iteration). |
-bool HUint32AnalysisPhase::Uint32UsesAreSafe(HValue* uint32val) { |
- bool collect_phi_uses = false; |
- for (HUseIterator it(uint32val->uses()); !it.Done(); it.Advance()) { |
- HValue* use = it.value(); |
- |
- if (use->IsPhi()) { |
- if (!use->CheckFlag(HInstruction::kUint32)) { |
- // There is a phi use of this value from a phi that is not yet |
- // collected in phis_ array. Separate pass is required. |
- collect_phi_uses = true; |
- } |
- |
- // Optimistically treat phis as uint32 safe. |
- continue; |
- } |
- |
- if (!IsSafeUint32Use(uint32val, use)) { |
- return false; |
- } |
- } |
- |
- if (collect_phi_uses) { |
- for (HUseIterator it(uint32val->uses()); !it.Done(); it.Advance()) { |
- HValue* use = it.value(); |
- |
- // There is a phi use of this value from a phi that is not yet |
- // collected in phis_ array. Separate pass is required. |
- if (use->IsPhi() && !use->CheckFlag(HInstruction::kUint32)) { |
- use->SetFlag(HInstruction::kUint32); |
- phis_.Add(HPhi::cast(use), zone()); |
- } |
- } |
- } |
- |
- return true; |
-} |
- |
- |
-// Check if all operands to the given phi are marked with kUint32 flag. |
-bool HUint32AnalysisPhase::CheckPhiOperands(HPhi* phi) { |
- if (!phi->CheckFlag(HInstruction::kUint32)) { |
- // This phi is not uint32 safe. No need to check operands. |
- return false; |
- } |
- |
- for (int j = 0; j < phi->OperandCount(); j++) { |
- HValue* operand = phi->OperandAt(j); |
- if (!operand->CheckFlag(HInstruction::kUint32)) { |
- // Lazily mark constants that fit into uint32 range with kUint32 flag. |
- if (operand->IsInteger32Constant() && |
- operand->GetInteger32Constant() >= 0) { |
- operand->SetFlag(HInstruction::kUint32); |
- continue; |
- } |
- |
- // This phi is not safe, some operands are not uint32 values. |
- return false; |
- } |
- } |
- |
- return true; |
-} |
- |
- |
-// Remove kUint32 flag from the phi itself and its operands. If any operand |
-// was a phi marked with kUint32 place it into a worklist for |
-// transitive clearing of kUint32 flag. |
-void HUint32AnalysisPhase::UnmarkPhi(HPhi* phi, ZoneList<HPhi*>* worklist) { |
- phi->ClearFlag(HInstruction::kUint32); |
- for (int j = 0; j < phi->OperandCount(); j++) { |
- HValue* operand = phi->OperandAt(j); |
- if (operand->CheckFlag(HInstruction::kUint32)) { |
- operand->ClearFlag(HInstruction::kUint32); |
- if (operand->IsPhi()) { |
- worklist->Add(HPhi::cast(operand), zone()); |
- } |
- } |
- } |
-} |
- |
- |
-void HUint32AnalysisPhase::UnmarkUnsafePhis() { |
- // No phis were collected. Nothing to do. |
- if (phis_.length() == 0) return; |
- |
- // Worklist used to transitively clear kUint32 from phis that |
- // are used as arguments to other phis. |
- ZoneList<HPhi*> worklist(phis_.length(), zone()); |
- |
- // Phi can be used as a uint32 value if and only if |
- // all its operands are uint32 values and all its |
- // uses are uint32 safe. |
- |
- // Iterate over collected phis and unmark those that |
- // are unsafe. When unmarking phi unmark its operands |
- // and add it to the worklist if it is a phi as well. |
- // Phis that are still marked as safe are shifted down |
- // so that all safe phis form a prefix of the phis_ array. |
- int phi_count = 0; |
- for (int i = 0; i < phis_.length(); i++) { |
- HPhi* phi = phis_[i]; |
- |
- if (CheckPhiOperands(phi) && Uint32UsesAreSafe(phi)) { |
- phis_[phi_count++] = phi; |
- } else { |
- UnmarkPhi(phi, &worklist); |
- } |
- } |
- |
- // Now phis array contains only those phis that have safe |
- // non-phi uses. Start transitively clearing kUint32 flag |
- // from phi operands of discovered non-safe phis until |
- // only safe phis are left. |
- while (!worklist.is_empty()) { |
- while (!worklist.is_empty()) { |
- HPhi* phi = worklist.RemoveLast(); |
- UnmarkPhi(phi, &worklist); |
- } |
- |
- // Check if any operands to safe phis were unmarked |
- // turning a safe phi into unsafe. The same value |
- // can flow into several phis. |
- int new_phi_count = 0; |
- for (int i = 0; i < phi_count; i++) { |
- HPhi* phi = phis_[i]; |
- |
- if (CheckPhiOperands(phi)) { |
- phis_[new_phi_count++] = phi; |
- } else { |
- UnmarkPhi(phi, &worklist); |
- } |
- } |
- phi_count = new_phi_count; |
- } |
-} |
- |
- |
-void HUint32AnalysisPhase::Run() { |
- if (!graph()->has_uint32_instructions()) return; |
- |
- ZoneList<HInstruction*>* uint32_instructions = graph()->uint32_instructions(); |
- for (int i = 0; i < uint32_instructions->length(); ++i) { |
- // Analyze instruction and mark it with kUint32 if all |
- // its uses are uint32 safe. |
- HInstruction* current = uint32_instructions->at(i); |
- if (current->IsLinked() && |
- current->representation().IsInteger32() && |
- Uint32UsesAreSafe(current)) { |
- current->SetFlag(HInstruction::kUint32); |
- } |
- } |
- |
- // Some phis might have been optimistically marked with kUint32 flag. |
- // Remove this flag from those phis that are unsafe and propagate |
- // this information transitively potentially clearing kUint32 flag |
- // from some non-phi operations that are used as operands to unsafe phis. |
- UnmarkUnsafePhis(); |
-} |
- |
- |
-} // namespace internal |
-} // namespace v8 |