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Unified Diff: src/hydrogen-uint32-analysis.cc

Issue 1405363003: Move Hydrogen and Lithium to src/crankshaft/ (Closed) Base URL: https://chromium.googlesource.com/v8/v8.git@master
Patch Set: rebased Created 5 years, 2 months ago
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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
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