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Turn the representation changes into a proper HPhase.

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R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/18832002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15541 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
bmeurer@chromium.org 2013-07-08 09:02:09 +00:00
parent eea586f2a1
commit 47df386841
5 changed files with 226 additions and 142 deletions
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167
src/hydrogen-representation-changes.cc Normal file
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@ -0,0 +1,167 @@
// Copyright 2013 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "hydrogen-representation-changes.h"
namespace v8 {
namespace internal {
void HRepresentationChangesPhase::InsertRepresentationChangeForUse(
HValue* value, HValue* use_value, int use_index, Representation to) {
// Insert the representation change right before its use. For phi-uses we
// insert at the end of the corresponding predecessor.
HInstruction* next = NULL;
if (use_value->IsPhi()) {
next = use_value->block()->predecessors()->at(use_index)->end();
} else {
next = HInstruction::cast(use_value);
}
// For constants we try to make the representation change at compile
// time. When a representation change is not possible without loss of
// information we treat constants like normal instructions and insert the
// change instructions for them.
HInstruction* new_value = NULL;
bool is_truncating = use_value->CheckFlag(HValue::kTruncatingToInt32);
bool allow_undefined_as_nan =
use_value->CheckFlag(HValue::kAllowUndefinedAsNaN);
if (value->IsConstant()) {
HConstant* constant = HConstant::cast(value);
// Try to create a new copy of the constant with the new representation.
new_value = (is_truncating && to.IsInteger32())
? constant->CopyToTruncatedInt32(graph()->zone())
: constant->CopyToRepresentation(to, graph()->zone());
}
if (new_value == NULL) {
new_value = new(graph()->zone()) HChange(value, to,
is_truncating,
allow_undefined_as_nan);
}
new_value->InsertBefore(next);
use_value->SetOperandAt(use_index, new_value);
}
void HRepresentationChangesPhase::InsertRepresentationChangesForValue(
HValue* value) {
Representation r = value->representation();
if (r.IsNone()) return;
if (value->HasNoUses()) return;
for (HUseIterator it(value->uses()); !it.Done(); it.Advance()) {
HValue* use_value = it.value();
int use_index = it.index();
Representation req = use_value->RequiredInputRepresentation(use_index);
if (req.IsNone() || req.Equals(r)) continue;
InsertRepresentationChangeForUse(value, use_value, use_index, req);
}
if (value->HasNoUses()) {
ASSERT(value->IsConstant());
value->DeleteAndReplaceWith(NULL);
}
// The only purpose of a HForceRepresentation is to represent the value
// after the (possible) HChange instruction. We make it disappear.
if (value->IsForceRepresentation()) {
value->DeleteAndReplaceWith(HForceRepresentation::cast(value)->value());
}
}
void HRepresentationChangesPhase::Run() {
// Compute truncation flag for phis: Initially assume that all
// int32-phis allow truncation and iteratively remove the ones that
// are used in an operation that does not allow a truncating
// conversion.
ZoneList<HPhi*> worklist(8, zone());
const ZoneList<HPhi*>* phi_list(graph()->phi_list());
for (int i = 0; i < phi_list->length(); i++) {
HPhi* phi = phi_list->at(i);
if (phi->representation().IsInteger32()) {
phi->SetFlag(HValue::kTruncatingToInt32);
}
}
for (int i = 0; i < phi_list->length(); i++) {
HPhi* phi = phi_list->at(i);
for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) {
// If a Phi is used as a non-truncating int32 or as a double,
// clear its "truncating" flag.
HValue* use = it.value();
Representation input_representation =
use->RequiredInputRepresentation(it.index());
if (!input_representation.IsInteger32() ||
!use->CheckFlag(HValue::kTruncatingToInt32)) {
if (FLAG_trace_representation) {
PrintF("#%d Phi is not truncating because of #%d %s\n",
phi->id(), it.value()->id(), it.value()->Mnemonic());
}
phi->ClearFlag(HValue::kTruncatingToInt32);
worklist.Add(phi, zone());
break;
}
}
}
while (!worklist.is_empty()) {
HPhi* current = worklist.RemoveLast();
for (int i = 0; i < current->OperandCount(); ++i) {
HValue* input = current->OperandAt(i);
if (input->IsPhi() &&
input->representation().IsInteger32() &&
input->CheckFlag(HValue::kTruncatingToInt32)) {
if (FLAG_trace_representation) {
PrintF("#%d Phi is not truncating because of #%d %s\n",
input->id(), current->id(), current->Mnemonic());
}
input->ClearFlag(HValue::kTruncatingToInt32);
worklist.Add(HPhi::cast(input), zone());
}
}
}
const ZoneList<HBasicBlock*>* blocks(graph()->blocks());
for (int i = 0; i < blocks->length(); ++i) {
// Process phi instructions first.
const HBasicBlock* block(blocks->at(i));
const ZoneList<HPhi*>* phis = block->phis();
for (int j = 0; j < phis->length(); j++) {
InsertRepresentationChangesForValue(phis->at(j));
}
// Process normal instructions.
for (HInstruction* current = block->first(); current != NULL; ) {
HInstruction* next = current->next();
InsertRepresentationChangesForValue(current);
current = next;
}
}
}
} } // namespace v8::internal

55
src/hydrogen-representation-changes.h Normal file
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@ -0,0 +1,55 @@
// Copyright 2013 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_HYDROGEN_REPRESENTATION_CHANGES_H_
#define V8_HYDROGEN_REPRESENTATION_CHANGES_H_
#include "hydrogen.h"
namespace v8 {
namespace internal {
class HRepresentationChangesPhase : public HPhase {
public:
explicit HRepresentationChangesPhase(HGraph* graph)
: HPhase("H_Representation changes", graph) { }
void Run();
private:
void InsertRepresentationChangeForUse(HValue* value,
HValue* use_value,
int use_index,
Representation to);
void InsertRepresentationChangesForValue(HValue* value);
};
} } // namespace v8::internal
#endif // V8_HYDROGEN_REPRESENTATION_CHANGES_H_

138
src/hydrogen.cc
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@ -43,6 +43,7 @@
#include "hydrogen-osr.h"
#include "hydrogen-range-analysis.h"
#include "hydrogen-redundant-phi.h"
#include "hydrogen-representation-changes.h"
#include "hydrogen-sce.h"
#include "hydrogen-uint32-analysis.h"
#include "lithium-allocator.h"
@ -2668,141 +2669,6 @@ void HGraph::PropagateMinusZeroChecks(HValue* value, BitVector* visited) {
}
void HGraph::InsertRepresentationChangeForUse(HValue* value,
HValue* use_value,
int use_index,
Representation to) {
// Insert the representation change right before its use. For phi-uses we
// insert at the end of the corresponding predecessor.
HInstruction* next = NULL;
if (use_value->IsPhi()) {
next = use_value->block()->predecessors()->at(use_index)->end();
} else {
next = HInstruction::cast(use_value);
}
// For constants we try to make the representation change at compile
// time. When a representation change is not possible without loss of
// information we treat constants like normal instructions and insert the
// change instructions for them.
HInstruction* new_value = NULL;
bool is_truncating = use_value->CheckFlag(HValue::kTruncatingToInt32);
bool allow_undefined_as_nan =
use_value->CheckFlag(HValue::kAllowUndefinedAsNaN);
if (value->IsConstant()) {
HConstant* constant = HConstant::cast(value);
// Try to create a new copy of the constant with the new representation.
new_value = (is_truncating && to.IsInteger32())
? constant->CopyToTruncatedInt32(zone())
: constant->CopyToRepresentation(to, zone());
}
if (new_value == NULL) {
new_value = new(zone()) HChange(value, to,
is_truncating, allow_undefined_as_nan);
}
new_value->InsertBefore(next);
use_value->SetOperandAt(use_index, new_value);
}
void HGraph::InsertRepresentationChangesForValue(HValue* value) {
Representation r = value->representation();
if (r.IsNone()) return;
if (value->HasNoUses()) return;
for (HUseIterator it(value->uses()); !it.Done(); it.Advance()) {
HValue* use_value = it.value();
int use_index = it.index();
Representation req = use_value->RequiredInputRepresentation(use_index);
if (req.IsNone() || req.Equals(r)) continue;
InsertRepresentationChangeForUse(value, use_value, use_index, req);
}
if (value->HasNoUses()) {
ASSERT(value->IsConstant());
value->DeleteAndReplaceWith(NULL);
}
// The only purpose of a HForceRepresentation is to represent the value
// after the (possible) HChange instruction. We make it disappear.
if (value->IsForceRepresentation()) {
value->DeleteAndReplaceWith(HForceRepresentation::cast(value)->value());
}
}
void HGraph::InsertRepresentationChanges() {
HPhase phase("H_Representation changes", this);
// Compute truncation flag for phis: Initially assume that all
// int32-phis allow truncation and iteratively remove the ones that
// are used in an operation that does not allow a truncating
// conversion.
ZoneList<HPhi*> worklist(8, zone());
for (int i = 0; i < phi_list()->length(); i++) {
HPhi* phi = phi_list()->at(i);
if (phi->representation().IsInteger32()) {
phi->SetFlag(HValue::kTruncatingToInt32);
}
}
for (int i = 0; i < phi_list()->length(); i++) {
HPhi* phi = phi_list()->at(i);
for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) {
// If a Phi is used as a non-truncating int32 or as a double,
// clear its "truncating" flag.
HValue* use = it.value();
Representation input_representation =
use->RequiredInputRepresentation(it.index());
if (!input_representation.IsInteger32() ||
!use->CheckFlag(HValue::kTruncatingToInt32)) {
if (FLAG_trace_representation) {
PrintF("#%d Phi is not truncating because of #%d %s\n",
phi->id(), it.value()->id(), it.value()->Mnemonic());
}
phi->ClearFlag(HValue::kTruncatingToInt32);
worklist.Add(phi, zone());
break;
}
}
}
while (!worklist.is_empty()) {
HPhi* current = worklist.RemoveLast();
for (int i = 0; i < current->OperandCount(); ++i) {
HValue* input = current->OperandAt(i);
if (input->IsPhi() &&
input->representation().IsInteger32() &&
input->CheckFlag(HValue::kTruncatingToInt32)) {
if (FLAG_trace_representation) {
PrintF("#%d Phi is not truncating because of #%d %s\n",
input->id(), current->id(), current->Mnemonic());
}
input->ClearFlag(HValue::kTruncatingToInt32);
worklist.Add(HPhi::cast(input), zone());
}
}
}
for (int i = 0; i < blocks_.length(); ++i) {
// Process phi instructions first.
const ZoneList<HPhi*>* phis = blocks_[i]->phis();
for (int j = 0; j < phis->length(); j++) {
InsertRepresentationChangesForValue(phis->at(j));
}
// Process normal instructions.
HInstruction* current = blocks_[i]->first();
while (current != NULL) {
HInstruction* next = current->next();
InsertRepresentationChangesForValue(current);
current = next;
}
}
}
void HGraph::RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi) {
if (!phi->CheckFlag(HValue::kAllowUndefinedAsNaN)) return;
phi->ClearFlag(HValue::kAllowUndefinedAsNaN);
@ -3334,7 +3200,7 @@ bool HGraph::Optimize(SmartArrayPointer<char>* bailout_reason) {
MergeRemovableSimulates();
MarkDeoptimizeOnUndefined();
InsertRepresentationChanges();
Run<HRepresentationChangesPhase>();
Run<HInferTypesPhase>();

6
src/hydrogen.h
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@ -293,7 +293,6 @@ class HGraph: public ZoneObject {
void FinalizeUniqueValueIds();
void InsertTypeConversions();
void MergeRemovableSimulates();
void InsertRepresentationChanges();
void MarkDeoptimizeOnUndefined();
void ComputeMinusZeroChecks();
bool ProcessArgumentsObject();
@ -452,11 +451,6 @@ class HGraph: public ZoneObject {
void InsertTypeConversions(HInstruction* instr);
void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
void InsertRepresentationChangeForUse(HValue* value,
HValue* use_value,
int use_index,
Representation to);
void InsertRepresentationChangesForValue(HValue* value);
void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
void SetupInformativeDefinitionsInBlock(HBasicBlock* block);
void SetupInformativeDefinitionsRecursively(HBasicBlock* block);

2
tools/gyp/v8.gyp
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@ -357,6 +357,8 @@
'../../src/hydrogen-range-analysis.h',
'../../src/hydrogen-redundant-phi.cc',
'../../src/hydrogen-redundant-phi.h',
'../../src/hydrogen-representation-changes.cc',
'../../src/hydrogen-representation-changes.h',
'../../src/hydrogen-sce.cc',
'../../src/hydrogen-sce.h',
'../../src/hydrogen-uint32-analysis.cc',