v8/src/hydrogen-representation-changes.cc
vegorov@chromium.org 8f170a66e7 Improve positions tracking inside the HGraphBuilder.
Instead of tracking simple absolute offset from the start of the script like other places do, track a pair of (inlining id, offset from the start of inlined function).

This enables us to pinpoint with inlining path an instruction came from. Previously in multi-script environments we emitted positions that made very little sense because inside a single optimized function they would point to different scripts without a way to distinguish them.

Start dumping the source of every inlined function to make possible IR viewing tools with integrated source views as there was previously no way to acquire this information from IR dumps. We also dump source position at which each inlining occured.

Tracked positions are written into hydrogen.cfg as pos:<inlining-id>_<offset>.

Flag --emit-opt-code-positions is renamed by this change into --hydrogen-track-positions to better convey it's meaning.

In addition this change assigned global unique identifier to each optimization performed inside isolate. This allows to precisely match compilation artifacts (e.g. IR and disassembly) and deoptimizations.

BUG=
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/140683011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19360 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-02-13 16:09:28 +00:00

199 lines
7.7 KiB
C++

// 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_to_smi = use_value->CheckFlag(HValue::kTruncatingToSmi);
bool is_truncating_to_int = use_value->CheckFlag(HValue::kTruncatingToInt32);
if (value->IsConstant()) {
HConstant* constant = HConstant::cast(value);
// Try to create a new copy of the constant with the new representation.
if (is_truncating_to_int && to.IsInteger32()) {
Maybe<HConstant*> res = constant->CopyToTruncatedInt32(graph()->zone());
if (res.has_value) new_value = res.value;
} else {
new_value = constant->CopyToRepresentation(to, graph()->zone());
}
}
if (new_value == NULL) {
new_value = new(graph()->zone()) HChange(
value, to, is_truncating_to_smi, is_truncating_to_int);
if (!use_value->operand_position(use_index).IsUnknown()) {
new_value->set_position(use_value->operand_position(use_index));
} else {
ASSERT(!FLAG_hydrogen_track_positions ||
!graph()->info()->IsOptimizing());
}
}
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*> int_worklist(8, zone());
ZoneList<HPhi*> smi_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);
} else if (phi->representation().IsSmi()) {
phi->SetFlag(HValue::kTruncatingToSmi);
phi->SetFlag(HValue::kTruncatingToInt32);
}
}
for (int i = 0; i < phi_list->length(); i++) {
HPhi* phi = phi_list->at(i);
HValue* value = NULL;
if (phi->representation().IsSmiOrInteger32() &&
!phi->CheckUsesForFlag(HValue::kTruncatingToInt32, &value)) {
int_worklist.Add(phi, zone());
phi->ClearFlag(HValue::kTruncatingToInt32);
if (FLAG_trace_representation) {
PrintF("#%d Phi is not truncating Int32 because of #%d %s\n",
phi->id(), value->id(), value->Mnemonic());
}
}
if (phi->representation().IsSmi() &&
!phi->CheckUsesForFlag(HValue::kTruncatingToSmi, &value)) {
smi_worklist.Add(phi, zone());
phi->ClearFlag(HValue::kTruncatingToSmi);
if (FLAG_trace_representation) {
PrintF("#%d Phi is not truncating Smi because of #%d %s\n",
phi->id(), value->id(), value->Mnemonic());
}
}
}
while (!int_worklist.is_empty()) {
HPhi* current = int_worklist.RemoveLast();
for (int i = 0; i < current->OperandCount(); ++i) {
HValue* input = current->OperandAt(i);
if (input->IsPhi() &&
input->representation().IsSmiOrInteger32() &&
input->CheckFlag(HValue::kTruncatingToInt32)) {
if (FLAG_trace_representation) {
PrintF("#%d Phi is not truncating Int32 because of #%d %s\n",
input->id(), current->id(), current->Mnemonic());
}
input->ClearFlag(HValue::kTruncatingToInt32);
int_worklist.Add(HPhi::cast(input), zone());
}
}
}
while (!smi_worklist.is_empty()) {
HPhi* current = smi_worklist.RemoveLast();
for (int i = 0; i < current->OperandCount(); ++i) {
HValue* input = current->OperandAt(i);
if (input->IsPhi() &&
input->representation().IsSmi() &&
input->CheckFlag(HValue::kTruncatingToSmi)) {
if (FLAG_trace_representation) {
PrintF("#%d Phi is not truncating Smi because of #%d %s\n",
input->id(), current->id(), current->Mnemonic());
}
input->ClearFlag(HValue::kTruncatingToSmi);
smi_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