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[turbofan] Fold word32 representation changes for checked constants.

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If we know that a constant can be represented as word32, then we don't
need to insert a checked conversion, but just change the constant
appropriately.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2100063002
Cr-Commit-Position: refs/heads/master@{#37273}
This commit is contained in:
bmeurer 2016-06-27 00:43:45 -07:00 committed by Commit bot
parent 8c8a9f18fb
commit bd8a36a727
1 changed files with 23 additions and 12 deletions
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35
src/compiler/representation-change.cc
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@ -368,19 +368,30 @@ Node* RepresentationChanger::GetWord32RepresentationFor(
Node* node, MachineRepresentation output_rep, Type* output_type,
Node* use_node, UseInfo use_info) {
// Eagerly fold representation changes for constants.
// TODO(jarin) Properly fold constants in presence of type check.
if (use_info.type_check() == TypeCheckKind::kNone) {
switch (node->opcode()) {
case IrOpcode::kInt32Constant:
return node; // No change necessary.
case IrOpcode::kFloat32Constant:
return MakeTruncatedInt32Constant(OpParameter<float>(node));
case IrOpcode::kNumberConstant:
case IrOpcode::kFloat64Constant:
return MakeTruncatedInt32Constant(OpParameter<double>(node));
default:
break;
switch (node->opcode()) {
case IrOpcode::kInt32Constant:
return node; // No change necessary.
case IrOpcode::kFloat32Constant: {
float const fv = OpParameter<float>(node);
if (use_info.type_check() == TypeCheckKind::kNone ||
(use_info.type_check() == TypeCheckKind::kSigned32 &&
IsInt32Double(fv))) {
return MakeTruncatedInt32Constant(fv);
}
break;
}
case IrOpcode::kNumberConstant:
case IrOpcode::kFloat64Constant: {
double const fv = OpParameter<double>(node);
if (use_info.type_check() == TypeCheckKind::kNone ||
(use_info.type_check() == TypeCheckKind::kSigned32 &&
IsInt32Double(fv))) {
return MakeTruncatedInt32Constant(fv);
}
break;
}
default:
break;
}
// Select the correct X -> Word32 operator.