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[turbofan] Don't loose checked Uint32 -> Int32 conversion

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Bug: chromium:901798
Change-Id: I4b479d6431cc7cdfa53f9cdf6283d2ff86e32821
Reviewed-on: https://chromium-review.googlesource.com/c/1319760
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57285}
This commit is contained in:
Sigurd Schneider 2018-11-06 14:55:53 +01:00 committed by Commit Bot
parent 1e1ca02865
commit 201a0c67b8
3 changed files with 25 additions and 8 deletions
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14
src/compiler/representation-change.cc
View File

@ -810,19 +810,17 @@ Node* RepresentationChanger::GetWord32RepresentationFor(
MachineRepresentation::kWord32);
}
} else if (output_rep == MachineRepresentation::kWord32) {
if (use_info.truncation().IdentifiesZeroAndMinusZero()) {
if (output_type.Is(Type::Signed32OrMinusZero()) ||
output_type.Is(Type::Unsigned32OrMinusZero())) {
return node;
}
}
// Only the checked case should get here, the non-checked case is
// handled in GetRepresentationFor.
if (use_info.type_check() == TypeCheckKind::kSignedSmall ||
use_info.type_check() == TypeCheckKind::kSigned32) {
if (output_type.Is(Type::Signed32())) {
bool indentify_zeros = use_info.truncation().IdentifiesZeroAndMinusZero();
if (output_type.Is(Type::Signed32()) ||
(indentify_zeros && output_type.Is(Type::Signed32OrMinusZero()))) {
return node;
} else if (output_type.Is(Type::Unsigned32())) {
} else if (output_type.Is(Type::Unsigned32()) ||
(indentify_zeros &&
output_type.Is(Type::Unsigned32OrMinusZero()))) {
op = simplified()->CheckedUint32ToInt32(use_info.feedback());
} else {
return TypeError(node, output_rep, output_type,

5
test/cctest/compiler/test-representation-change.cc
View File

@ -615,6 +615,11 @@ TEST(SignednessInWord32) {
IrOpcode::kTruncateFloat64ToWord32,
MachineRepresentation::kFloat32, Type::Number(),
MachineRepresentation::kWord32);
CheckChange(
IrOpcode::kCheckedUint32ToInt32, MachineRepresentation::kWord32,
Type::Unsigned32(),
UseInfo::CheckedSigned32AsWord32(kIdentifyZeros, VectorSlotPair()));
}
static void TestMinusZeroCheck(IrOpcode::Value expected, Type from_type) {

14
test/mjsunit/regress/regress-901798.js Normal file
View File

@ -0,0 +1,14 @@
// Copyright 2018 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.
// Flags: --allow-natives-syntax
function f(a) {
return (a >>> 1073741824) + -3;
}
assertEquals(-3, f(0));
assertEquals(-2, f(1));
%OptimizeFunctionOnNextCall(f);
assertEquals(4294967291, f(-2));