From 3530fa9cd09f8db8101c4649cab03bcdf760c434 Mon Sep 17 00:00:00 2001
From: Fedor Indutny <fedor@indutny.com>
Date: Fri, 21 Dec 2012 17:52:00 +0000
Subject: [PATCH] deps: backport 4ed5fde4f from v8 upstream
Original commit message:
Fix x64 MathMinMax for negative untagged int32 arguments.
An untagged int32 has zeros in the upper half even if it is negative.
Using cmpq to compare such numbers will incorrectly ignore the sign.
BUG=164442
R=mvstanton@chromium.org
Review URL: https://chromiumcodereview.appspot.com/11665007
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@13273 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Signed-off-by: Fedor Indutny <fedor@indutny.com>
---
src/x64/lithium-codegen-x64.cc | 6 ++--
test/mjsunit/regress/regress-164442.js | 45 ++++++++++++++++++++++++++
2 files changed, 48 insertions(+), 3 deletions(-)
create mode 100644 test/mjsunit/regress/regress-164442.js
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index b461e62..ff01f44 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -1457,17 +1457,17 @@ void LCodeGen::DoMathMinMax(LMathMinMax* instr) {
if (right->IsConstantOperand()) {
Immediate right_imm =
Immediate(ToInteger32(LConstantOperand::cast(right)));
- __ cmpq(left_reg, right_imm);
+ __ cmpl(left_reg, right_imm);
__ j(condition, &return_left, Label::kNear);
__ movq(left_reg, right_imm);
} else if (right->IsRegister()) {
Register right_reg = ToRegister(right);
- __ cmpq(left_reg, right_reg);
+ __ cmpl(left_reg, right_reg);
__ j(condition, &return_left, Label::kNear);
__ movq(left_reg, right_reg);
} else {
Operand right_op = ToOperand(right);
- __ cmpq(left_reg, right_op);
+ __ cmpl(left_reg, right_op);
__ j(condition, &return_left, Label::kNear);
__ movq(left_reg, right_op);
}
diff --git a/test/mjsunit/regress/regress-164442.js b/test/mjsunit/regress/regress-164442.js
new file mode 100644
index 0000000..1160d87
--- /dev/null
+++ b/test/mjsunit/regress/regress-164442.js
@@ -0,0 +1,45 @@
+// Copyright 2012 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.
+
+// Flags: --allow-natives-syntax
+
+// Should not take a very long time (n^2 algorithms are bad)
+
+
+function ensureNotNegative(x) {
+ return Math.max(0, x | 0);
+}
+
+
+ensureNotNegative(1);
+ensureNotNegative(2);
+
+%OptimizeFunctionOnNextCall(ensureNotNegative);
+
+var r = ensureNotNegative(-1);
+
+assertEquals(0, r);
--
2.0.3