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Test behavior of qNaN and sNaN

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BUG=v8:2607

Review URL: https://codereview.chromium.org/13470002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14133 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
dslomov@chromium.org 2013-04-04 09:31:24 +00:00
parent eee5884f8d
commit 370caca72c
2 changed files with 108 additions and 35 deletions
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40
src/ia32/code-stubs-ia32.cc
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@ -4525,6 +4525,7 @@ void ICCompareStub::GenerateGeneric(MacroAssembler* masm) {
// Identical objects can be compared fast, but there are some tricky cases
// for NaN and undefined.
Label generic_heap_number_comparison;
{
Label not_identical;
__ cmp(eax, edx);
@ -4541,12 +4542,11 @@ void ICCompareStub::GenerateGeneric(MacroAssembler* masm) {
__ bind(&check_for_nan);
}
// Test for NaN. Sadly, we can't just compare to factory->nan_value(),
// so we do the second best thing - test it ourselves.
Label heap_number;
// Test for NaN. Compare heap numbers in a general way,
// to hanlde NaNs correctly.
__ cmp(FieldOperand(edx, HeapObject::kMapOffset),
Immediate(masm->isolate()->factory()->heap_number_map()));
__ j(equal, &heap_number, Label::kNear);
__ j(equal, &generic_heap_number_comparison, Label::kNear);
if (cc != equal) {
// Call runtime on identical JSObjects. Otherwise return equal.
__ CmpObjectType(eax, FIRST_SPEC_OBJECT_TYPE, ecx);
@ -4555,37 +4555,6 @@ void ICCompareStub::GenerateGeneric(MacroAssembler* masm) {
__ Set(eax, Immediate(Smi::FromInt(EQUAL)));
__ ret(0);
__ bind(&heap_number);
// It is a heap number, so return non-equal if it's NaN and equal if
// it's not NaN.
// The representation of NaN values has all exponent bits (52..62) set,
// and not all mantissa bits (0..51) clear.
// We only accept QNaNs, which have bit 51 set.
// Read top bits of double representation (second word of value).
// Value is a QNaN if value & kQuietNaNMask == kQuietNaNMask, i.e.,
// all bits in the mask are set. We only need to check the word
// that contains the exponent and high bit of the mantissa.
STATIC_ASSERT(((kQuietNaNHighBitsMask << 1) & 0x80000000u) != 0);
__ mov(edx, FieldOperand(edx, HeapNumber::kExponentOffset));
__ Set(eax, Immediate(0));
// Shift value and mask so kQuietNaNHighBitsMask applies to topmost
// bits.
__ add(edx, edx);
__ cmp(edx, kQuietNaNHighBitsMask << 1);
if (cc == equal) {
STATIC_ASSERT(EQUAL != 1);
__ setcc(above_equal, eax);
__ ret(0);
} else {
Label nan;
__ j(above_equal, &nan, Label::kNear);
__ Set(eax, Immediate(Smi::FromInt(EQUAL)));
__ ret(0);
__ bind(&nan);
__ Set(eax, Immediate(Smi::FromInt(NegativeComparisonResult(cc))));
__ ret(0);
}
__ bind(&not_identical);
}
@ -4665,6 +4634,7 @@ void ICCompareStub::GenerateGeneric(MacroAssembler* masm) {
// Generate the number comparison code.
Label non_number_comparison;
Label unordered;
__ bind(&generic_heap_number_comparison);
if (CpuFeatures::IsSupported(SSE2)) {
CpuFeatureScope use_sse2(masm, SSE2);
CpuFeatureScope use_cmov(masm, CMOV);

103
test/mjsunit/nans.js Normal file
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@ -0,0 +1,103 @@
// 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.
// Flags: --allow-natives-syntax
// Test that both kinds of NaNs (signaling or quiet) do not signal
function TestAllModes(f) {
f(); // Runtime
f(); // IC
f(); // IC second time
%OptimizeFunctionOnNextCall(f);
f(); // hydrogen
}
function TestDoubleSignalingNan() {
// NaN with signal bit set
function f() {
var bytes = new Uint32Array([1, 0x7FF00000]);
var doubles = new Float64Array(bytes.buffer);
assertTrue(isNaN(doubles[0]));
assertTrue(isNaN(doubles[0]*2.0));
assertTrue(isNaN(doubles[0] + 0.5));
}
TestAllModes(f);
}
TestDoubleSignalingNan();
function TestDoubleQuietNan() {
// NaN with signal bit cleared
function f() {
var bytes = new Uint32Array([0, 0x7FF80000]);
var doubles = new Float64Array(bytes.buffer);
assertTrue(isNaN(doubles[0]));
assertTrue(isNaN(doubles[0]*2.0));
assertTrue(isNaN(doubles[0] + 0.5));
}
TestAllModes(f);
}
TestDoubleQuietNan();
function TestFloatSignalingNan() {
// NaN with signal bit set
function f() {
var bytes = new Uint32Array([0x7F800001]);
var floats = new Float32Array(bytes.buffer);
assertTrue(isNaN(floats[0]));
assertTrue(isNaN(floats[0]*2.0));
assertTrue(isNaN(floats[0] + 0.5));
}
TestAllModes(f);
}
TestFloatSignalingNan();
function TestFloatQuietNan() {
// NaN with signal bit cleared
function f() {
var bytes = new Uint32Array([0x7FC00000]);
var floats = new Float32Array(bytes.buffer);
assertTrue(isNaN(floats[0]));
assertTrue(isNaN(floats[0]*2.0));
assertTrue(isNaN(floats[0] + 0.5));
}
TestAllModes(f);
}
TestFloatQuietNan();