From: dslomov@chromium.org Date: Thu, 4 Apr 2013 09:31:24 +0000 (+0000) Subject: Test behavior of qNaN and sNaN X-Git-Tag: upstream/4.7.83~14704 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=370caca72c727ddbdd1e1627b088f6185d4e1516;p=platform%2Fupstream%2Fv8.git Test behavior of qNaN and sNaN 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 --- diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc index 09012b6..9b77c50 100644 --- a/src/ia32/code-stubs-ia32.cc +++ b/src/ia32/code-stubs-ia32.cc @@ -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(¬_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); diff --git a/test/mjsunit/nans.js b/test/mjsunit/nans.js new file mode 100644 index 0000000..d212afd --- /dev/null +++ b/test/mjsunit/nans.js @@ -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(); + + + +