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Fix an error in a keyed lookup stub - HeapNumbers treated as strings.

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Review URL: http://codereview.chromium.org/155924

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2527 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
whesse@chromium.org 2009-07-23 13:01:17 +00:00
parent 4196711d2e
commit 18c6337a2c
2 changed files with 61 additions and 4 deletions
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19
src/ia32/ic-ia32.cc
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@ -43,6 +43,10 @@ namespace internal {
// Helper function used to load a property from a dictionary backing storage.
// This function may return false negatives, so miss_label
// must always call a backup property load that is complete.
// This function is safe to call if the receiver has fast properties,
// or if name is not a symbol, and will jump to the miss_label in that case.
static void GenerateDictionaryLoad(MacroAssembler* masm, Label* miss_label,
Register r0, Register r1, Register r2,
Register name) {
@ -56,7 +60,7 @@ static void GenerateDictionaryLoad(MacroAssembler* masm, Label* miss_label,
//
// r2 - used to hold the capacity of the property dictionary.
//
// name - holds the name of the property and is unchanges.
// name - holds the name of the property and is unchanged.
Label done;
@ -274,13 +278,20 @@ void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
__ bind(&slow);
__ IncrementCounter(&Counters::keyed_load_generic_slow, 1);
KeyedLoadIC::Generate(masm, ExternalReference(Runtime::kKeyedGetProperty));
// Check if the key is a symbol that is not an array index.
__ bind(&check_string);
// The key is not a smi.
// Is it a string?
__ CmpObjectType(eax, FIRST_NONSTRING_TYPE, edx);
__ j(above_equal, &slow);
// Is the string an array index, with cached numeric value?
__ mov(ebx, FieldOperand(eax, String::kLengthOffset));
__ test(ebx, Immediate(String::kIsArrayIndexMask));
__ j(not_zero, &index_string, not_taken);
__ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
__ movzx_b(ebx, FieldOperand(ebx, Map::kInstanceTypeOffset));
// If the string is a symbol, do a quick inline probe of the receiver's
// dictionary, if it exists.
__ movzx_b(ebx, FieldOperand(exd, Map::kInstanceTypeOffset));
__ test(ebx, Immediate(kIsSymbolMask));
__ j(zero, &slow, not_taken);
// Probe the dictionary leaving result in ecx.

46
test/mjsunit/regress/regress-155924.js Normal file
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@ -0,0 +1,46 @@
// Copyright 2009 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.
// A HeapNumber with certain bits in the mantissa of the floating point
// value should not be able to masquerade as a string in a keyed lookup
// inline cache stub. See http://codereview.chromium.org/155924.
A = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
function foo() {
x = 1 << 26;
x = x * x;
// The following floating-point heap number has a second word similar
// to that of the string "5":
// 2^52 + index << cached_index_shift + cached_index_tag
x = x + (5 << 2) + (1 << 1);
return A[x];
}
assertEquals(undefined, foo(), "First lookup A[bad_float]");
assertEquals(undefined, foo(), "Second lookup A[bad_float]");
assertEquals(undefined, foo(), "Third lookup A[bad_float]");