Revision: 3415 Author: [email protected] Date: Thu Dec 3 23:43:40 2009 Log: Better handling of allocation alignment in generated code
Calculate the aligned size of strings when allocating from generated code using kObjectAlignmentMask Add native code assert to make sure allocation from generated code keeps alignment. Review URL: http://codereview.chromium.org/462025 http://code.google.com/p/v8/source/detail?r=3415 Modified: /branches/bleeding_edge/src/ia32/codegen-ia32.cc /branches/bleeding_edge/src/ia32/macro-assembler-ia32.cc ======================================= --- /branches/bleeding_edge/src/ia32/codegen-ia32.cc Thu Dec 3 02:24:16 2009 +++ /branches/bleeding_edge/src/ia32/codegen-ia32.cc Thu Dec 3 23:43:40 2009 @@ -7091,7 +7091,7 @@ switch (op_) { case Token::ADD: { // Test for string arguments before calling runtime. - Label not_strings, both_strings, not_string1, string1; + Label not_strings, not_string1, string1; Result answer; __ mov(eax, Operand(esp, 2 * kPointerSize)); // First argument. __ mov(edx, Operand(esp, 1 * kPointerSize)); // Second argument. ======================================= --- /branches/bleeding_edge/src/ia32/macro-assembler-ia32.cc Wed Dec 2 23:56:21 2009 +++ /branches/bleeding_edge/src/ia32/macro-assembler-ia32.cc Thu Dec 3 23:43:40 2009 @@ -687,6 +687,11 @@ void MacroAssembler::UpdateAllocationTopHelper(Register result_end, Register scratch) { + if (FLAG_debug_code) { + test(result_end, Immediate(kObjectAlignmentMask)); + Check(zero, "Unaligned allocation in new space"); + } + ExternalReference new_space_allocation_top = ExternalReference::new_space_allocation_top_address(); @@ -826,15 +831,18 @@ Register scratch2, Register scratch3, Label* gc_required) { - // Calculate the number of words needed for the number of characters in the - // string + // Calculate the number of bytes needed for the characters in the string while + // observing object alignment. + ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) == 0); mov(scratch1, length); - add(Operand(scratch1), Immediate(1)); - shr(scratch1, 1); + ASSERT(kShortSize == 2); + shl(scratch1, 1); + add(Operand(scratch1), Immediate(kObjectAlignmentMask)); + and_(Operand(scratch1), Immediate(~kObjectAlignmentMask)); // Allocate two byte string in new space. AllocateInNewSpace(SeqTwoByteString::kHeaderSize, - times_4, + times_1, scratch1, result, scratch2, @@ -857,15 +865,17 @@ Register scratch2, Register scratch3, Label* gc_required) { - // Calculate the number of words needed for the number of characters in the - // string + // Calculate the number of bytes needed for the characters in the string while + // observing object alignment. + ASSERT((SeqAsciiString::kHeaderSize & kObjectAlignmentMask) == 0); mov(scratch1, length); - add(Operand(scratch1), Immediate(3)); - shr(scratch1, 2); + ASSERT(kCharSize == 1); + add(Operand(scratch1), Immediate(kObjectAlignmentMask)); + and_(Operand(scratch1), Immediate(~kObjectAlignmentMask)); // Allocate ascii string in new space. AllocateInNewSpace(SeqAsciiString::kHeaderSize, - times_4, + times_1, scratch1, result, scratch2, @@ -1383,11 +1393,15 @@ RecordComment(msg); } #endif + // Disable stub call restrictions to always allow cals to abort. + set_allow_stub_calls(true); + push(eax); push(Immediate(p0)); push(Immediate(reinterpret_cast<intptr_t>(Smi::FromInt(p1 - p0)))); CallRuntime(Runtime::kAbort, 2); // will not return here + int3(); } -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev
