Reviewers: Kevin Millikin, Erik Corry, Description: Fix a missing peephole optimization in ia32 code exposed with Kevin's change.
Please review this at http://codereview.chromium.org/7117 Affected files: M src/assembler-ia32.cc Index: src/assembler-ia32.cc =================================================================== --- src/assembler-ia32.cc (revision 490) +++ src/assembler-ia32.cc (working copy) @@ -720,6 +720,23 @@ void Assembler::add(const Operand& dst, const Immediate& x) { + ASSERT(reloc_info_writer.last_pc() != NULL); + if (FLAG_push_pop_elimination && (reloc_info_writer.last_pc() <= last_pc_)) { + byte instr = last_pc_[0]; + if ((instr & 0xf8) == 0x50) { + // Last instruction was a push. Check whether this is a pop without a + // result. + if ((dst.is_reg(esp)) && + (x.x_ == kPointerSize) && (x.rmode_ == RelocInfo::NONE)) { + pc_ = last_pc_; + last_pc_ = NULL; + if (FLAG_print_push_pop_elimination) { + PrintF("%d push/pop(noreg) eliminated\n", pc_offset()); + } + return; + } + } + } EnsureSpace ensure_space(this); last_pc_ = pc_; emit_arith(0, dst, x); --~--~---------~--~----~------------~-------~--~----~ v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev -~----------~----~----~----~------~----~------~--~---
