From f86500bc4f9b0e7078df9a17b84e95fbf37080a7 Mon Sep 17 00:00:00 2001 From: Daniel Dunbar Date: Thu, 28 Apr 2011 21:23:31 +0000 Subject: Target/X86/MC: Add an option for disabling arith relaxation, for my own testing purposes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130438 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/X86AsmBackend.cpp | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'lib/Target/X86/X86AsmBackend.cpp') diff --git a/lib/Target/X86/X86AsmBackend.cpp b/lib/Target/X86/X86AsmBackend.cpp index 968bef073a..4d7d96dcb3 100644 --- a/lib/Target/X86/X86AsmBackend.cpp +++ b/lib/Target/X86/X86AsmBackend.cpp @@ -21,6 +21,7 @@ #include "llvm/MC/MCSectionELF.h" #include "llvm/MC/MCSectionMachO.h" #include "llvm/Object/MachOFormat.h" +#include "llvm/Support/CommandLine.h" #include "llvm/Support/ELF.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" @@ -28,6 +29,13 @@ #include "llvm/Target/TargetAsmBackend.h" using namespace llvm; +// Option to allow disabling arithmetic relaxation to workaround PR9807, which +// is useful when running bitwise comparison experiments on Darwin. We should be +// able to remove this once PR9807 is resolved. +static cl::opt +MCDisableArithRelaxation("mc-x86-disable-arith-relaxation", + cl::desc("Disable relaxation of arithmetic instruction for X86")); + static unsigned getFixupKindLog2Size(unsigned Kind) { switch (Kind) { default: assert(0 && "invalid fixup kind!"); @@ -201,6 +209,9 @@ bool X86AsmBackend::MayNeedRelaxation(const MCInst &Inst) const { if (getRelaxedOpcodeBranch(Inst.getOpcode()) != Inst.getOpcode()) return true; + if (MCDisableArithRelaxation) + return false; + // Check if this instruction is ever relaxable. if (getRelaxedOpcodeArith(Inst.getOpcode()) == Inst.getOpcode()) return false; -- cgit v1.2.3-18-g5258