ReMat of load from stub in pic mode extends the life of pic base. Currently spiller doesn't do a good job of estimating the impact. Disable for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49059 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2008-04-01 23:26:12 +00:00
parent da2903f028
commit ffe2eb0120

View File

@ -37,6 +37,10 @@ namespace {
cl::desc("Print instructions that the allocator wants to"
" fuse, but the X86 backend currently can't"),
cl::Hidden);
cl::opt<bool>
ReMatPICStubLoad("remat-pic-stub-load",
cl::desc("Re-materialize load from stub in PIC mode"),
cl::init(false), cl::Hidden);
}
X86InstrInfo::X86InstrInfo(X86TargetMachine &tm)
@ -782,6 +786,8 @@ bool X86InstrInfo::isReallyTriviallyReMaterializable(MachineInstr *MI) const {
if (BaseReg == 0)
return true;
// Allow re-materialization of PIC load.
if (!ReMatPICStubLoad && MI->getOperand(4).isGlobal())
return false;
MachineRegisterInfo &MRI = MI->getParent()->getParent()->getRegInfo();
bool isPICBase = false;
for (MachineRegisterInfo::def_iterator I = MRI.def_begin(BaseReg),