Don't waste time trying to CSE labels, phis, inline asm. Definitely avoid cse implicit-def for obvious performance reason.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98009 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2010-03-08 23:49:12 +00:00
parent 6c3b8ac6c9
commit 5196018d9c

View File

@ -171,6 +171,10 @@ bool MachineCSE::hasLivePhysRegDefUse(MachineInstr *MI, MachineBasicBlock *MBB){
}
bool MachineCSE::isCSECandidate(MachineInstr *MI) {
if (MI->isLabel() || MI->isPHI() || MI->isImplicitDef() ||
MI->isKill() || MI->isInlineAsm())
return false;
// Ignore copies or instructions that read / write physical registers
// (except for dead defs of physical registers).
unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;