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
diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index ce8ebbc..a0023fe 100644
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -171,6 +171,10 @@
}
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;