From c9e8621268cc818bdde073e7fbbf25e78dc7cdb1 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 8 Mar 2010 23:49:12 +0000
Subject: [PATCH] Don't waste time trying to CSE labels, phis, inline asm.
 Definitely avoid cse implicit-def for obvious performance reason.

llvm-svn: 98009
---
 llvm/lib/CodeGen/MachineCSE.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/llvm/lib/CodeGen/MachineCSE.cpp b/llvm/lib/CodeGen/MachineCSE.cpp
index ce8ebbc60109..a0023feb986c 100644
--- a/llvm/lib/CodeGen/MachineCSE.cpp
+++ b/llvm/lib/CodeGen/MachineCSE.cpp
@@ -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;