From 9cc9bfaf86510790c36198b033f241635614a8d0 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 10 May 2010 21:25:30 +0000
Subject: [PATCH] It's not safe to propagate implicit_def that defines part of
 a register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103436 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/ProcessImplicitDefs.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/CodeGen/ProcessImplicitDefs.cpp b/lib/CodeGen/ProcessImplicitDefs.cpp
index d7179b3e59c..75875d2835b 100644
--- a/lib/CodeGen/ProcessImplicitDefs.cpp
+++ b/lib/CodeGen/ProcessImplicitDefs.cpp
@@ -89,6 +89,8 @@ bool ProcessImplicitDefs::runOnMachineFunction(MachineFunction &fn) {
       MachineInstr *MI = &*I;
       ++I;
       if (MI->isImplicitDef()) {
+        if (MI->getOperand(0).getSubReg())
+          continue;
         unsigned Reg = MI->getOperand(0).getReg();
         ImpDefRegs.insert(Reg);
         if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
-- 
2.34.1