From d6908dc4a23cbaf8c9bde979d08fbb7291e7652f Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 10 May 2010 21:25:30 +0000
Subject: It's not safe to propagate implicit_def that defines part of a
 register.

llvm-svn: 103436
---
 llvm/lib/CodeGen/ProcessImplicitDefs.cpp | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'llvm/lib/CodeGen/ProcessImplicitDefs.cpp')

diff --git a/llvm/lib/CodeGen/ProcessImplicitDefs.cpp b/llvm/lib/CodeGen/ProcessImplicitDefs.cpp
index d7179b3e59c..75875d2835b 100644
--- a/llvm/lib/CodeGen/ProcessImplicitDefs.cpp
+++ b/llvm/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)) {
-- 
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