[CodeGen] Ignore debug uses in MachineCopyPropagation

Debug uses should not count as real uses, since the presence of debug
information could affect the generated code.

llvm-svn: 336803

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MachineCopyPropagation.cpp b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
index d3bdc772ae4..3bf8147a06c 100644
--- a/llvm/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
@@ -517,7 +517,7 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
       if (MO.isDef() && !MO.isEarlyClobber()) {
         Defs.push_back(Reg);
         continue;
-      } else if (MO.readsReg())
+      } else if (!MO.isDebug() && MO.readsReg())
         ReadRegister(Reg);
     }