commit de7dea2e44ea59674acb5680482cd516c6fce3bb
author Evan Cheng <evan.cheng@apple.com> Wed May 12 23:59:42 2010 +0000
committer Evan Cheng <evan.cheng@apple.com> Wed May 12 23:59:42 2010 +0000
tree 29f136973962d916a72d2333d35ea712c04ccab0
parent 3519f9d7d179ac1a77a4721b2e5f8123f95af418

Do not attempt copy coalescing if the source and dest sub-register indices do not match.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103679 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/RegAllocLocal.cpp

diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp
index 0a14e29..6372559 100644
--- a/lib/CodeGen/RegAllocLocal.cpp
+++ b/lib/CodeGen/RegAllocLocal.cpp
@@ -846,7 +846,8 @@
     unsigned SrcCopyReg, DstCopyReg, SrcCopySubReg, DstCopySubReg;
     unsigned SrcCopyPhysReg = 0U;
     bool isCopy = TII->isMoveInstr(*MI, SrcCopyReg, DstCopyReg, 
-                                   SrcCopySubReg, DstCopySubReg);
+                                   SrcCopySubReg, DstCopySubReg) &&
+      SrcCopySubReg == DstCopySubReg;
     if (isCopy && TargetRegisterInfo::isVirtualRegister(SrcCopyReg))
       SrcCopyPhysReg = getVirt2PhysRegMapSlot(SrcCopyReg);
 
@@ -1154,7 +1155,8 @@
     // the register scavenger.  See pr4100.)
     if (TII->isMoveInstr(*MI, SrcCopyReg, DstCopyReg,
                          SrcCopySubReg, DstCopySubReg) &&
-        SrcCopyReg == DstCopyReg && DeadDefs.empty())
+        SrcCopyReg == DstCopyReg && SrcCopySubReg == DstCopySubReg &&
+        DeadDefs.empty())
       MBB.erase(MI);
   }