Fix an overly strict assertion. Source register of a copy may not be killed, it may be killed by an implicit super-register use.

llvm-svn: 55762

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/VirtRegMap.cpp b/llvm/lib/CodeGen/VirtRegMap.cpp
index 890ecf984c6..4fd0ad44b05 100644
--- a/llvm/lib/CodeGen/VirtRegMap.cpp
+++ b/llvm/lib/CodeGen/VirtRegMap.cpp
@@ -1730,7 +1730,8 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
           SmallVector<unsigned, 2> KillRegs;
           InvalidateKills(MI, RegKills, KillOps, &KillRegs);
           if (MO.isDead() && !KillRegs.empty()) {
-            assert(KillRegs[0] == Dst);
+            // Source register or an implicit super-register use is killed.
+            assert(KillRegs[0] == Dst || TRI->isSubRegister(KillRegs[0], Dst));
             // Last def is now dead.
             TransferDeadness(&MBB, Dist, Src, RegKills, KillOps);
           }