AArch64LoadStoreOptimizer: Correctly clear kill flags

When promoting the Load of a Store-Load pair to a COPY all kill flags
between the store and the load need to be cleared.

rdar://30402435

Differential Revision: https://reviews.llvm.org/D30110

llvm-svn: 295512

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
index 443a14f7068..8ec726267e8 100644
--- a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
@@ -866,9 +866,11 @@ AArch64LoadStoreOpt::promoteLoadFromStore(MachineBasicBlock::iterator LoadI,
               .addImm(Imms);
     }
   }
-  StoreI->clearRegisterKills(StRt, TRI);
 
-  (void)BitExtMI;
+  // Clear kill flags between store and load.
+  for (MachineInstr &MI : make_range(StoreI->getIterator(),
+                                     BitExtMI->getIterator()))
+    MI.clearRegisterKills(StRt, TRI);
 
   DEBUG(dbgs() << "Promoting load by replacing :\n    ");
   DEBUG(StoreI->print(dbgs()));