[AArch64LoadStoreOptimizer] Check aliasing correctly when creating paired loads/stores.

The existing code accidentally skipped the aliasing check in edge cases.

Differential revision: https://reviews.llvm.org/D23372

llvm-svn: 278562

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
index a2e0376c50b..dc07af6f5ad 100644
--- a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
@@ -1253,8 +1253,11 @@ AArch64LoadStoreOpt::findMatchingInsn(MachineBasicBlock::iterator I,
         if (MIIsUnscaled) {
           // If the unscaled offset isn't a multiple of the MemSize, we can't
           // pair the operations together: bail and keep looking.
-          if (MIOffset % MemSize)
+          if (MIOffset % MemSize) {
+            trackRegDefsUses(MI, ModifiedRegs, UsedRegs, TRI);
+            MemInsns.push_back(&MI);
             continue;
+          }
           MIOffset /= MemSize;
         } else {
           MIOffset *= MemSize;