[CGP] Update MemIntrinsic alignment if possible

Previously it was only being done if shouldAlignPointerArgs() returned
true, which right now is only true for ARM targets.
Updating the argument alignment attributes of memcpy/memset intrinsics
if the underlying object has larger alignment can be beneficial even
when CGP didn't increase alignment (as can be seen from the test changes),
so invert the loop and if condition.

Differential Revision: https://reviews.llvm.org/D134281

1 files changed, 13 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index cf2b32c..355f5a2 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -2252,19 +2252,19 @@ bool CodeGenPrepare::optimizeCallInst(CallInst *CI, ModifyDT &ModifiedDT) {
           DL->getTypeAllocSize(GV->getValueType()) >= MinSize + Offset2)
         GV->setAlignment(PrefAlign);
     }
-    // If this is a memcpy (or similar) then we may be able to improve the
-    // alignment
-    if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(CI)) {
-      Align DestAlign = getKnownAlignment(MI->getDest(), *DL);
-      MaybeAlign MIDestAlign = MI->getDestAlign();
-      if (!MIDestAlign || DestAlign > *MIDestAlign)
-        MI->setDestAlignment(DestAlign);
-      if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
-        MaybeAlign MTISrcAlign = MTI->getSourceAlign();
-        Align SrcAlign = getKnownAlignment(MTI->getSource(), *DL);
-        if (!MTISrcAlign || SrcAlign > *MTISrcAlign)
-          MTI->setSourceAlignment(SrcAlign);
-      }
+  }
+  // If this is a memcpy (or similar) then we may be able to improve the
+  // alignment.
+  if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(CI)) {
+    Align DestAlign = getKnownAlignment(MI->getDest(), *DL);
+    MaybeAlign MIDestAlign = MI->getDestAlign();
+    if (!MIDestAlign || DestAlign > *MIDestAlign)
+      MI->setDestAlignment(DestAlign);
+    if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
+      MaybeAlign MTISrcAlign = MTI->getSourceAlign();
+      Align SrcAlign = getKnownAlignment(MTI->getSource(), *DL);
+      if (!MTISrcAlign || SrcAlign > *MTISrcAlign)
+        MTI->setSourceAlignment(SrcAlign);
     }
   }