Move this test a bit later, after the point at which we know that we either

have an alloca or a parameter, since then the alloca test should make sense
to readers, while before it probably appears too specific.  No functionality
change.

llvm-svn: 165306

diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index c02d4ce..fba4aae 100644 (file)
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -605,16 +605,6 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy,
   if (cpyLen < srcSize)
     return false;
 
-  // Check that dest points to memory that is at least as aligned as src.
-  unsigned srcAlign = srcAlloca->getAlignment();
-  if (!srcAlign)
-    srcAlign = TD->getABITypeAlignment(srcAlloca->getAllocatedType());
-  bool isDestSufficientlyAligned = srcAlign <= cpyAlign;
-  // If dest is not aligned enough and we can't increase its alignment then
-  // bail out.
-  if (!isDestSufficientlyAligned && !isa<AllocaInst>(cpyDest))
-    return false;
-
   // Check that accessing the first srcSize bytes of dest will not cause a
   // trap.  Otherwise the transform is invalid since it might cause a trap
   // to occur earlier than it otherwise would.
@@ -644,6 +634,16 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy,
     return false;
   }
 
+  // Check that dest points to memory that is at least as aligned as src.
+  unsigned srcAlign = srcAlloca->getAlignment();
+  if (!srcAlign)
+    srcAlign = TD->getABITypeAlignment(srcAlloca->getAllocatedType());
+  bool isDestSufficientlyAligned = srcAlign <= cpyAlign;
+  // If dest is not aligned enough and we can't increase its alignment then
+  // bail out.
+  if (!isDestSufficientlyAligned && !isa<AllocaInst>(cpyDest))
+    return false;
+
   // Check that src is not accessed except via the call and the memcpy.  This
   // guarantees that it holds only undefined values when passed in (so the final
   // memcpy can be dropped), that it is not read or written between the call and