[llvm-commits] [llvm] r165306 - /llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp

[Duncan Sands]

Author: baldrick
Date: Fri Oct  5 02:29:46 2012
New Revision: 165306

URL: http://llvm.org/viewvc/llvm-project?rev=165306&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp?rev=165306&r1=165305&r2=165306&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp Fri Oct  5 02:29:46 2012
@@ -605,16 +605,6 @@
   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 @@
     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