[DSE] Upgrade uses of MemoryIntrinic::getAlignment() to new API. (NFC)

Summary:
This change is part of step five in the series of changes to remove alignment argument from
memcpy/memmove/memset in favour of alignment attributes. In particular, this changes the
DeadStoreElimination pass to cease using the old getAlignment() API of MemoryIntrinsic
in favour of getting dest specific alignments through the new API.

Steps:
Step 1) Remove alignment parameter and create alignment parameter attributes for
memcpy/memmove/memset. ( rL322965, rC322964, rL322963 )
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
source and dest alignments. ( rL323597 )
Step 3) Update Clang to use the new IRBuilder API. ( rC323617 )
Step 4) Update Polly to use the new IRBuilder API. ( rL323618 )
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
and those that use use MemIntrinsicInst::[get|set]Alignment() to use [get|set]DestAlignment()
and [get|set]SourceAlignment() instead. ( rL323886, rL323891, rL324148, rL324273, rL324278,
rL324384, rL324395 )
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
MemIntrinsicInst::[get|set]Alignment() methods.

Reference
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324402 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/DeadStoreElimination.cpp b/lib/Transforms/Scalar/DeadStoreElimination.cpp
index 6c7d311..53ceb89 100644 (file)
--- a/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ b/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -876,7 +876,7 @@ static bool tryToShorten(Instruction *EarlierWrite, int64_t &EarlierOffset,
   // as any store/memset/memcpy is likely using vector instructions so
   // shortening it to not vector size is likely to be slower
   MemIntrinsic *EarlierIntrinsic = cast<MemIntrinsic>(EarlierWrite);
-  unsigned EarlierWriteAlign = EarlierIntrinsic->getAlignment();
+  unsigned EarlierWriteAlign = EarlierIntrinsic->getDestAlignment();
   if (!IsOverwriteEnd)
     LaterOffset = int64_t(LaterOffset + LaterSize);