$FreeBSD: head/devel/llvm32/files/patch-svn-r170353 340725 2014-01-22 17:40:44Z mat $
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r170353 | chandlerc | 2012-12-17 18:48:07 +0000 (Mon, 17 Dec 2012) | 5 lines

Fix another SROA crasher, PR14601.

This was a silly oversight, we weren't pruning allocas which were used
by variable-length memory intrinsics from the set that could be widened
and promoted as integers. Fix that.
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Index: lib/Transforms/Scalar/SROA.cpp
===================================================================
--- lib/Transforms/Scalar/SROA.cpp	(revision 170352)
+++ lib/Transforms/Scalar/SROA.cpp	(revision 170353)
@@ -2150,7 +2150,7 @@
           !canConvertValue(TD, ValueTy, AllocaTy))
         return false;
     } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I->U->getUser())) {
-      if (MI->isVolatile())
+      if (MI->isVolatile() || !isa<Constant>(MI->getLength()))
         return false;
       if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(I->U->getUser())) {
         const AllocaPartitioning::MemTransferOffsets &MTO
Index: test/Transforms/SROA/basictest.ll
===================================================================
--- test/Transforms/SROA/basictest.ll	(revision 170352)
+++ test/Transforms/SROA/basictest.ll	(revision 170353)
@@ -1208,3 +1208,18 @@
   ret i32 %y
 ; CHECK: ret i32
 }
+
+define i32 @PR14601(i32 %x) {
+; Don't try to form a promotable integer alloca when there is a variable length
+; memory intrinsic.
+; CHECK: @PR14601
+
+entry:
+  %a = alloca i32
+; CHECK: alloca
+
+  %a.i8 = bitcast i32* %a to i8*
+  call void @llvm.memset.p0i8.i32(i8* %a.i8, i8 0, i32 %x, i32 1, i1 false)
+  %v = load i32* %a
+  ret i32 %v
+}