It is not safe to sink an alloca into a stacksave/stackrestore pair, so don't do that. <rdar://problem/10352360>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143093 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 75fa011..874a135 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -1680,11 +1680,12 @@
if (isa<LandingPadInst>(I))
continue;
- // Don't sink static AllocaInsts out of the entry block, which would
- // turn them into dynamic allocas!
- if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
- if (AI->isStaticAlloca())
- continue;
+ // Don't sink alloca: we never want to sink static alloca's out of the
+ // entry block, and correctly sinking dynamic alloca's requires
+ // checks for stacksave/stackrestore intrinsics.
+ // FIXME: Refactor this check somehow?
+ if (isa<AllocaInst>(I))
+ continue;
// Determine if there is a use in or before the loop (direct or
// otherwise).