Fix an invalid bitcast crash that occurs when doing a partial memset of a vector
alloca. Fixes part of <rdar://problem/9580800>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133336 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index bb4779b..38942dc 100644
--- a/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -521,10 +521,22 @@
// If this is a constant sized memset of a constant value (e.g. 0) we can
// handle it.
if (MemSetInst *MSI = dyn_cast<MemSetInst>(User)) {
- // Store of constant value and constant size.
- if (!isa<ConstantInt>(MSI->getValue()) ||
- !isa<ConstantInt>(MSI->getLength()))
+ // Store of constant value.
+ if (!isa<ConstantInt>(MSI->getValue()))
return false;
+
+ // Store of constant size.
+ ConstantInt *Len = dyn_cast<ConstantInt>(MSI->getLength());
+ if (!Len)
+ return false;
+
+ // If the size differs from the alloca, we can only convert the alloca to
+ // an integer bag-of-bits.
+ // FIXME: This should handle all of the cases that are currently accepted
+ // as vector element insertions.
+ if (Len->getZExtValue() != AllocaSize || Offset != 0)
+ ScalarKind = Integer;
+
IsNotTrivial = true; // Can't be mem2reg'd.
HadNonMemTransferAccess = true;
continue;