Fix a DAG combiner assertion failure when constant folding BUILD_VECTORS.

svn r139159 caused SelectionDAG::getConstant() to promote BUILD_VECTOR operands
with illegal types, even before type legalization.  For this testcase, that led
to one BUILD_VECTOR with i16 operands and another with promoted i32 operands,
which triggered the assertion.

llvm-svn: 142370

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/ARM/vector-DAGCombine.ll b/llvm/test/CodeGen/ARM/vector-DAGCombine.ll
index 81bdc44863b..1a97982eb0a 100644
--- a/llvm/test/CodeGen/ARM/vector-DAGCombine.ll
+++ b/llvm/test/CodeGen/ARM/vector-DAGCombine.ll
@@ -123,3 +123,13 @@ define void @orVec(<3 x i8>* %A) nounwind {
   ret void
 }
 
+; The following test was hitting an assertion in the DAG combiner when
+; constant folding the multiply because the "sext undef" was translated to
+; a BUILD_VECTOR with i32 0 operands, which did not match the i16 operands
+; of the other BUILD_VECTOR.
+define i16 @foldBuildVectors() {
+  %1 = sext <8 x i8> undef to <8 x i16>
+  %2 = mul <8 x i16> %1, <i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255, i16 255>
+  %3 = extractelement <8 x i16> %2, i32 0
+  ret i16 %3
+}