Bug 28444: Fix assertion when extract_vector_elt has mismatched type

For some reason extract_vector_elt is sometimes allowed to have
a different result type than the vector element type.

llvm-svn: 274829

2 files changed, 28 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 54d348e8911..dc2ff6eb918 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -12408,7 +12408,7 @@ SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
   // on the constant elements already work.
   if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT &&
       EltNo == InVec.getOperand(2))
-    return InVec.getOperand(1);
+    return DAG.getAnyExtOrTrunc(InVec.getOperand(1), SDLoc(N), NVT);
 
   // Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
   // We only perform this optimization before the op legalization phase because
diff --git a/llvm/test/CodeGen/X86/pr28444.ll b/llvm/test/CodeGen/X86/pr28444.ll
new file mode 100644
index 00000000000..452f01c166b
--- /dev/null
+++ b/llvm/test/CodeGen/X86/pr28444.ll
@@ -0,0 +1,27 @@
+; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mcpu=corei7 < %s | FileCheck %s
+; https://llvm.org/bugs/show_bug.cgi?id=28444
+
+; extract_vector_elt is allowed to have a different result type than
+; the vector scalar type.
+; This uses both
+;  i8 = extract_vector_elt v1i1, Constant:i64<0>
+;  i1 = extract_vector_elt v1i1, Constant:i64<0>
+
+
+; CHECK-LABEL: {{^}}extractelt_mismatch_vector_element_type:
+; CHECK: movb $1, %al
+; CHECK: movb %al
+; CHECK: movb %al
+define void @extractelt_mismatch_vector_element_type(i32 %arg) {
+bb:
+  %tmp = icmp ult i32 %arg, 0
+  %tmp2 = insertelement <1 x i1> undef, i1 true, i32 0
+  %tmp3 = select i1 %tmp, <1 x i1> undef, <1 x i1> %tmp2
+  %tmp6 = extractelement <1 x i1> %tmp3, i32 0
+  br label %bb1
+
+bb1:
+  store volatile <1 x i1> %tmp3, <1 x i1>* undef
+  store volatile i1 %tmp6, i1* undef
+  ret void
+}