[SystemZ] Bugfix in combineSTORE().

Remember to check if store is truncating before calling
combineTruncateExtract().

Review: Ulrich Weigand
llvm-svn: 333262

2 files changed, 20 insertions, 1 deletions

diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
index 14a96389698..e69afd8a36a 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -5357,7 +5357,7 @@ SDValue SystemZTargetLowering::combineSTORE(
   // for the extraction to be done on a vMiN value, so that we can use VSTE.
   // If X has wider elements then convert it to:
   // (truncstoreiN (extract_vector_elt (bitcast X), Y2), Z).
-  if (MemVT.isInteger()) {
+  if (MemVT.isInteger() && SN->isTruncatingStore()) {
     if (SDValue Value =
             combineTruncateExtract(SDLoc(N), MemVT, SN->getValue(), DCI)) {
       DCI.AddToWorklist(Value.getNode());
diff --git a/llvm/test/CodeGen/SystemZ/dag-combine-04.ll b/llvm/test/CodeGen/SystemZ/dag-combine-04.ll
new file mode 100644
index 00000000000..4837c462d5e
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/dag-combine-04.ll
@@ -0,0 +1,19 @@
+; Test that SystemZTargetLowering::combineSTORE() does not crash due to not
+; checking if store is actually a truncating store before calling
+; combineTruncateExtract().
+;
+; RUN: llc -mtriple=s390x-linux-gnu -mcpu=z13 < %s
+
+@g_348 = external dso_local unnamed_addr global [6 x [10 x i16]], align 2
+
+define void @main() local_unnamed_addr {
+bb:
+  %tmp = load i16, i16* getelementptr inbounds ([6 x [10 x i16]], [6 x [10 x i16]]* @g_348, i64 0, i64 1, i64 6), align 2
+  %tmp1 = xor i16 %tmp, 0
+  %tmp2 = insertelement <2 x i16> <i16 undef, i16 0>, i16 %tmp1, i32 0
+  %tmp3 = shufflevector <2 x i16> %tmp2, <2 x i16> undef, <2 x i32> <i32 1, i32 undef>
+  %tmp4 = xor <2 x i16> %tmp2, %tmp3
+  %tmp5 = extractelement <2 x i16> %tmp4, i32 0
+  store i16 %tmp5, i16* getelementptr inbounds ([6 x [10 x i16]], [6 x [10 x i16]]* @g_348, i64 0, i64 1, i64 6), align 2
+  unreachable
+}