Fix a bug in DAGcombiner about zero-extend after setcc.

For AArch64 backend, if DAGCombiner see "sext(setcc)", it will
combine them together to a single setcc with extended value type.
Then if it see "zext(setcc)", it assumes setcc is Vxi1, and try to
create "(and (vsetcc), (1, 1, ...)". While setcc isn't Vxi1,
DAGcombiner will create wrong node and get wrong code emitted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198190 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 12 insertions, 1 deletions

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 68d0521e76..3b87922b78 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4970,7 +4970,8 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
   }
 
   if (N0.getOpcode() == ISD::SETCC) {
-    if (!LegalOperations && VT.isVector()) {
+    if (!LegalOperations && VT.isVector() &&
+        N0.getValueType().getVectorElementType() == MVT::i1) {
       // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
       // Only do this before legalize for now.
       EVT N0VT = N0.getOperand(0).getValueType();
diff --git a/test/CodeGen/AArch64/neon-shift-left-long.ll b/test/CodeGen/AArch64/neon-shift-left-long.ll
index d45c47685b..d10d551805 100644
--- a/test/CodeGen/AArch64/neon-shift-left-long.ll
+++ b/test/CodeGen/AArch64/neon-shift-left-long.ll
@@ -191,3 +191,13 @@ define <2 x i64> @test_ushll2_shl0_v4i32(<4 x i32> %a) {
   %tmp = zext <2 x i32> %1 to <2 x i64>
   ret <2 x i64> %tmp
 }
+
+define <8 x i16> @test_ushll_cmp(<8 x i8> %a, <8 x i8> %b) #0 {
+; CHECK: test_ushll_cmp:
+; CHECK: cmeq	{{v[0-9]+}}.8b, {{v[0-9]+}}.8b, {{v[0-9]+}}.8b
+; CHECK-NEXT: ushll	{{v[0-9]+}}.8h, {{v[0-9]+}}.8b, #0
+  %cmp.i = icmp eq <8 x i8> %a, %b
+  %vcgtz.i.i = sext <8 x i1> %cmp.i to <8 x i8>
+  %vmovl.i.i.i = zext <8 x i8> %vcgtz.i.i to <8 x i16>
+  ret <8 x i16> %vmovl.i.i.i
+}