InstCombine: Ensure select condition types are identical before merging

Selection conditions may be vectors or scalars.  Make sure InstCombine
doesn't indiscriminately assume that a select which is value dependent
on another select have identical select condition types.

This fixes PR22773.

llvm-svn: 231156

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/select-select.ll b/llvm/test/Transforms/InstCombine/select-select.ll
index 65820acf07b..768d1c47c20 100644
--- a/llvm/test/Transforms/InstCombine/select-select.ll
+++ b/llvm/test/Transforms/InstCombine/select-select.ll
@@ -21,4 +21,14 @@ define float @foo2(float %a) #0 {
   ret float %f
 }
 
+; CHECK-LABEL: @foo3
+define <2 x i32> @foo3(<2 x i1> %vec_bool, i1 %bool, <2 x i32> %V) {
+; CHECK: %[[sel0:.*]] = select <2 x i1> %vec_bool, <2 x i32> zeroinitializer, <2 x i32> %V
+; CHECK: %[[sel1:.*]] = select i1 %bool, <2 x i32> %[[sel0]], <2 x i32> %V
+; CHECK: ret <2 x i32> %[[sel1]]
+  %sel0 = select <2 x i1> %vec_bool, <2 x i32> zeroinitializer, <2 x i32> %V
+  %sel1 = select i1 %bool, <2 x i32> %sel0, <2 x i32> %V
+  ret <2 x i32> %sel1
+}
+
 attributes #0 = { nounwind readnone ssp uwtable }