[DAGCombiner] Don't ignore N2's undef elements in `foldVSelectOfConst… · llvm/llvm-project@0064565 (original) (raw)

Original file line number	Diff line number	Diff line change
@@ -302,3 +302,21 @@ define i32 @wrong_min_signbits(<2 x i16> %x) {
302	302	%t1 = bitcast <2 x i16> %sel to i32
303	303	ret i32 %t1
304	304	}
	305	+
	306	+define i32 @pr129181() {
	307	+; SSE-LABEL: pr129181:
	308	+; SSE: # %bb.0: # %entry
	309	+; SSE-NEXT: xorl %eax, %eax
	310	+; SSE-NEXT: retq
	311	+;
	312	+; AVX-LABEL: pr129181:
	313	+; AVX: # %bb.0: # %entry
	314	+; AVX-NEXT: xorl %eax, %eax
	315	+; AVX-NEXT: retq
	316	+entry:
	317	+%x = insertelement <4 x i32> zeroinitializer, i32 0, i32 0
	318	+%cmp = icmp ult <4 x i32> %x, splat (i32 1)
	319	+%sel = select <4 x i1> %cmp, <4 x i32> zeroinitializer, <4 x i32> <i32 0, i32 0, i32 1, i32 poison>
	320	+%reduce = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %sel)
	321	+ret i32 %reduce
	322	+}