[SLP][NFC]Add a test with the incorrect vectorization of smax with unsigned arg.

Author: alexey-bataev

llvm/test/Transforms/SLPVectorizer/RISCV/smax-unsigned-operand.ll

@@ -0,0 +1,31 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -S --passes=slp-vectorizer -mtriple=riscv64-unknown-linux-gnu -mattr=+v < %s | FileCheck %s
+target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
+target triple = "riscv64-unknown-linux-gnu"
+
+@e = global [2 x i8] zeroinitializer
+
+define void @main(ptr noalias %p) {
+; CHECK-LABEL: define void @main(
+; CHECK-SAME: ptr noalias [[P:%.*]]) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[P]], align 4
+; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <2 x i32> <i32 0, i32 poison>, i32 [[TMP0]], i32 1
+; CHECK-NEXT:    [[TMP2:%.*]] = call <2 x i32> @llvm.smax.v2i32(<2 x i32> [[TMP1]], <2 x i32> <i32 0, i32 1>)
+; CHECK-NEXT:    [[TMP3:%.*]] = trunc <2 x i32> [[TMP2]] to <2 x i8>
+; CHECK-NEXT:    store <2 x i8> [[TMP3]], ptr getelementptr inbounds ([11 x i8], ptr @e, i64 0, i64 4), align 1
+; CHECK-NEXT:    ret void
+;
+bb:
+  %conv.4 = zext i32 0 to i64
+  %cond.4 = tail call i64 @llvm.smax.i64(i64 %conv.4, i64 0)
+  %conv5.4 = trunc i64 %cond.4 to i8
+  store i8 %conv5.4, ptr getelementptr inbounds ([11 x i8], ptr @e, i64 0, i64 4), align 1
+  %0 = load i32, ptr %p, align 4
+  %conv.5 = zext i32 %0 to i64
+  %cond.5 = tail call i64 @llvm.smax.i64(i64 %conv.5, i64 1)
+  %conv5.5 = trunc i64 %cond.5 to i8
+  store i8 %conv5.5, ptr getelementptr inbounds ([11 x i8], ptr @e, i64 0, i64 5), align 1
+  ret void
+}
+