[SLP][NFC]Add a test for final vector with minbitwidth, NFC.

Author: alexey-bataev

llvm/test/Transforms/SLPVectorizer/X86/minbitwidth-multiuse-with-insertelement.ll

@@ -0,0 +1,33 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -passes=slp-vectorizer -S -slp-threshold=-10 -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+define void @test(i8 %0) {
+; CHECK-LABEL: define void @test(
+; CHECK-SAME: i8 [[TMP0:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <2 x i8> <i8 0, i8 poison>, i8 [[TMP0]], i32 1
+; CHECK-NEXT:    [[TMP2:%.*]] = sext <2 x i8> [[TMP1]] to <2 x i32>
+; CHECK-NEXT:    [[TMP3:%.*]] = mul <2 x i32> [[TMP2]], zeroinitializer
+; CHECK-NEXT:    [[TMP4:%.*]] = extractelement <2 x i32> [[TMP3]], i32 0
+; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <2 x i32> [[TMP3]], i32 1
+; CHECK-NEXT:    [[ADD:%.*]] = or i32 [[TMP4]], [[TMP5]]
+; CHECK-NEXT:    [[SHR:%.*]] = lshr i32 [[ADD]], 1
+; CHECK-NEXT:    [[CONV9:%.*]] = trunc i32 [[SHR]] to i8
+; CHECK-NEXT:    store i8 [[CONV9]], ptr null, align 1
+; CHECK-NEXT:    [[TMP6:%.*]] = shufflevector <2 x i32> [[TMP2]], <2 x i32> poison, <8 x i32> <i32 1, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison>
+; CHECK-NEXT:    ret void
+;
+entry:
+  %conv3 = sext i8 %0 to i32
+  %conv7 = sext i8 0 to i32
+  %conv = zext i16 0 to i32
+  %mul = mul i32 %conv3, %conv
+  %conv6 = zext i16 0 to i32
+  %mul8 = mul i32 %conv7, %conv6
+  %add = or i32 %mul8, %mul
+  %shr = lshr i32 %add, 1
+  %conv9 = trunc i32 %shr to i8
+  store i8 %conv9, ptr null, align 1
+  %broadcast.splatinsert = insertelement <8 x i32> poison, i32 %conv3, i64 0
+  ret void
+}