diff --git a/llvm/test/Transforms/SLPVectorizer/X86/alternate-opcode-strict-bitwidth-than-main.ll b/llvm/test/Transforms/SLPVectorizer/X86/alternate-opcode-strict-bitwidth-than-main.ll
new file mode 100644
index 0000000000000..cc2e16e2b099b
--- /dev/null
+++ b/llvm/test/Transforms/SLPVectorizer/X86/alternate-opcode-strict-bitwidth-than-main.ll
@@ -0,0 +1,38 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -passes=slp-vectorizer -S -slp-threshold=-99999 -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+define float @test(i8 %0) {
+; CHECK-LABEL: define float @test(
+; CHECK-SAME: i8 [[TMP0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <2 x i8> <i8 poison, i8 0>, i8 [[TMP0]], i32 0
+; CHECK-NEXT:    [[TMP2:%.*]] = sext <2 x i8> [[TMP1]] to <2 x i16>
+; CHECK-NEXT:    [[TMP3:%.*]] = mul <2 x i16> [[TMP2]], <i16 2, i16 27>
+; CHECK-NEXT:    [[TMP4:%.*]] = lshr <2 x i16> [[TMP2]], <i16 2, i16 27>
+; CHECK-NEXT:    [[TMP5:%.*]] = shufflevector <2 x i16> [[TMP3]], <2 x i16> [[TMP4]], <2 x i32> <i32 0, i32 3>
+; CHECK-NEXT:    [[TMP9:%.*]] = extractelement <2 x i16> [[TMP5]], i32 0
+; CHECK-NEXT:    [[TMP6:%.*]] = sext i16 [[TMP9]] to i32
+; CHECK-NEXT:    [[TMP10:%.*]] = extractelement <2 x i16> [[TMP5]], i32 1
+; CHECK-NEXT:    [[TMP7:%.*]] = zext i16 [[TMP10]] to i32
+; CHECK-NEXT:    [[TMP8:%.*]] = or i32 [[TMP6]], [[TMP7]]
+; CHECK-NEXT:    switch i32 [[TMP8]], label %[[EXIT:.*]] [
+; CHECK-NEXT:      i32 0, label %[[EXIT]]
+; CHECK-NEXT:      i32 1, label %[[EXIT]]
+; CHECK-NEXT:    ]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret float 0.000000e+00
+;
+entry:
+  %1 = sext i8 0 to i32
+  %2 = lshr i32 %1, 27
+  %3 = sext i8 %0 to i32
+  %reass.add.epil = mul i32 %3, 2
+  %4 = or i32 %reass.add.epil, %2
+  switch i32 %4, label %exit [
+  i32 0, label %exit
+  i32 1, label %exit
+  ]
+
+exit:
+  ret float 0.000000e+00
+}