[X86] Pre-commit test for pr90668. NFC

Author: topperc

llvm/test/CodeGen/X86/pr90688.ll

@@ -0,0 +1,15 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
+; RUN: llc < %s -mtriple=x86_64-linux-gnu | FileCheck %s
+
+define i64 @off(i8 signext %a) {
+; CHECK-LABEL: off:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    movzbl %dil, %eax
+; CHECK-NEXT:    leal 1024(,%rax,8), %eax
+; CHECK-NEXT:    retq
+entry:
+  %add = xor i8 %a, -128
+  %conv2 = zext i8 %add to i64
+  %mul = shl nuw nsw i64 %conv2, 3
+  ret i64 %mul
+}