added negative test

Author: Charukesh827

llvm/test/Transforms/InstCombine/shift-binop.ll

@@ -1,27 +1,29 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -passes=instcombine -S | FileCheck %s
 
-define i8 @src(i8 %arg0) {
-; CHECK-LABEL: @src(
-; CHECK-NEXT:    [[TMP1:%.*]] = shl nuw i8 [[ARG0:%.*]], 1
-; CHECK-NEXT:    [[TMP2:%.*]] = call i8 @llvm.umax.i8(i8 [[TMP1]], i8 16)
-; CHECK-NEXT:    ret i8 [[TMP2]]
+define i8 @src1(i8 %arg0) {
+; CHECK-LABEL: @src1(
+; CHECK-NEXT:    [[SHL:%.*]] = shl nuw i8 [[ARG0:%.*]], 1
+; CHECK-NEXT:    [[OUTMAX:%.*]] = call i8 @llvm.umax.i8(i8 [[SHL]], i8 16)
+; CHECK-NEXT:    ret i8 [[OUTMAX]]
 ;
   %1 = call i8 @llvm.umax.i8(i8 %arg0, i8 1)
   %2 = shl nuw i8 %1, 1
   %3 = call i8 @llvm.umax.i8(i8 %2, i8 16)
   ret i8 %3
 }
 
-define i8 @tgt(i8 %arg0) {
-; CHECK-LABEL: @tgt(
-; CHECK-NEXT:    [[TMP1:%.*]] = shl nuw i8 [[ARG0:%.*]], 1
-; CHECK-NEXT:    [[TMP2:%.*]] = call i8 @llvm.umax.i8(i8 [[TMP1]], i8 16)
-; CHECK-NEXT:    ret i8 [[TMP2]]
+define i8 @src2(i8 %arg0) {
+; CHECK-LABEL: @src2(
+; CHECK-NEXT:    [[INMAX:%.*]] = call i8 @llvm.umax.i8(i8 [[ARG0:%.*]], i8 4)
+; CHECK-NEXT:    [[SHL:%.*]] = shl nuw i8 [[INMAX:%.*]], 1
+; CHECK-NEXT:    [[OUTMAX:%.*]] = call i8 @llvm.umax.i8(i8 [[SHL]], i8 10)
+; CHECK-NEXT:    ret i8 [[OUTMAX]]
 ;
-  %1 = shl nuw i8 %arg0, 1
-  %2 = call i8 @llvm.umax.i8(i8 %1, i8 16)
-  ret i8 %2
+  %1 = call i8 @llvm.umax.i8(i8 %arg0, i8 4)
+  %2 = shl nuw i8 %1, 1
+  %3 = call i8 @llvm.umax.i8(i8 %2, i8 10)
+  ret i8 %3
 }
 
 declare i8 @llvm.umax.i8(i8, i8)