[llvm] [ConstraintElim] Simplify `MinMaxIntrinsic` (PR #75306)

[Yingwei Zheng via llvm-commits]

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@@ -341,6 +341,147 @@ end:
   ret i32 0
 }
 
+; Test from PR75155
+define i32 @simplify_smax_val(i32 %a, i32 %b) {
+; CHECK-LABEL: define i32 @simplify_smax_val
+; CHECK-SAME: (i32 [[A:%.*]], i32 [[B:%.*]]) {
+; CHECK-NEXT:  start:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[A]], [[B]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK:       then:
+; CHECK-NEXT:    [[ADD:%.*]] = add nsw i32 [[A]], 1
+; CHECK-NEXT:    ret i32 [[B]]
+; CHECK:       else:
+; CHECK-NEXT:    ret i32 -1
+;
+start:
+  %cmp = icmp slt i32 %a, %b
+  br i1 %cmp, label %then, label %else
+then:
+  %add = add nsw i32 %a, 1
+  %max = call i32 @llvm.smax.i32(i32 %b, i32 %add)
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dtcxzyw wrote:

Done.

https://github.com/llvm/llvm-project/pull/75306