[llvm] [ConstraintElim] Add pre-commit tests for PR82271. NFC. (PR #82357)

[Yingwei Zheng via llvm-commits]

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@@ -0,0 +1,154 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -passes=constraint-elimination -S %s | FileCheck %s
+
+define i1 @cmp_sext(i32 %a, i32 %b){
+; CHECK-LABEL: define i1 @cmp_sext(
+; CHECK-SAME: i32 [[A:%.*]], i32 [[B:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[A]], [[B]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[THEN:%.*]], label [[ELSE:%.*]]
+; CHECK:       then:
+; CHECK-NEXT:    [[SA:%.*]] = sext i32 [[A]] to i64
+; CHECK-NEXT:    [[SB:%.*]] = sext i32 [[B]] to i64
+; CHECK-NEXT:    [[ADD:%.*]] = add nsw i64 [[SA]], 1
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp sge i64 [[SB]], [[ADD]]
+; CHECK-NEXT:    ret i1 [[CMP2]]
+; CHECK:       else:
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  %cmp = icmp slt i32 %a, %b
+  br i1 %cmp, label %then, label %else
+
+then:
+  %sa = sext i32 %a to i64
+  %sb = sext i32 %b to i64
+  %add = add nsw i64 %sa, 1
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dtcxzyw wrote:

The increment should be less than or equal to 1. Sorry for my mistake. I will fix it in #82344.


https://github.com/llvm/llvm-project/pull/82357