[llvm] [IndVarSimplify] [NFC] Fix incorrect test (PR #159683)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Florian Mayer (fmayer)

<details>
<summary>Changes</summary>

We would reenter the lloop with %i.04 being 0, so the usub would
overflow to -1. That does not appear to be the intent of the test.


---
Full diff: https://github.com/llvm/llvm-project/pull/159683.diff


1 Files Affected:

- (modified) llvm/test/Transforms/IndVarSimplify/X86/overflow-intrinsics.ll (+3-6) 


``````````diff
diff --git a/llvm/test/Transforms/IndVarSimplify/X86/overflow-intrinsics.ll b/llvm/test/Transforms/IndVarSimplify/X86/overflow-intrinsics.ll
index e678146c80af8..c7db8b962f3d6 100644
--- a/llvm/test/Transforms/IndVarSimplify/X86/overflow-intrinsics.ll
+++ b/llvm/test/Transforms/IndVarSimplify/X86/overflow-intrinsics.ll
@@ -109,12 +109,9 @@ for.body:                                         ; preds = %entry, %cont
   %0 = tail call { i32, i1 } @llvm.usub.with.overflow.i32(i32 %i.04, i32 1)
   %1 = extractvalue { i32, i1 } %0, 1
 
-; It is theoretically possible to prove this, but SCEV cannot
-; represent non-unsigned-wrapping subtraction operations.
-
 ; CHECK: for.body:
-; CHECK:  [[COND:%[^ ]+]] = extractvalue { i32, i1 } %1, 1
-; CHECK-NEXT:  br i1 [[COND]], label %trap, label %cont, !nosanitize !0
+; CHECK-NOT: @llvm.usub.with.overflow.i32
+; CHECK: br i1 false, label %trap, label %cont, !nosanitize !0
   br i1 %1, label %trap, label %cont, !nosanitize !{}
 
 trap:                                             ; preds = %for.body
@@ -123,7 +120,7 @@ trap:                                             ; preds = %for.body
 
 cont:                                             ; preds = %for.body
   %2 = extractvalue { i32, i1 } %0, 0
-  %cmp = icmp sgt i32 %2, -1
+  %cmp = icmp sgt i32 %2, 0
   br i1 %cmp, label %for.body, label %for.cond.cleanup
 }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/159683