[llvm] [IndVarSimplify] Set samesign when converting signed comparison to unsigned comparison in eliminateIVComparison. (PR #138215)

[Craig Topper via llvm-commits]

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@@ -57,14 +57,14 @@ define void @test_2(i32 %n, ptr %len_buf) {
 ; CHECK-SAME: (i32 [[N:%.*]], ptr [[LEN_BUF:%.*]]) {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[LEN:%.*]] = load i32, ptr [[LEN_BUF]], align 4, !range [[RNG1:![0-9]+]]
-; CHECK-NEXT:    [[TMP0:%.*]] = zext i32 [[LEN]] to i64
+; CHECK-NEXT:    [[TMP0:%.*]] = sext i32 [[LEN]] to i64
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topperc wrote:

This looks to be an interaction with the isSameSign check in WidenIV::widenLoopCompare

https://github.com/llvm/llvm-project/pull/138215