[PATCH] D110813: [LoopRotate] Forget SCEV values in RewriteUsesOfClonedInstructions

[Bjorn Pettersson via Phabricator via llvm-commits]

bjope added a comment.

In D110813#3045467 <https://reviews.llvm.org/D110813#3045467>, @bjope wrote:

> In D110813#3041983 <https://reviews.llvm.org/D110813#3041983>, @fhahn wrote:
>
>> It looks like the crash/differences may be caused by stale entries in the loop disposition cache. Are those caught by the checks in D110385 <https://reviews.llvm.org/D110385>?
>
> Yep. I've downloaded D110385 <https://reviews.llvm.org/D110385>, and used `verify<scalar-evolution>` after loop-rotate instead of  `print<scalar-evolution>`. Then I see this:
>
>   Cached block disposition of SCEV (trunc i32 %wide to i16) for basic block: 
>   loop.inner:                                       ; preds = %loop.inner, %loop.inner.ph
>     %iv = phi i16 [ %narrow, %loop.inner.ph ], [ %iv.plus, %loop.inner ]
>     %iv.promoted = zext i16 %iv to i32
>     %gep = getelementptr inbounds [11263 x i32], [11263 x i32]* @array, i32 0, i32 %iv.promoted
>     store i32 7, i32* %gep, align 1
>     %iv.plus = add i16 %iv, 1
>     %cmp = icmp ult i16 %iv.plus, 700
>     br i1 %cmp, label %loop.inner, label %loop.outer.latch
>    has changed!
>   Cached: 2
>   Actual: 0

But only for the RUN-lines that uses `print<scalar-evolution>` before loop-rotate. When using `loop(canon-freeze)` I get the same kind of crash in the verifier as when using the print pass.


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  https://reviews.llvm.org/D110813/new/

https://reviews.llvm.org/D110813