[PATCH] D123408: [InstCombine] Limit folding of cast into PHI

Fri Jun 10 09:04:21 PDT 2022

spatel added a comment.

In D123408#3572528 <https://reviews.llvm.org/D123408#3572528>, @mstorsjo wrote:

>> afa192cfb604 <https://reviews.llvm.org/rGafa192cfb6049a15c5542d132d500b910b802c74>
>
> That commit causes breakage for me - one file which used to compile in around a second now hangs (doesn't complete in many minutes at least).
>
> To reproduce, download https://martin.st/temp/remap-preproc.c and try to compile it with `clang -target x86_64-w64-mingw32 -w -c -O2 remap-preproc.c`.

I reverted that commit. I do have an updated patch that accounts for the problem pattern that caused the infinite loop (blame constant expressions...again). Between that and D127499 <https://reviews.llvm.org/D127499>, I think it's safe to abandon this patch.

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  https://reviews.llvm.org/D123408/new/

https://reviews.llvm.org/D123408