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

Fri Jun 10 00:05:39 PDT 2022

mstorsjo added a comment.

In D123408#3571386 <https://reviews.llvm.org/D123408#3571386>, @spatel wrote:

> In D123408#3571242 <https://reviews.llvm.org/D123408#3571242>, @syzaara wrote:
>
>> Oh nevermind, please ignore above comment, I see what you are saying now! That we can add a transformation which can convert:
>
> Right - see if the motivating example looks better with:
> 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`.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D123408/new/

https://reviews.llvm.org/D123408