[PATCH] D99773: [InstCombine] when calling conventions are compatible, don't convert the call to undef idiom

Mon Apr 12 14:50:05 PDT 2021

ychen added a comment.

In D99773#2684148 <https://reviews.llvm.org/D99773#2684148>, @nikic wrote:

> I've temporarily reverted this change because it causes a significant compile-time regression, see https://llvm-compile-time-tracker.com/compare.php?from=4b7bad9eaea2233521a94f6b096aaa88dc584e23&to=f4d682d6ce6c5b3a41a0acf297507c82f5c21eef&stat=instructions. I assume that wasn't intentional.
>
> Looking at the code, what stands out to me is that you're now parsing the target triple eagerly, even though it is only needed if AAPCS is actually involved. Passing it into the function as StringRef instead of Triple is probably sufficient. (More generally, it might make sense to store a parsed target triple in the module...)

Thanks for the report. Passing Stringref does put it back to normal.
https://llvm-compile-time-tracker.com/compare.php?from=23b8264b5255efdc7c87c189feab04520a1979d5&to=69359ebeee6e3bd0e786a51ca542762d3aa4e606&stat=instructions

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D99773/new/

https://reviews.llvm.org/D99773