[PATCH] D64101: [LoopUnroll] fix cloning callbr

[Nick Desaulniers via Phabricator via llvm-commits]

nickdesaulniers added a subscriber: eli.friedman.
nickdesaulniers added a comment.

> it needs a "memory" clobber. I think this should be handled like regular inline assembly already in LLVM?

Neither GCC nor Clang prevent loop unrolling loops containing inline asm w/ "memory" clobber.  You can observe this with my godbolt link above and manually add `"memory"` to the 4 position in the asm statement.

> If there's some rule that distinguishes blockaddresses used in callbr from general blockaddresses, we should state that explicitly somewhere in LangRef.

I don't really understand what you're looking for @eli.friedman .  Should I add a statment along the lines of "blockaddresses may be rewritten during optimization passes to refer to the address of newly created blocks"?


Repository:
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  https://reviews.llvm.org/D64101/new/

https://reviews.llvm.org/D64101