rjmccall added a comment. In D59744#1549229 <https://reviews.llvm.org/D59744#1549229>, @efriedma wrote:
> If we're going to insert emms instructions automatically, it doesn't really > make sense to do it in the frontend; the backend could figure out the most > efficient placement itself. (See lib/Target/X86/X86VZeroUpper.cpp, which > implements similar logic for AVX.) The part I'd be worried about is the > potential performance hit from calling emms in places where other compilers > wouldn't, for code using MMX intrinsics. It would certainly be simpler for the frontend if the backend did this — in fact, even if the "frontend" was going to do it, I would have suggested doing it as a pass over the emitted IR rather than a special case in IRGen. Anyway, I'm open to any reasonable option; at this point, I'm just laying out the basic requirements for getting this patch back in, because the current patch is invalid given LLVM's current requirements. Repository: rL LLVM CHANGES SINCE LAST ACTION https://reviews.llvm.org/D59744/new/ https://reviews.llvm.org/D59744 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
