[PATCH] D59744: Fix i386 ABI "__m64" type bug

[Eli Friedman via Phabricator via cfe-commits]

efriedma added a comment.

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.


Repository:
  rL LLVM

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  https://reviews.llvm.org/D59744/new/

https://reviews.llvm.org/D59744