Messages in this thread | | | Date | Wed, 31 May 2017 16:03:18 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v5 2/3] x86/asm: Add suffix macro for GEN_*_RMWcc() |
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On Wed, May 31, 2017 at 06:17:16AM -0700, Kees Cook wrote: > On Wed, May 31, 2017 at 4:13 AM, Peter Zijlstra <peterz@infradead.org> wrote: > > On Tue, May 30, 2017 at 02:39:51PM -0700, Kees Cook wrote: > >> The coming x86 refcount protection needs to be able to add trailing > >> instructions to the GEN_*_RMWcc() operations. This extracts the > >> difference between the goto/non-goto cases so the helper macros > >> can be defined outside the #ifdef cases. Additionally adds argument > >> naming to the resulting asm for referencing from suffixed > >> instructions, and adds clobbers for "cc", and "cx" to let suffixes > >> use _ASM_CX, and retain any set flags. > > > > Another option is to simply require __GCC_ASM_FLAG_OUTPUT__ for the fast > > refcount stuff. That would result in simpler and more readable code. > > What versions of GCC support that?
IIRC 6+
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