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@xxxxxxxxxxxxx> 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+
