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path: root/arch/i386/atomic_arch.h
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2018-04-19remove a_ctz_l from arch specific atomic_arch.hAndre McCurdy-3/+3
Update atomic.h to provide a_ctz_l in all cases (atomic_arch.h should now only provide a_ctz_32 and/or a_ctz_64). The generic version of a_ctz_32 now takes advantage of a_clz_32 if available and the generic a_ctz_64 now makes use of a_ctz_32.
2017-08-29add a_clz_64 helper functionSzabolcs Nagy-0/+7
counts leading zero bits of a 64bit int, undefined on zero input. (has nothing to do with atomics, added to atomic.h so target specific helper functions are together.) there is a logarithmic generic implementation and another in terms of a 32bit a_clz_32 on targets where that's available.
2016-03-29fix regression disabling use of pause instruction for x86 a_spinRich Felker-1/+1
commits e24984efd5c6ac5ea8e6cb6cd914fa8435d458bc and 16b55298dc4b6a54d287d7494e04542667ef8861 inadvertently disabled the a_spin implementations for i386, x86_64, and x32 by defining a macro named a_pause instead of a_spin. this should not have caused any functional regression, but it inhibited cpu relaxation while spinning for locks. bug reported by George Kulakowski.
2016-01-22clean up i386 atomics for new atomics frameworkRich Felker-66/+58
this commit mostly makes consistent things like spacing, function ordering in atomic_arch.h, argument names, use of volatile, etc. the fake 64-bit and/or atomics are also removed because the shared atomic.h does a better job of implementing them; it avoids making two atomic memory accesses when only one 32-bit half needs to be touched. no major overhaul is needed or possible because x86 actually has native versions of all the usual atomic operations, rather than using ll/sc or needing cas loops.
2016-01-21refactor internal atomic.hRich Felker-0/+109
rather than having each arch provide its own atomic.h, there is a new shared atomic.h in src/internal which pulls arch-specific definitions from arc/$(ARCH)/atomic_arch.h. the latter can be extremely minimal, defining only a_cas or new ll/sc type primitives which the shared atomic.h will use to construct everything else. this commit avoids making heavy changes to the individual archs' atomic implementations. definitions which are identical or near-identical to what the new shared atomic.h would produce have been removed, but otherwise the changes made are just hooking up the arch-specific files to the new infrastructure. major changes to take advantage of the new system will come in subsequent commits.