Hi, FWIW, I'd split the introduction of the helper and the use of it in snapmgr into separate patches.
On 2022-08-02 15:13:01 -0700, Nathan Bossart wrote: > diff --git a/src/include/c.h b/src/include/c.h > index d35405f191..2c1a47bc28 100644 > --- a/src/include/c.h > +++ b/src/include/c.h > @@ -371,6 +371,14 @@ typedef void (*pg_funcptr_t) (void); > #endif > #endif > > +/* > + * Are SSE2 intrinsics available? > + */ > +#if (defined(__x86_64__) || defined(_M_AMD64)) > +#include <emmintrin.h> > +#define USE_SSE2 > +#endif > + It doesn't strike me as a good idea to include this in every single translation unit in pg. That header (+dependencies) isn't small. I'm on board with normalizing defines for SSE availability somewhere central though. > +/* > + * pg_linearsearch_uint32 > + * > + * Returns the address of the first element in 'base' that equals 'key', or > + * NULL if no match is found. > + */ > +#ifdef USE_SSE2 > +pg_attribute_no_sanitize_alignment() > +#endif What's the deal with this annotation? Needs a comment. > +static inline uint32 * > +pg_linearsearch_uint32(uint32 key, uint32 *base, uint32 nelem) Hm. I suspect this could be a bit faster if we didn't search for the offset, but just for presence in the array? Most users don't need the offset. Greetings, Andres Freund
