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0ce38730ac
Use __builtin_clz() where available. Where it isn't, we can still win a little by using the pg_leftmost_one_pos[] lookup table instead of having a private table. Also drop the initial right shift by ALLOC_MINBITS in favor of subtracting ALLOC_MINBITS from the leftmost-one-pos result. This is a win because the compiler can fold that adjustment into other constants it'd have to add anyway, making the shift-removal free. Also, we can explain this coding as an unrolled form of pg_leftmost_one_pos32(), even though that's a bit ahistorical since it long predates pg_bitutils.h. John Naylor, with some cosmetic adjustments by me Discussion: https://postgr.es/m/CACPNZCuNUGMxjK7WTn_=WZnRbfASDdBxmjsVf2+m9MdmeNw_sg@mail.gmail.com |
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| error | ||
| fmgr | ||
| hash | ||
| init | ||
| mb | ||
| misc | ||
| mmgr | ||
| resowner | ||
| sort | ||
| time | ||
| .gitignore | ||
| errcodes.txt | ||
| Gen_dummy_probes.pl | ||
| Gen_dummy_probes.sed | ||
| Gen_fmgrtab.pl | ||
| generate-errcodes.pl | ||
| Makefile | ||
| probes.d | ||