kc3-lang/gnulib

2024-05-13T15:21:55

stdbit: redo clzll without lookcup table * lib/stdbit.c (__gl_stdbit_clztab): * lib/stdbit.in.h (__gl_stdbit_clzll): [!_GL_STDBIT_HAS_BUILTIN_CLZ && !_MSC_VER]: Rewrite to avoid the need for a lookup table in memory, and remove the lookup table. Do this by shrinking the table to 64 bits and puttiung in a 64-bit constant. Although this needs another round of shifts, it avoids the need for a multiplication and memory access a la de Bruijn, and is probably a win.