ref: 0769956a24915cb1f30f6e720e2f2051e755d0e0
dir: /bitreverse.c/
#include "platform.h" uint32_t __builtin_bitreverse32(uint32_t x) { uint32_t m; x = (x >> 16) | (x << 16); m = 0xff00ff00; x = ((x & m) >> 8) | ((x & ~m) << 8); m = 0xf0f0f0f0; x = ((x & m) >> 4) | ((x & ~m) << 4); m = 0xcccccccc; x = ((x & m) >> 2) | ((x & ~m) << 2); m = 0xaaaaaaaa; x = ((x & m) >> 1) | ((x & ~m) << 1); return x; }