ref: f39abb2923ac5faf55ce283e925671d639f3b9b9
dir: /sys/src/libmp/port/mpvectscmp.c/
#include "os.h" #include <mp.h> #include "dat.h" int mpvectscmp(mpdigit *a, int alen, mpdigit *b, int blen) { mpdigit x, y, z, v; int m, p; if(alen > blen){ v = 0; while(alen > blen) v |= a[--alen]; m = p = ((-v^v)|v)>>(Dbits-1); } else if(blen > alen){ v = 0; while(blen > alen) v |= b[--blen]; m = ((-v^v)|v)>>(Dbits-1); p = m^1; } else m = p = 0; while(alen-- > 0){ x = a[alen]; y = b[alen]; z = x - y; x = ~x; v = (((-z^z)|z)>>(Dbits-1)) & ~m; p = ((~((x&y)|(x&z)|(y&z))>>(Dbits-1)) & v) | (p & ~v); m |= v; } return (p-m) | m; }