ztrunc.c (560B)
1 /* See LICENSE file for copyright and license details. */ 2 #include "internals.h" 3 4 5 void 6 ztrunc(z_t a, z_t b, size_t bits) 7 { 8 size_t chars; 9 10 if (unlikely(zzero(b))) { 11 SET_SIGNUM(a, 0); 12 return; 13 } 14 15 chars = CEILING_BITS_TO_CHARS(bits); 16 a->used = MIN(chars, b->used); 17 if (unlikely(a->used < chars)) 18 bits = 0; 19 if (likely(a != b)) { 20 a->sign = b->sign; 21 ENSURE_SIZE(a, a->used); 22 zmemcpy(a->chars, b->chars, a->used); 23 } 24 bits = BITS_IN_LAST_CHAR(bits); 25 if (likely(bits)) 26 a->chars[a->used - 1] &= ((zahl_char_t)1 << bits) - 1; 27 28 TRIM_AND_ZERO(a); 29 }