ztrunc.c - libzahl - big integer library
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       ---
       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 }