From 3ae8c069900514c1785fe4a84b6cdb0157dff59e Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Wed, 2 Mar 2016 21:07:08 +0100 Subject: Add zand, zor, zxor, znot, zbtest, zsplit, and the newly introduced ztrunc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/ztrunc.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 src/ztrunc.c (limited to 'src/ztrunc.c') diff --git a/src/ztrunc.c b/src/ztrunc.c new file mode 100644 index 0000000..d4c31de --- /dev/null +++ b/src/ztrunc.c @@ -0,0 +1,31 @@ +/* See LICENSE file for copyright and license details. */ +#include "internals" + +#include +#include + + +void +ztrunc(z_t a, z_t b, size_t bits) +{ + zahl_char_t mask = 1; + size_t chars; + if (zzero(b)) { + SET_SIGNUM(a, 0); + } else { + chars = CEILING_BITS_TO_CHARS(bits); + a->sign = b->sign; + a->used = chars < b->used ? chars : b->used; + if (a->alloced < b->alloced) { + a->alloced = b->alloced; + a->chars = realloc(a->chars, b->alloced * sizeof(*(a->chars))); + } + memcpy(a->chars, b->chars, a->used * sizeof(*(a->chars))); + bits = BITS_IN_LAST_CHAR(bits); + if (bits) { + mask <<= bits; + mask -= 1; + a->chars[a->used - 1] &= mask; + } + } +} -- cgit v1.2.3-70-g09d2