From 3534b428629be185e096be99e3bd5fdfe32d5544 Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Thu, 18 Sep 2014 18:55:44 +0000 Subject: initial commit with rc for skalibs-2.0.0.0 --- src/libbiguint/bu_subc.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 src/libbiguint/bu_subc.c (limited to 'src/libbiguint/bu_subc.c') diff --git a/src/libbiguint/bu_subc.c b/src/libbiguint/bu_subc.c new file mode 100644 index 0000000..c26adca --- /dev/null +++ b/src/libbiguint/bu_subc.c @@ -0,0 +1,22 @@ +/* ISC license. */ + +/* OpenBSD needs that for EOVERFLOW. wtfbsdseriously */ +#define _BSD_SOURCE + +#include +#include +#include + +int bu_subc (uint32 *c, unsigned int cn, uint32 const *a, unsigned int an, uint32 const *b, unsigned int bn, register int carry) +{ + register unsigned int i = 0 ; + for (; i < cn ; i++) + { + register uint32 ai = (i < an) ? a[i] : 0 ; + register uint32 bi = (i < bn) ? b[i] : 0 ; + register uint32 ci = ai - bi - carry ; + carry = (carry || bi) && (ci > ai) ; + c[i] = ci ; + } + return carry ? (errno = EOVERFLOW, 0) : 1 ; +} -- cgit v1.2.3