2023-09-03 18:11:42 -07:00

85 lines
2.0 KiB
C

/* $OpenBSD: bn_arch.h,v 1.7 2023/04/17 12:51:09 jsing Exp $ */
/*
* Copyright (c) 2023 Joel Sing <jsing@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <openssl/bn.h>
#ifndef HEADER_BN_ARCH_H
#define HEADER_BN_ARCH_H
#ifndef OPENSSL_NO_ASM
#if defined(__GNUC__)
#define HAVE_BN_ADDW
static inline void
bn_addw(BN_ULONG a, BN_ULONG b, BN_ULONG *out_r1, BN_ULONG *out_r0)
{
BN_ULONG carry, r0;
__asm__ (
"adds %[r0], %[a], %[b] \n"
"cset %[carry], cs \n"
: [carry]"=r"(carry), [r0]"=r"(r0)
: [a]"r"(a), [b]"r"(b)
: "cc");
*out_r1 = carry;
*out_r0 = r0;
}
#define HAVE_BN_MULW
static inline void
bn_mulw(BN_ULONG a, BN_ULONG b, BN_ULONG *out_r1, BN_ULONG *out_r0)
{
BN_ULONG r1, r0;
/* Unsigned multiplication using a umulh/mul pair. */
__asm__ (
"umulh %[r1], %[a], %[b] \n"
"mul %[r0], %[a], %[b] \n"
: [r1]"=&r"(r1), [r0]"=r"(r0)
: [a]"r"(a), [b]"r"(b));
*out_r1 = r1;
*out_r0 = r0;
}
#define HAVE_BN_SUBW
static inline void
bn_subw(BN_ULONG a, BN_ULONG b, BN_ULONG *out_borrow, BN_ULONG *out_r0)
{
BN_ULONG borrow, r0;
__asm__ (
"subs %[r0], %[a], %[b] \n"
"cset %[borrow], cc \n"
: [borrow]"=r"(borrow), [r0]"=r"(r0)
: [a]"r"(a), [b]"r"(b)
: "cc");
*out_borrow = borrow;
*out_r0 = r0;
}
#endif /* __GNUC__ */
#endif
#endif