/* AMD64 (x86_64) sub_n -- Subtract two limb vectors of the same length > 0 and store
* sum in a third limb vector.
*
* Copyright (C) 1992, 1994, 1995, 1998,
* 2001, 2002, 2006 Free Software Foundation, Inc.
*
* This file is part of Libgcrypt.
*
* Libgcrypt is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* Libgcrypt is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*
* Note: This code is heavily based on the GNU MP Library.
* Actually it's the same code with only minor changes in the
* way the data is stored; this is to support the abstraction
* of an optional secure memory allocation which may be used
* to avoid revealing of sensitive data due to paging etc.
*/
#include "sysdep.h"
#include "asm-syntax.h"
/*******************
* mpi_limb_t
* _gcry_mpih_sub_n( mpi_ptr_t res_ptr, rdi
* mpi_ptr_t s1_ptr, rsi
* mpi_ptr_t s2_ptr, rdx
* mpi_size_t size) rcx
*/
.text
.globl C_SYMBOL_NAME(_gcry_mpih_sub_n)
C_SYMBOL_NAME(_gcry_mpih_sub_n:)
FUNC_ENTRY()
leaq (%rsi,%rcx,8), %rsi
leaq (%rdi,%rcx,8), %rdi
leaq (%rdx,%rcx,8), %rdx
negq %rcx
xorl %eax, %eax /* clear cy */
ALIGN(4) /* minimal alignment for claimed speed */
.Loop: movq (%rsi,%rcx,8), %rax
movq (%rdx,%rcx,8), %r10
sbbq %r10, %rax
movq %rax, (%rdi,%rcx,8)
incq %rcx
jne .Loop
movq %rcx, %rax /* zero %rax */
adcq %rax, %rax
FUNC_EXIT()
ret
