dnl  AMD64 mpn_add_n, mpn_sub_n

dnl  Copyright 2003, 2004, 2005, 2007, 2008, 2010, 2011 Free Software
dnl  Foundation, Inc.

dnl  This file is part of the GNU MP Library.

dnl  The GNU MP Library is free software; you can redistribute it and/or modify
dnl  it under the terms of the GNU Lesser General Public License as published
dnl  by the Free Software Foundation; either version 3 of the License, or (at
dnl  your option) any later version.

dnl  The GNU MP Library is distributed in the hope that it will be useful, but
dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
dnl  License for more details.

dnl  You should have received a copy of the GNU Lesser General Public License
dnl  along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.

include(`../config.m4')

C	     cycles/limb
C AMD K8,K9	 1.5
C AMD K10	 1.5
C Intel P4	 ?
C Intel core2	 4.9
C Intel NHM	 5.5
C Intel SBR	 1.59
C Intel atom	 4
C VIA nano	 3.25

C The loop of this code is the result of running a code generation and
C optimization tool suite written by David Harvey and Torbjorn Granlund.

C INPUT PARAMETERS
define(`rp',	`%rdi')	C rcx
define(`up',	`%rsi')	C rdx
define(`vp',	`%rdx')	C r8
define(`n',	`%rcx')	C r9
define(`cy',	`%r8')	C rsp+40    (only for mpn_add_nc)

ifdef(`OPERATION_add_n', `
	define(ADCSBB,	      adc)
	define(func,	      mpn_add_n)
	define(func_nc,	      mpn_add_nc)')
ifdef(`OPERATION_sub_n', `
	define(ADCSBB,	      sbb)
	define(func,	      mpn_sub_n)
	define(func_nc,	      mpn_sub_nc)')

MULFUNC_PROLOGUE(mpn_add_n mpn_add_nc mpn_sub_n mpn_sub_nc)

ABI_SUPPORT(DOS64)
ABI_SUPPORT(STD64)

ASM_START()
	TEXT
	ALIGN(16)
PROLOGUE(func_nc)
	FUNC_ENTRY(4)
IFDOS(`	mov	56(%rsp), %r8	')
	mov	R32(n), R32(%rax)
	shr	$2, n
	and	$3, R32(%rax)
	bt	$0, %r8			C cy flag <- carry parameter
	jrcxz	L(lt4)

	mov	(up), %r8
	mov	8(up), %r9
	dec	n
	jmp	L(mid)

EPILOGUE()
	ALIGN(16)
PROLOGUE(func)
	FUNC_ENTRY(4)
	mov	R32(n), R32(%rax)
	shr	$2, n
	and	$3, R32(%rax)
	jrcxz	L(lt4)

	mov	(up), %r8
	mov	8(up), %r9
	dec	n
	jmp	L(mid)

L(lt4):	dec	R32(%rax)
	mov	(up), %r8
	jnz	L(2)
	ADCSBB	(vp), %r8
	mov	%r8, (rp)
	adc	R32(%rax), R32(%rax)
	FUNC_EXIT()
	ret

L(2):	dec	R32(%rax)
	mov	8(up), %r9
	jnz	L(3)
	ADCSBB	(vp), %r8
	ADCSBB	8(vp), %r9
	mov	%r8, (rp)
	mov	%r9, 8(rp)
	adc	R32(%rax), R32(%rax)
	FUNC_EXIT()
	ret

L(3):	mov	16(up), %r10
	ADCSBB	(vp), %r8
	ADCSBB	8(vp), %r9
	ADCSBB	16(vp), %r10
	mov	%r8, (rp)
	mov	%r9, 8(rp)
	mov	%r10, 16(rp)
	setc	R8(%rax)
	FUNC_EXIT()
	ret

	ALIGN(16)
L(top):	ADCSBB	(vp), %r8
	ADCSBB	8(vp), %r9
	ADCSBB	16(vp), %r10
	ADCSBB	24(vp), %r11
	mov	%r8, (rp)
	lea	32(up), up
	mov	%r9, 8(rp)
	mov	%r10, 16(rp)
	dec	n
	mov	%r11, 24(rp)
	lea	32(vp), vp
	mov	(up), %r8
	mov	8(up), %r9
	lea	32(rp), rp
L(mid):	mov	16(up), %r10
	mov	24(up), %r11
	jnz	L(top)

L(end):	lea	32(up), up
	ADCSBB	(vp), %r8
	ADCSBB	8(vp), %r9
	ADCSBB	16(vp), %r10
	ADCSBB	24(vp), %r11
	lea	32(vp), vp
	mov	%r8, (rp)
	mov	%r9, 8(rp)
	mov	%r10, 16(rp)
	mov	%r11, 24(rp)
	lea	32(rp), rp

	inc	R32(%rax)
	dec	R32(%rax)
	jnz	L(lt4)
	adc	R32(%rax), R32(%rax)
	FUNC_EXIT()
	ret
EPILOGUE()