dnl  x86-64 mpn_add_n/mpn_sub_n optimized for Pentium 4.

dnl  Contributed to the GNU project by Torbjorn Granlund.

dnl  Copyright 2007, 2008, 2010-2012 Free Software Foundation, Inc.

dnl  This file is part of the GNU MP Library.

dnl

dnl  The GNU MP Library is free software; you can redistribute it and/or modify

dnl  it under the terms of either:

dnl

dnl    * the GNU Lesser General Public License as published by the Free

dnl      Software Foundation; either version 3 of the License, or (at your

dnl      option) any later version.

dnl

dnl  or

dnl

dnl    * the GNU General Public License as published by the Free Software

dnl      Foundation; either version 2 of the License, or (at your option) any

dnl      later version.

dnl

dnl  or both in parallel, as here.

dnl

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 General Public License

dnl  for more details.

dnl

dnl  You should have received copies of the GNU General Public License and the

dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,

dnl  see https://www.gnu.org/licenses/.

include(`../config.m4')

C	     cycles/limb

C AMD K8,K9	 2.8

C AMD K10	 2.8

C Intel P4	 4

C Intel core2	 3.6-5	(fluctuating)

C Intel corei	 ?

C Intel atom	 ?

C VIA nano	 ?

C INPUT PARAMETERS

define(`rp',	`%rdi')

define(`up',	`%rsi')

define(`vp',	`%rdx')

define(`n',	`%rcx')

define(`cy',	`%r8')

ifdef(`OPERATION_add_n', `

	define(ADDSUB,	      add)

	define(func,	      mpn_add_n)

	define(func_nc,	      mpn_add_nc)')

ifdef(`OPERATION_sub_n', `

	define(ADDSUB,	      sub)

	define(func,	      mpn_sub_n)

	define(func_nc,	      mpn_sub_nc)')

ABI_SUPPORT(DOS64)

ABI_SUPPORT(STD64)

MULFUNC_PROLOGUE(mpn_add_n mpn_add_nc mpn_sub_n mpn_sub_nc)

ASM_START()

	TEXT

PROLOGUE(func)

	FUNC_ENTRY(4)

	xor	%r8, %r8

IFDOS(`	jmp	L(ent)		')

EPILOGUE()

PROLOGUE(func_nc)

	FUNC_ENTRY(4)

IFDOS(`	mov	56(%rsp), %r8	')

L(ent):	push	%rbx

	push	%r12

	mov	(vp), %r9

	mov	R32(n), R32(%rax)

	and	$3, R32(%rax)

	jne	L(n00)		C n = 0, 4, 8, ...

	mov	R32(%r8), R32(%rbx)

	mov	(up), %r8

	mov	8(up), %r10

	ADDSUB	%r9, %r8

	mov	8(vp), %r9

	setc	R8(%rax)

	lea	-16(rp), rp

	jmp	L(L00)

L(n00):	cmp	$2, R32(%rax)

	jnc	L(n01)		C n = 1, 5, 9, ...

	mov	(up), %r11

	mov	R32(%r8), R32(%rax)

	xor	R32(%rbx), R32(%rbx)

	dec	n

	jnz	L(gt1)

	ADDSUB	%r9, %r11

	setc	R8(%rbx)

	ADDSUB	%rax, %r11

	adc	$0, R32(%rbx)

	mov	%r11, (rp)

	jmp	L(ret)

L(gt1):	mov	8(up), %r8

	ADDSUB	%r9, %r11

	mov	8(vp), %r9

	setc	R8(%rbx)

	lea	-8(rp), rp

	lea	8(up), up

	lea	8(vp), vp

	jmp	L(L01)

L(n01):	jne	L(n10)		C n = 2, 6, 10, ...

	mov	(up), %r12

	mov	R32(%r8), R32(%rbx)

	mov	8(up), %r11

	ADDSUB	%r9, %r12

	mov	8(vp), %r9

	setc	R8(%rax)

	lea	-32(rp), rp

	lea	16(up), up

	lea	16(vp), vp

	jmp	L(L10)

L(n10):	mov	(up), %r10	C n = 3, 7, 11, ...

	mov	R32(%r8), R32(%rax)

	xor	R32(%rbx), R32(%rbx)

	mov	8(up), %r12

	ADDSUB	%r9, %r10

	mov	8(vp), %r9

	setc	R8(%rbx)

	lea	-24(rp), rp

	lea	-8(up), up

	lea	-8(vp), vp

	jmp	L(L11)

L(c0):	mov	$1, R8(%rbx)

	jmp	L(rc0)

L(c1):	mov	$1, R8(%rax)

	jmp	L(rc1)

L(c2):	mov	$1, R8(%rbx)

	jmp	L(rc2)

L(c3):	mov	$1, R8(%rax)

	jmp	L(rc3)

	ALIGN(16)

L(top):	mov	(up), %r8	C not on critical path

	ADDSUB	%r9, %r11	C not on critical path

	mov	(vp), %r9	C not on critical path

	setc	R8(%rbx)	C save carry out

	mov	%r12, (rp)

L(L01):	ADDSUB	%rax, %r11	C apply previous carry out

	jc	L(c0)		C jump if ripple

L(rc0):	mov	8(up), %r10

	ADDSUB	%r9, %r8

	mov	8(vp), %r9

	setc	R8(%rax)

	mov	%r11, 8(rp)

L(L00):	ADDSUB	%rbx, %r8

	jc	L(c1)

L(rc1):	mov	16(up), %r12

	ADDSUB	%r9, %r10

	mov	16(vp), %r9

	setc	R8(%rbx)

	mov	%r8, 16(rp)

L(L11):	ADDSUB	%rax, %r10

	jc	L(c2)

L(rc2):	mov	24(up), %r11

	ADDSUB	%r9, %r12

	lea	32(up), up

	mov	24(vp), %r9

	lea	32(vp), vp

	setc	R8(%rax)

	mov	%r10, 24(rp)

L(L10):	ADDSUB	%rbx, %r12

	jc	L(c3)

L(rc3):	lea	32(rp), rp

	sub	$4, n

	ja	L(top)

L(end):	ADDSUB	%r9, %r11

	setc	R8(%rbx)

	mov	%r12, (rp)

	ADDSUB	%rax, %r11

	jnc	L(1)

	mov	$1, R8(%rbx)

L(1):	mov	%r11, 8(rp)

L(ret):	mov	R32(%rbx), R32(%rax)

	pop	%r12

	pop	%rbx

	FUNC_EXIT()

	ret

EPILOGUE()