dnl  AMD64 mpn_mod_34lsub1 -- remainder modulo 2^48-1.

dnl  Copyright 2000-2002, 2004, 2005, 2007, 2009-2012 Free Software Foundation,

dnl  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	 0.67	   0.583 is possible with zero-reg instead of $0, 4-way

C AMD K10	 0.67	   this seems hard to beat

C AMD bd1	 1

C AMD bobcat	 1.07

C Intel P4	 7.35	   terrible, use old code

C Intel core2	 1.25	   1+epsilon with huge unrolling

C Intel NHM	 1.15	   this seems hard to beat

C Intel SBR	 0.93

C Intel atom	 2.5

C VIA nano	 1.25	   this seems hard to beat

C INPUT PARAMETERS

define(`ap',	%rdi)

define(`n',	%rsi)

C mp_limb_t mpn_mod_34lsub1 (mp_srcptr up, mp_size_t n)

C TODO

C  * Review feed-in and wind-down code.

ABI_SUPPORT(DOS64)

ABI_SUPPORT(STD64)

ASM_START()

	TEXT

	ALIGN(32)

PROLOGUE(mpn_mod_34lsub1)

	FUNC_ENTRY(2)

	mov	$0x0000FFFFFFFFFFFF, %r11

	mov	(ap), %rax

	cmp	$2, %rsi

	ja	L(gt2)

	jb	L(one)

	mov	8(ap), %rsi

	mov	%rax, %rdx

	shr	$48, %rax		C src[0] low

	and	%r11, %rdx		C src[0] high

	add	%rdx, %rax

	mov	R32(%rsi), R32(%rdx)

	shr	$32, %rsi		C src[1] high

	add	%rsi, %rax

	shl	$16, %rdx		C src[1] low

	add	%rdx, %rax

L(one):	FUNC_EXIT()

	ret

C Don't change this, the wind-down code is not able to handle greater values

define(UNROLL,3)

L(gt2):	mov	8(ap), %rcx

	mov	16(ap), %rdx

	xor	%r9, %r9

	add	$24, ap

	sub	$eval(UNROLL*3+3), %rsi

	jc	L(end)

	ALIGN(16)

L(top):

	add	(ap), %rax

	adc	8(ap), %rcx

	adc	16(ap), %rdx

	adc	$0, %r9

forloop(i,1,UNROLL-1,`dnl

	add	eval(i*24)(ap), %rax

	adc	eval(i*24+8)(ap), %rcx

	adc	eval(i*24+16)(ap), %rdx

	adc	$0, %r9

')dnl

	add	$eval(UNROLL*24), ap

	sub	$eval(UNROLL*3), %rsi

	jnc	L(top)

L(end):

	lea	L(tab)(%rip), %r8

ifdef(`PIC',

`	movslq	36(%r8,%rsi,4), %r10

	add	%r10, %r8

	jmp	*%r8

',`

	jmp	*72(%r8,%rsi,8)

')

	JUMPTABSECT

	ALIGN(8)

L(tab):	JMPENT(	L(0), L(tab))

	JMPENT(	L(1), L(tab))

	JMPENT(	L(2), L(tab))

	JMPENT(	L(3), L(tab))

	JMPENT(	L(4), L(tab))

	JMPENT(	L(5), L(tab))

	JMPENT(	L(6), L(tab))

	JMPENT(	L(7), L(tab))

	JMPENT(	L(8), L(tab))

	TEXT

L(6):	CFPROT_ENDBR

	add	(ap), %rax

	adc	8(ap), %rcx

	adc	16(ap), %rdx

	adc	$0, %r9

	add	$24, ap

L(3):	CFPROT_ENDBR

	add	(ap), %rax

	adc	8(ap), %rcx

	adc	16(ap), %rdx

	jmp	L(cj1)

L(7):	CFPROT_ENDBR

	add	(ap), %rax

	adc	8(ap), %rcx

	adc	16(ap), %rdx

	adc	$0, %r9

	add	$24, ap

L(4):	CFPROT_ENDBR

	add	(ap), %rax

	adc	8(ap), %rcx

	adc	16(ap), %rdx

	adc	$0, %r9

	add	$24, ap

L(1):	CFPROT_ENDBR

	add	(ap), %rax

	adc	$0, %rcx

	jmp	L(cj2)

L(8):	CFPROT_ENDBR

	add	(ap), %rax

	adc	8(ap), %rcx

	adc	16(ap), %rdx

	adc	$0, %r9

	add	$24, ap

L(5):	CFPROT_ENDBR

	add	(ap), %rax

	adc	8(ap), %rcx

	adc	16(ap), %rdx

	adc	$0, %r9

	add	$24, ap

L(2):	CFPROT_ENDBR

	add	(ap), %rax

	adc	8(ap), %rcx

L(cj2):	adc	$0, %rdx

L(cj1):	adc	$0, %r9

L(0):	CFPROT_ENDBR

	add	%r9, %rax

	adc	$0, %rcx

	adc	$0, %rdx

	adc	$0, %rax

	mov	%rax, %rdi		C 0mod3

	shr	$48, %rax		C 0mod3 high

	and	%r11, %rdi		C 0mod3 low

	mov	R32(%rcx), R32(%r10)	C 1mod3

	shr	$32, %rcx		C 1mod3 high

	add	%rdi, %rax		C apply 0mod3 low

	movzwl	%dx, R32(%rdi)		C 2mod3

	shl	$16, %r10		C 1mod3 low

	add	%rcx, %rax		C apply 1mod3 high

	shr	$16, %rdx		C 2mod3 high

	add	%r10, %rax		C apply 1mod3 low

	shl	$32, %rdi		C 2mod3 low

	add	%rdx, %rax		C apply 2mod3 high

	add	%rdi, %rax		C apply 2mod3 low

	FUNC_EXIT()

	ret

EPILOGUE()

CF_PROT