dnl  AMD64 mpn_rshift -- mpn right shift.

dnl  Copyright 2003, 2005, 2009, 2011, 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	 2.375

C AMD K10	 2.375

C Intel P4	 8

C Intel core2	 2.11

C Intel corei	 ?

C Intel atom	 5.75

C VIA nano	 3.5

C INPUT PARAMETERS

define(`rp',	`%rdi')

define(`up',	`%rsi')

define(`n',	`%rdx')

define(`cnt',	`%rcx')

ABI_SUPPORT(DOS64)

ABI_SUPPORT(STD64)

ASM_START()

	TEXT

	ALIGN(32)

PROLOGUE(mpn_rshift)

	FUNC_ENTRY(4)

	neg	R32(%rcx)		C put rsh count in cl

	mov	(up), %rax

	shl	R8(%rcx), %rax		C function return value

	neg	R32(%rcx)		C put lsh count in cl

	lea	1(n), R32(%r8)

	lea	-8(up,n,8), up

	lea	-8(rp,n,8), rp

	neg	n

	and	$3, R32(%r8)

	je	L(rlx)			C jump for n = 3, 7, 11, ...

	dec	R32(%r8)

	jne	L(1)

C	n = 4, 8, 12, ...

	mov	8(up,n,8), %r10

	shr	R8(%rcx), %r10

	neg	R32(%rcx)		C put rsh count in cl

	mov	16(up,n,8), %r8

	shl	R8(%rcx), %r8

	or	%r8, %r10

	mov	%r10, 8(rp,n,8)

	inc	n

	jmp	L(rll)

L(1):	dec	R32(%r8)

	je	L(1x)			C jump for n = 1, 5, 9, 13, ...

C	n = 2, 6, 10, 16, ...

	mov	8(up,n,8), %r10

	shr	R8(%rcx), %r10

	neg	R32(%rcx)		C put rsh count in cl

	mov	16(up,n,8), %r8

	shl	R8(%rcx), %r8

	or	%r8, %r10

	mov	%r10, 8(rp,n,8)

	inc	n

	neg	R32(%rcx)		C put lsh count in cl

L(1x):

	cmp	$-1, n

	je	L(ast)

	mov	8(up,n,8), %r10

	shr	R8(%rcx), %r10

	mov	16(up,n,8), %r11

	shr	R8(%rcx), %r11

	neg	R32(%rcx)		C put rsh count in cl

	mov	16(up,n,8), %r8

	mov	24(up,n,8), %r9

	shl	R8(%rcx), %r8

	or	%r8, %r10

	shl	R8(%rcx), %r9

	or	%r9, %r11

	mov	%r10, 8(rp,n,8)

	mov	%r11, 16(rp,n,8)

	add	$2, n

L(rll):	neg	R32(%rcx)		C put lsh count in cl

L(rlx):	mov	8(up,n,8), %r10

	shr	R8(%rcx), %r10

	mov	16(up,n,8), %r11

	shr	R8(%rcx), %r11

	add	$4, n			C				      4

	jb	L(end)			C				      2

	ALIGN(16)

L(top):

	C finish stuff from lsh block

	neg	R32(%rcx)		C put rsh count in cl

	mov	-16(up,n,8), %r8

	mov	-8(up,n,8), %r9

	shl	R8(%rcx), %r8

	or	%r8, %r10

	shl	R8(%rcx), %r9

	or	%r9, %r11

	mov	%r10, -24(rp,n,8)

	mov	%r11, -16(rp,n,8)

	C start two new rsh

	mov	(up,n,8), %r8

	mov	8(up,n,8), %r9

	shl	R8(%rcx), %r8

	shl	R8(%rcx), %r9

	C finish stuff from rsh block

	neg	R32(%rcx)		C put lsh count in cl

	mov	-8(up,n,8), %r10

	mov	0(up,n,8), %r11

	shr	R8(%rcx), %r10

	or	%r10, %r8

	shr	R8(%rcx), %r11

	or	%r11, %r9

	mov	%r8, -8(rp,n,8)

	mov	%r9, 0(rp,n,8)

	C start two new lsh

	mov	8(up,n,8), %r10

	mov	16(up,n,8), %r11

	shr	R8(%rcx), %r10

	shr	R8(%rcx), %r11

	add	$4, n

	jae	L(top)			C				      2

L(end):

	neg	R32(%rcx)		C put rsh count in cl

	mov	-8(up), %r8

	shl	R8(%rcx), %r8

	or	%r8, %r10

	mov	(up), %r9

	shl	R8(%rcx), %r9

	or	%r9, %r11

	mov	%r10, -16(rp)

	mov	%r11, -8(rp)

	neg	R32(%rcx)		C put lsh count in cl

L(ast):	mov	(up), %r10

	shr	R8(%rcx), %r10

	mov	%r10, (rp)

	FUNC_EXIT()

	ret

EPILOGUE()