dnl  AMD64 mpn_sublsh1_n -- rp[] = up[] - (vp[] << 1)

dnl  Copyright 2003, 2005-2007, 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	 2.2

C AMD K10	 2.2

C Intel P4	12.75

C Intel core2	 3.45

C Intel corei	 ?

C Intel atom	 ?

C VIA nano	 3.25

C Sometimes speed degenerates, supposedly related to that some operand

C alignments cause cache conflicts.

C The speed is limited by decoding/issue bandwidth.  There are 26 instructions

C in the loop, which corresponds to 26/3/4 = 2.167 c/l.

C INPUT PARAMETERS

define(`rp',`%rdi')

define(`up',`%rsi')

define(`vp',`%rdx')

define(`n', `%rcx')

ABI_SUPPORT(DOS64)

ABI_SUPPORT(STD64)

ASM_START()

	TEXT

	ALIGN(16)

PROLOGUE(mpn_sublsh1_n)

	FUNC_ENTRY(4)

	push	%rbx

	push	%rbp

	mov	(vp), %r8

	mov	R32(n), R32(%rax)

	lea	(rp,n,8), rp

	lea	(up,n,8), up

	lea	(vp,n,8), vp

	neg	n

	xor	R32(%rbp), R32(%rbp)

	and	$3, R32(%rax)

	je	L(b00)

	cmp	$2, R32(%rax)

	jc	L(b01)

	je	L(b10)

L(b11):	add	%r8, %r8

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

	adc	%r9, %r9

	mov	16(vp,n,8), %r10

	adc	%r10, %r10

	sbb	R32(%rax), R32(%rax)	C save scy

	mov	(up,n,8), %rbp

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

	sub	%r8, %rbp

	sbb	%r9, %rbx

	mov	%rbp, (rp,n,8)

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

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

	sbb	%r10, %rbp

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

	sbb	R32(%rbp), R32(%rbp)	C save acy

	add	$3, n

	jmp	L(ent)

L(b10):	add	%r8, %r8

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

	adc	%r9, %r9

	sbb	R32(%rax), R32(%rax)	C save scy

	mov	(up,n,8), %rbp

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

	sub	%r8, %rbp

	sbb	%r9, %rbx

	mov	%rbp, (rp,n,8)

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

	sbb	R32(%rbp), R32(%rbp)	C save acy

	add	$2, n

	jmp	L(ent)

L(b01):	add	%r8, %r8

	sbb	R32(%rax), R32(%rax)	C save scy

	mov	(up,n,8), %rbp

	sub	%r8, %rbp

	mov	%rbp, (rp,n,8)

	sbb	R32(%rbp), R32(%rbp)	C save acy

	inc	n

L(ent):	jns	L(end)

	ALIGN(16)

L(top):	add	R32(%rax), R32(%rax)	C restore scy

	mov	(vp,n,8), %r8

L(b00):	adc	%r8, %r8

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

	adc	%r9, %r9

	mov	16(vp,n,8), %r10

	adc	%r10, %r10

	mov	24(vp,n,8), %r11

	adc	%r11, %r11

	sbb	R32(%rax), R32(%rax)	C save scy

	add	R32(%rbp), R32(%rbp)	C restore acy

	mov	(up,n,8), %rbp

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

	sbb	%r8, %rbp

	sbb	%r9, %rbx

	mov	%rbp, (rp,n,8)

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

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

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

	sbb	%r10, %rbp

	sbb	%r11, %rbx

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

	mov	%rbx, 24(rp,n,8)

	sbb	R32(%rbp), R32(%rbp)	C save acy

	add	$4, n

	js	L(top)

L(end):	add	R32(%rbp), R32(%rax)

	neg	R32(%rax)

	pop	%rbp

	pop	%rbx

	FUNC_EXIT()

	ret

EPILOGUE()

CF_PROT