dnl  Alpha mpn_submul_1 -- Multiply a limb vector with a limb and subtract

dnl  the result from a second limb vector.

dnl  Copyright 1992, 1994, 1995, 2000, 2002 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 EV4:     42

C EV5:     18

C EV6:      7

C  INPUT PARAMETERS

C  rp	r16

C  up	r17

C  n	r18

C  limb	r19

ASM_START()

PROLOGUE(mpn_submul_1)

	ldq	r2,0(r17)	C r2 = s1_limb

	addq	r17,8,r17	C s1_ptr++

	subq	r18,1,r18	C size--

	mulq	r2,r19,r3	C r3 = prod_low

	ldq	r5,0(r16)	C r5 = *res_ptr

	umulh	r2,r19,r0	C r0 = prod_high

	beq	r18,$Lend1	C jump if size was == 1

	ldq	r2,0(r17)	C r2 = s1_limb

	addq	r17,8,r17	C s1_ptr++

	subq	r18,1,r18	C size--

	subq	r5,r3,r3

	cmpult	r5,r3,r4

	stq	r3,0(r16)

	addq	r16,8,r16	C res_ptr++

	beq	r18,$Lend2	C jump if size was == 2

	ALIGN(8)

$Loop:	mulq	r2,r19,r3	C r3 = prod_low

	ldq	r5,0(r16)	C r5 = *res_ptr

	addq	r4,r0,r0	C cy_limb = cy_limb + 'cy'

	subq	r18,1,r18	C size--

	umulh	r2,r19,r4	C r4 = cy_limb

	ldq	r2,0(r17)	C r2 = s1_limb

	addq	r17,8,r17	C s1_ptr++

	addq	r3,r0,r3	C r3 = cy_limb + prod_low

	cmpult	r3,r0,r0	C r0 = carry from (cy_limb + prod_low)

	subq	r5,r3,r3

	cmpult	r5,r3,r5

	stq	r3,0(r16)

	addq	r16,8,r16	C res_ptr++

	addq	r5,r0,r0	C combine carries

	bne	r18,$Loop

$Lend2:	mulq	r2,r19,r3	C r3 = prod_low

	ldq	r5,0(r16)	C r5 = *res_ptr

	addq	r4,r0,r0	C cy_limb = cy_limb + 'cy'

	umulh	r2,r19,r4	C r4 = cy_limb

	addq	r3,r0,r3	C r3 = cy_limb + prod_low

	cmpult	r3,r0,r0	C r0 = carry from (cy_limb + prod_low)

	subq	r5,r3,r3

	cmpult	r5,r3,r5

	stq	r3,0(r16)

	addq	r5,r0,r0	C combine carries

	addq	r4,r0,r0	C cy_limb = prod_high + cy

	ret	r31,(r26),1

$Lend1:	subq	r5,r3,r3

	cmpult	r5,r3,r5

	stq	r3,0(r16)

	addq	r0,r5,r0

	ret	r31,(r26),1

EPILOGUE(mpn_submul_1)

ASM_END()