dnl  Alpha mpn_addlsh1_n/mpn_sublsh1_n -- rp[] = up[] +- (vp[] << 1).

dnl  Copyright 2003, 2013 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
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dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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dnl  You should have received copies of the GNU General Public License and the
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dnl  see https://www.gnu.org/licenses/.

include(`../config.m4')

C      cycles/limb
C EV4:     ?
C EV5:     7
C EV6:     4

C TODO
C  * Tune to reach 3.75 c/l on ev6.

define(`rp',`r16')
define(`up',`r17')
define(`vp',`r18')
define(`n', `r19')

define(`u0', `r8')
define(`u1', `r1')
define(`v0', `r4')
define(`v1', `r5')

define(`cy0', `r0')
define(`cy1', `r20')
define(`cy', `r22')
define(`rr', `r24')
define(`ps', `r25')
define(`sl', `r28')

ifdef(`OPERATION_addlsh1_n',`
  define(ADDSUB,       addq)
  define(CARRY,       `cmpult $1,$2,$3')
  define(func, mpn_addlsh1_n)
')
ifdef(`OPERATION_sublsh1_n',`
  define(ADDSUB,       subq)
  define(CARRY,       `cmpult $2,$1,$3')
  define(func, mpn_sublsh1_n)
')

MULFUNC_PROLOGUE(mpn_addlsh1_n mpn_sublsh1_n)

ASM_START()
PROLOGUE(func)
	and	n, 2, cy0
	blbs	n, L(bx1)
L(bx0):	ldq	v1, 0(vp)
	ldq	u1, 0(up)
	lda	r2, 0(r31)
	bne	cy0, L(b10)

L(b00):	lda	vp, 48(vp)
	lda	up, -16(up)
	lda	rp, -8(rp)
	lda	cy0, 0(r31)
	br	r31, L(lo0)

L(b10):	lda	vp, 32(vp)
	lda	rp, 8(rp)
	lda	cy0, 0(r31)
	br	r31, L(lo2)

L(bx1):	ldq	v0, 0(vp)
	ldq	u0, 0(up)
	lda	r3, 0(r31)
	beq	cy0, L(b01)

L(b11):	lda	vp, 40(vp)
	lda	up, -24(up)
	lda	rp, 16(rp)
	lda	cy1, 0(r31)
	br	r31, L(lo3)

L(b01):	lda	n, -4(n)
	lda	cy1, 0(r31)
	ble	n, L(end)
	lda	vp, 24(vp)
	lda	up, -8(up)

	ALIGN(16)
L(top):	addq	v0, v0, r6
	ldq	v1, -16(vp)
	addq	r6, r3, sl	C combined vlimb
	ldq	u1, 16(up)
	ADDSUB	u0, sl, ps	C ulimb + (vlimb << 1)
	cmplt	v0, r31, r2	C high v bits
	ADDSUB	ps, cy1, rr	C consume carry from previous operation
	CARRY(	ps, u0, cy0)	C carry out #2
	stq	rr, 0(rp)
	CARRY(	rr, ps, cy)	C carry out #3
	lda	vp, 32(vp)	C bookkeeping
	addq	cy, cy0, cy0	C final carry out
L(lo0):	addq	v1, v1, r7
	ldq	v0, -40(vp)
	addq	r7, r2, sl
	ldq	u0, 24(up)
	ADDSUB	u1, sl, ps
	cmplt	v1, r31, r3
	ADDSUB	ps, cy0, rr
	CARRY(	ps, u1, cy1)
	stq	rr, 8(rp)
	CARRY(	rr, ps, cy)
	lda	rp, 32(rp)	C bookkeeping
	addq	cy, cy1, cy1
L(lo3):	addq	v0, v0, r6
	ldq	v1, -32(vp)
	addq	r6, r3, sl
	ldq	u1, 32(up)
	ADDSUB	u0, sl, ps
	cmplt	v0, r31, r2
	ADDSUB	ps, cy1, rr
	CARRY(	ps, u0, cy0)
	stq	rr, -16(rp)
	CARRY(	rr, ps, cy)
	lda	up, 32(up)	C bookkeeping
	addq	cy, cy0, cy0
L(lo2):	addq	v1, v1, r7
	ldq	v0, -24(vp)
	addq	r7, r2, sl
	ldq	u0, 8(up)
	ADDSUB	u1, sl, ps
	cmplt	v1, r31, r3
	ADDSUB	ps, cy0, rr
	CARRY(	ps, u1, cy1)
	stq	rr, -8(rp)
	CARRY(	rr, ps, cy)
	lda	n, -4(n)	C bookkeeping
	addq	cy, cy1, cy1
	bgt	n, L(top)

L(end):	addq	v0, v0, r6
	addq	r6, r3, sl
	ADDSUB	u0, sl, ps
	cmplt	v0, r31, r2
	ADDSUB	ps, cy1, rr
	CARRY(	ps, u0, cy0)
	stq	rr, 0(rp)
	CARRY(	rr, ps, cy)
	addq	cy, cy0, cy0
	addq	cy0, r2, r0

	ret	r31,(r26),1
EPILOGUE()
ASM_END()