! SPARC __mpn_sub_n -- Subtract two limb vectors of the same length > 0 and

! store difference in a third limb vector.

!

! Copyright (C) 1995-2018 Free Software Foundation, Inc.

!

! This file is part of the GNU MP Library.

!

! The GNU MP Library is free software; you can redistribute it and/or modify

! it under the terms of the GNU Lesser General Public License as published by

! the Free Software Foundation; either version 2.1 of the License, or (at your

! option) any later version.

!

! The GNU MP Library is distributed in the hope that it will be useful, but

! WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

! or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public

! License for more details.

!

! You should have received a copy of the GNU Lesser General Public License

! along with the GNU MP Library; see the file COPYING.LIB.  If not,

! see <http://www.gnu.org/licenses/>.

! INPUT PARAMETERS

#define RES_PTR	%o0

#define S1_PTR	%o1

#define S2_PTR	%o2

#define SIZE	%o3

#include <sysdep.h>

ENTRY(__mpn_sub_n)

	xor	S2_PTR,RES_PTR,%g1

	andcc	%g1,4,%g0

	bne	LOC(1)			! branch if alignment differs

	nop

! **  V1a  **

	andcc	RES_PTR,4,%g0		! RES_PTR unaligned? Side effect: cy=0

	be	LOC(v1)			! if no, branch

	nop

/* Add least significant limb separately to align RES_PTR and S2_PTR */

	ld	[S1_PTR],%g4

	add	S1_PTR,4,S1_PTR

	ld	[S2_PTR],%g2

	add	S2_PTR,4,S2_PTR

	add	SIZE,-1,SIZE

	subcc	%g4,%g2,%o4

	st	%o4,[RES_PTR]

	add	RES_PTR,4,RES_PTR

LOC(v1):

	addx	%g0,%g0,%o4		! save cy in register

	cmp	SIZE,2			! if SIZE < 2 ...

	bl	LOC(end2)		! ... branch to tail code

	subcc	%g0,%o4,%g0		! restore cy

	ld	[S1_PTR+0],%g4

	addcc	SIZE,-10,SIZE

	ld	[S1_PTR+4],%g1

	ldd	[S2_PTR+0],%g2

	blt	LOC(fin1)

	subcc	%g0,%o4,%g0		! restore cy

/* Add blocks of 8 limbs until less than 8 limbs remain */

LOC(loop1):

	subxcc	%g4,%g2,%o4

	ld	[S1_PTR+8],%g4

	subxcc	%g1,%g3,%o5

	ld	[S1_PTR+12],%g1

	ldd	[S2_PTR+8],%g2

	std	%o4,[RES_PTR+0]

	subxcc	%g4,%g2,%o4

	ld	[S1_PTR+16],%g4

	subxcc	%g1,%g3,%o5

	ld	[S1_PTR+20],%g1

	ldd	[S2_PTR+16],%g2

	std	%o4,[RES_PTR+8]

	subxcc	%g4,%g2,%o4

	ld	[S1_PTR+24],%g4

	subxcc	%g1,%g3,%o5

	ld	[S1_PTR+28],%g1

	ldd	[S2_PTR+24],%g2

	std	%o4,[RES_PTR+16]

	subxcc	%g4,%g2,%o4

	ld	[S1_PTR+32],%g4

	subxcc	%g1,%g3,%o5

	ld	[S1_PTR+36],%g1

	ldd	[S2_PTR+32],%g2

	std	%o4,[RES_PTR+24]

	addx	%g0,%g0,%o4		! save cy in register

	addcc	SIZE,-8,SIZE

	add	S1_PTR,32,S1_PTR

	add	S2_PTR,32,S2_PTR

	add	RES_PTR,32,RES_PTR

	bge	LOC(loop1)

	subcc	%g0,%o4,%g0		! restore cy

LOC(fin1):

	addcc	SIZE,8-2,SIZE

	blt	LOC(end1)

	subcc	%g0,%o4,%g0		! restore cy

/* Add blocks of 2 limbs until less than 2 limbs remain */

LOC(loope1):

	subxcc	%g4,%g2,%o4

	ld	[S1_PTR+8],%g4

	subxcc	%g1,%g3,%o5

	ld	[S1_PTR+12],%g1

	ldd	[S2_PTR+8],%g2

	std	%o4,[RES_PTR+0]

	addx	%g0,%g0,%o4		! save cy in register

	addcc	SIZE,-2,SIZE

	add	S1_PTR,8,S1_PTR

	add	S2_PTR,8,S2_PTR

	add	RES_PTR,8,RES_PTR

	bge	LOC(loope1)

	subcc	%g0,%o4,%g0		! restore cy

LOC(end1):

	subxcc	%g4,%g2,%o4

	subxcc	%g1,%g3,%o5

	std	%o4,[RES_PTR+0]

	addx	%g0,%g0,%o4		! save cy in register

	andcc	SIZE,1,%g0

	be	LOC(ret1)

	subcc	%g0,%o4,%g0		! restore cy

/* Add last limb */

	ld	[S1_PTR+8],%g4

	ld	[S2_PTR+8],%g2

	subxcc	%g4,%g2,%o4

	st	%o4,[RES_PTR+8]

LOC(ret1):

	retl

	addx	%g0,%g0,%o0	! return carry-out from most sign. limb

LOC(1):	xor	S1_PTR,RES_PTR,%g1

	andcc	%g1,4,%g0

	bne	LOC(2)

	nop

! **  V1b  **

	andcc	RES_PTR,4,%g0		! RES_PTR unaligned? Side effect: cy=0

	be	LOC(v1b)		! if no, branch

	nop

/* Add least significant limb separately to align RES_PTR and S1_PTR */

	ld	[S2_PTR],%g4

	add	S2_PTR,4,S2_PTR

	ld	[S1_PTR],%g2

	add	S1_PTR,4,S1_PTR

	add	SIZE,-1,SIZE

	subcc	%g2,%g4,%o4

	st	%o4,[RES_PTR]

	add	RES_PTR,4,RES_PTR

LOC(v1b):

	addx	%g0,%g0,%o4		! save cy in register

	cmp	SIZE,2			! if SIZE < 2 ...

	bl	LOC(end2)		! ... branch to tail code

	subcc	%g0,%o4,%g0		! restore cy

	ld	[S2_PTR+0],%g4

	addcc	SIZE,-10,SIZE

	ld	[S2_PTR+4],%g1

	ldd	[S1_PTR+0],%g2

	blt	LOC(fin1b)

	subcc	%g0,%o4,%g0		! restore cy

/* Add blocks of 8 limbs until less than 8 limbs remain */

LOC(loop1b):

	subxcc	%g2,%g4,%o4

	ld	[S2_PTR+8],%g4

	subxcc	%g3,%g1,%o5

	ld	[S2_PTR+12],%g1

	ldd	[S1_PTR+8],%g2

	std	%o4,[RES_PTR+0]

	subxcc	%g2,%g4,%o4

	ld	[S2_PTR+16],%g4

	subxcc	%g3,%g1,%o5

	ld	[S2_PTR+20],%g1

	ldd	[S1_PTR+16],%g2

	std	%o4,[RES_PTR+8]

	subxcc	%g2,%g4,%o4

	ld	[S2_PTR+24],%g4

	subxcc	%g3,%g1,%o5

	ld	[S2_PTR+28],%g1

	ldd	[S1_PTR+24],%g2

	std	%o4,[RES_PTR+16]

	subxcc	%g2,%g4,%o4

	ld	[S2_PTR+32],%g4

	subxcc	%g3,%g1,%o5

	ld	[S2_PTR+36],%g1

	ldd	[S1_PTR+32],%g2

	std	%o4,[RES_PTR+24]

	addx	%g0,%g0,%o4		! save cy in register

	addcc	SIZE,-8,SIZE

	add	S1_PTR,32,S1_PTR

	add	S2_PTR,32,S2_PTR

	add	RES_PTR,32,RES_PTR

	bge	LOC(loop1b)

	subcc	%g0,%o4,%g0		! restore cy

LOC(fin1b):

	addcc	SIZE,8-2,SIZE

	blt	LOC(end1b)

	subcc	%g0,%o4,%g0		! restore cy

/* Add blocks of 2 limbs until less than 2 limbs remain */

LOC(loope1b):

	subxcc	%g2,%g4,%o4

	ld	[S2_PTR+8],%g4

	subxcc	%g3,%g1,%o5

	ld	[S2_PTR+12],%g1

	ldd	[S1_PTR+8],%g2

	std	%o4,[RES_PTR+0]

	addx	%g0,%g0,%o4		! save cy in register

	addcc	SIZE,-2,SIZE

	add	S1_PTR,8,S1_PTR

	add	S2_PTR,8,S2_PTR

	add	RES_PTR,8,RES_PTR

	bge	LOC(loope1b)

	subcc	%g0,%o4,%g0		! restore cy

LOC(end1b):

	subxcc	%g2,%g4,%o4

	subxcc	%g3,%g1,%o5

	std	%o4,[RES_PTR+0]

	addx	%g0,%g0,%o4		! save cy in register

	andcc	SIZE,1,%g0

	be	LOC(ret1b)

	subcc	%g0,%o4,%g0		! restore cy

/* Add last limb */

	ld	[S2_PTR+8],%g4

	ld	[S1_PTR+8],%g2

	subxcc	%g2,%g4,%o4

	st	%o4,[RES_PTR+8]

LOC(ret1b):

	retl

	addx	%g0,%g0,%o0	! return carry-out from most sign. limb

! **  V2  **

/* If we come here, the alignment of S1_PTR and RES_PTR as well as the

   alignment of S2_PTR and RES_PTR differ.  Since there are only two ways

   things can be aligned (that we care about) we now know that the alignment

   of S1_PTR and S2_PTR are the same.  */

LOC(2):	cmp	SIZE,1

	be	LOC(jone)

	nop

	andcc	S1_PTR,4,%g0		! S1_PTR unaligned? Side effect: cy=0

	be	LOC(v2)			! if no, branch

	nop

/* Add least significant limb separately to align S1_PTR and S2_PTR */

	ld	[S1_PTR],%g4

	add	S1_PTR,4,S1_PTR

	ld	[S2_PTR],%g2

	add	S2_PTR,4,S2_PTR

	add	SIZE,-1,SIZE

	subcc	%g4,%g2,%o4

	st	%o4,[RES_PTR]

	add	RES_PTR,4,RES_PTR

LOC(v2):

	addx	%g0,%g0,%o4		! save cy in register

	addcc	SIZE,-8,SIZE

	blt	LOC(fin2)

	subcc	%g0,%o4,%g0		! restore cy

/* Add blocks of 8 limbs until less than 8 limbs remain */

LOC(loop2):

	ldd	[S1_PTR+0],%g2

	ldd	[S2_PTR+0],%o4

	subxcc	%g2,%o4,%g2

	st	%g2,[RES_PTR+0]

	subxcc	%g3,%o5,%g3

	st	%g3,[RES_PTR+4]

	ldd	[S1_PTR+8],%g2

	ldd	[S2_PTR+8],%o4

	subxcc	%g2,%o4,%g2

	st	%g2,[RES_PTR+8]

	subxcc	%g3,%o5,%g3

	st	%g3,[RES_PTR+12]

	ldd	[S1_PTR+16],%g2

	ldd	[S2_PTR+16],%o4

	subxcc	%g2,%o4,%g2

	st	%g2,[RES_PTR+16]

	subxcc	%g3,%o5,%g3

	st	%g3,[RES_PTR+20]

	ldd	[S1_PTR+24],%g2

	ldd	[S2_PTR+24],%o4

	subxcc	%g2,%o4,%g2

	st	%g2,[RES_PTR+24]

	subxcc	%g3,%o5,%g3

	st	%g3,[RES_PTR+28]

	addx	%g0,%g0,%o4		! save cy in register

	addcc	SIZE,-8,SIZE

	add	S1_PTR,32,S1_PTR

	add	S2_PTR,32,S2_PTR

	add	RES_PTR,32,RES_PTR

	bge	LOC(loop2)

	subcc	%g0,%o4,%g0		! restore cy

LOC(fin2):

	addcc	SIZE,8-2,SIZE

	blt	LOC(end2)

	subcc	%g0,%o4,%g0		! restore cy

LOC(loope2):

	ldd	[S1_PTR+0],%g2

	ldd	[S2_PTR+0],%o4

	subxcc	%g2,%o4,%g2

	st	%g2,[RES_PTR+0]

	subxcc	%g3,%o5,%g3

	st	%g3,[RES_PTR+4]

	addx	%g0,%g0,%o4		! save cy in register

	addcc	SIZE,-2,SIZE

	add	S1_PTR,8,S1_PTR

	add	S2_PTR,8,S2_PTR

	add	RES_PTR,8,RES_PTR

	bge	LOC(loope2)

	subcc	%g0,%o4,%g0		! restore cy

LOC(end2):

	andcc	SIZE,1,%g0

	be	LOC(ret2)

	subcc	%g0,%o4,%g0		! restore cy

/* Add last limb */

LOC(jone):

	ld	[S1_PTR],%g4

	ld	[S2_PTR],%g2

	subxcc	%g4,%g2,%o4

	st	%o4,[RES_PTR]

LOC(ret2):

	retl

	addx	%g0,%g0,%o0	! return carry-out from most sign. limb

END(__mpn_sub_n)