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! sparc __mpn_sub_n -- Subtract two limb vectors of the same length > 0 and
! store difference in a third limb vector.
! Copyright (C) 1995 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 Library General Public License as published by
! the Free Software Foundation; either version 2 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 Library General Public
! License for more details.
! You should have received a copy of the GNU Library General Public License
! along with the GNU MP Library; see the file COPYING.LIB. If not, write to
! the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
! INPUT PARAMETERS
#define res_ptr %o0
#define s1_ptr %o1
#define s2_ptr %o2
#define size %o3
#include "sysdep.h"
.text
.align 4
.global C_SYMBOL_NAME(__mpn_sub_n)
C_SYMBOL_NAME(__mpn_sub_n):
xor s2_ptr,res_ptr,%g1
andcc %g1,4,%g0
bne L1 ! branch if alignment differs
nop
! ** V1a **
andcc res_ptr,4,%g0 ! res_ptr unaligned? Side effect: cy=0
beq L_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
L_v1: addx %g0,%g0,%o4 ! save cy in register
cmp size,2 ! if size < 2 ...
bl Lend2 ! ... 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 Lfin1
subcc %g0,%o4,%g0 ! restore cy
/* Add blocks of 8 limbs until less than 8 limbs remain */
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 Loop1
subcc %g0,%o4,%g0 ! restore cy
Lfin1: addcc size,8-2,size
blt Lend1
subcc %g0,%o4,%g0 ! restore cy
/* Add blocks of 2 limbs until less than 2 limbs remain */
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 Loope1
subcc %g0,%o4,%g0 ! restore cy
Lend1: 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 Lret1
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]
Lret1: retl
addx %g0,%g0,%o0 ! return carry-out from most sign. limb
L1: xor s1_ptr,res_ptr,%g1
andcc %g1,4,%g0
bne L2
nop
! ** V1b **
andcc res_ptr,4,%g0 ! res_ptr unaligned? Side effect: cy=0
beq L_v1b ! if no, branch
nop
/* Add least significant limb separately to align res_ptr and s2_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
L_v1b: addx %g0,%g0,%o4 ! save cy in register
cmp size,2 ! if size < 2 ...
bl Lend2 ! ... 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 Lfin1b
subcc %g0,%o4,%g0 ! restore cy
/* Add blocks of 8 limbs until less than 8 limbs remain */
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 Loop1b
subcc %g0,%o4,%g0 ! restore cy
Lfin1b: addcc size,8-2,size
blt Lend1b
subcc %g0,%o4,%g0 ! restore cy
/* Add blocks of 2 limbs until less than 2 limbs remain */
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 Loope1b
subcc %g0,%o4,%g0 ! restore cy
Lend1b: 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 Lret1b
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]
Lret1b: 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. */
L2: cmp size,1
be Ljone
nop
andcc s1_ptr,4,%g0 ! s1_ptr unaligned? Side effect: cy=0
beq L_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
L_v2: addx %g0,%g0,%o4 ! save cy in register
addcc size,-8,size
blt Lfin2
subcc %g0,%o4,%g0 ! restore cy
/* Add blocks of 8 limbs until less than 8 limbs remain */
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 Loop2
subcc %g0,%o4,%g0 ! restore cy
Lfin2: addcc size,8-2,size
blt Lend2
subcc %g0,%o4,%g0 ! restore cy
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 Loope2
subcc %g0,%o4,%g0 ! restore cy
Lend2: andcc size,1,%g0
be Lret2
subcc %g0,%o4,%g0 ! restore cy
/* Add last limb */
Ljone: ld [s1_ptr],%g4
ld [s2_ptr],%g2
subxcc %g4,%g2,%o4
st %o4,[res_ptr]
Lret2: retl
addx %g0,%g0,%o0 ! return carry-out from most sign. limb
|
