| # Alpha __mpn_sub_n -- Subtract two limb vectors of the same length > 0 and |
| # store difference in a third limb vector. |
| |
| # Copyright (C) 1995-2014 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. If not, see <http://www.gnu.org/licenses/>. |
| |
| |
| # INPUT PARAMETERS |
| # res_ptr $16 |
| # s1_ptr $17 |
| # s2_ptr $18 |
| # size $19 |
| |
| .set noreorder |
| .set noat |
| .text |
| .align 3 |
| .globl __mpn_sub_n |
| .ent __mpn_sub_n |
| __mpn_sub_n: |
| .frame $30,0,$26,0 |
| |
| or $31,$31,$25 # clear cy |
| subq $19,4,$19 # decr loop cnt |
| blt $19,.Lend2 # if less than 4 limbs, goto 2nd loop |
| # Start software pipeline for 1st loop |
| ldq $0,0($18) |
| ldq $1,8($18) |
| ldq $4,0($17) |
| ldq $5,8($17) |
| addq $17,32,$17 # update s1_ptr |
| ldq $2,16($18) |
| subq $4,$0,$20 # 1st main sub |
| ldq $3,24($18) |
| subq $19,4,$19 # decr loop cnt |
| ldq $6,-16($17) |
| cmpult $4,$20,$25 # compute cy from last sub |
| ldq $7,-8($17) |
| addq $1,$25,$28 # cy add |
| addq $18,32,$18 # update s2_ptr |
| subq $5,$28,$21 # 2nd main sub |
| cmpult $28,$25,$8 # compute cy from last add |
| blt $19,.Lend1 # if less than 4 limbs remain, jump |
| # 1st loop handles groups of 4 limbs in a software pipeline |
| .align 4 |
| .Loop: cmpult $5,$21,$25 # compute cy from last add |
| ldq $0,0($18) |
| or $8,$25,$25 # combine cy from the two adds |
| ldq $1,8($18) |
| addq $2,$25,$28 # cy add |
| ldq $4,0($17) |
| subq $6,$28,$22 # 3rd main sub |
| ldq $5,8($17) |
| cmpult $28,$25,$8 # compute cy from last add |
| cmpult $6,$22,$25 # compute cy from last add |
| stq $20,0($16) |
| or $8,$25,$25 # combine cy from the two adds |
| stq $21,8($16) |
| addq $3,$25,$28 # cy add |
| subq $7,$28,$23 # 4th main sub |
| cmpult $28,$25,$8 # compute cy from last add |
| cmpult $7,$23,$25 # compute cy from last add |
| addq $17,32,$17 # update s1_ptr |
| or $8,$25,$25 # combine cy from the two adds |
| addq $16,32,$16 # update res_ptr |
| addq $0,$25,$28 # cy add |
| ldq $2,16($18) |
| subq $4,$28,$20 # 1st main sub |
| ldq $3,24($18) |
| cmpult $28,$25,$8 # compute cy from last add |
| ldq $6,-16($17) |
| cmpult $4,$20,$25 # compute cy from last add |
| ldq $7,-8($17) |
| or $8,$25,$25 # combine cy from the two adds |
| subq $19,4,$19 # decr loop cnt |
| stq $22,-16($16) |
| addq $1,$25,$28 # cy add |
| stq $23,-8($16) |
| subq $5,$28,$21 # 2nd main sub |
| addq $18,32,$18 # update s2_ptr |
| cmpult $28,$25,$8 # compute cy from last add |
| bge $19,.Loop |
| # Finish software pipeline for 1st loop |
| .Lend1: cmpult $5,$21,$25 # compute cy from last add |
| or $8,$25,$25 # combine cy from the two adds |
| addq $2,$25,$28 # cy add |
| subq $6,$28,$22 # 3rd main sub |
| cmpult $28,$25,$8 # compute cy from last add |
| cmpult $6,$22,$25 # compute cy from last add |
| stq $20,0($16) |
| or $8,$25,$25 # combine cy from the two adds |
| stq $21,8($16) |
| addq $3,$25,$28 # cy add |
| subq $7,$28,$23 # 4th main sub |
| cmpult $28,$25,$8 # compute cy from last add |
| cmpult $7,$23,$25 # compute cy from last add |
| or $8,$25,$25 # combine cy from the two adds |
| addq $16,32,$16 # update res_ptr |
| stq $22,-16($16) |
| stq $23,-8($16) |
| .Lend2: addq $19,4,$19 # restore loop cnt |
| beq $19,.Lret |
| # Start software pipeline for 2nd loop |
| ldq $0,0($18) |
| ldq $4,0($17) |
| subq $19,1,$19 |
| beq $19,.Lend0 |
| # 2nd loop handles remaining 1-3 limbs |
| .align 4 |
| .Loop0: addq $0,$25,$28 # cy add |
| ldq $0,8($18) |
| subq $4,$28,$20 # main sub |
| ldq $1,8($17) |
| addq $18,8,$18 |
| cmpult $28,$25,$8 # compute cy from last add |
| addq $17,8,$17 |
| stq $20,0($16) |
| cmpult $4,$20,$25 # compute cy from last add |
| subq $19,1,$19 # decr loop cnt |
| or $8,$25,$25 # combine cy from the two adds |
| addq $16,8,$16 |
| or $1,$31,$4 |
| bne $19,.Loop0 |
| .Lend0: addq $0,$25,$28 # cy add |
| subq $4,$28,$20 # main sub |
| cmpult $28,$25,$8 # compute cy from last add |
| cmpult $4,$20,$25 # compute cy from last add |
| stq $20,0($16) |
| or $8,$25,$25 # combine cy from the two adds |
| |
| .Lret: or $25,$31,$0 # return cy |
| ret $31,($26),1 |
| .end __mpn_sub_n |
