| @ ARM/Thumb mpn_sub_n -- Subtract two limb vectors of the same length > 0 and |
| @ store difference in a third limb vector. |
| |
| @ Copyright 1997, 2000 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 3 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 r0 |
| @ S1_ptr r1 |
| @ S2_ptr r2 |
| @ SIZE r3 |
| |
| @ NOT TESTED CODE |
| |
| .text |
| .thumb |
| .align 0 |
| .global ___gmpn_sub_n |
| ___gmpn_sub_n: |
| push {r4, r5, r6, lr} |
| mov r6, #1 @ init carry save register |
| |
| Loop: sub r6, #1 @ restore carry (set iff r6 was 0) |
| ldmia r1!, {r4} @ load next limb from S1 |
| ldmia r2!, {r5} @ load next limb from S2 |
| sbc r4, r5 |
| stmia r0!, {r4} @ store result limb to RES |
| sbc r6, r6 @ save negated carry |
| sub r3, #1 |
| bge Loop @ loop back while remaining count >= 4 |
| |
| mov r0, r6 |
| pop {r4, r5, r6, pc} |