| dnl ARM/Thumb mpn_sub_n. |
| |
| dnl Copyright 1997, 2000, 2012 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 |
| dnl The GNU MP Library is distributed in the hope that it will be useful, but |
| dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| dnl for more details. |
| dnl |
| dnl You should have received copies of the GNU General Public License and the |
| dnl GNU Lesser General Public License along with the GNU MP Library. If not, |
| dnl see https://www.gnu.org/licenses/. |
| |
| include(`../config.m4') |
| |
| C INPUT PARAMETERS |
| define(`rp', r0) |
| define(`up', r1) |
| define(`vp', r2) |
| define(`n', r3) |
| |
| ASM_START() |
| .thumb |
| PROLOGUE(mpn_sub_nc) |
| push {r4, r5, r6} |
| ldr r6, [sp, #12] C init carry save register |
| neg r6, r6 |
| b L(top) |
| EPILOGUE() |
| PROLOGUE(mpn_sub_n) |
| push {r4, r5, r6} |
| mov r6, n C init carry save register |
| |
| L(top): ldmia up!, {r4} C load next limb from S1 |
| cmp n, r6 C tricky carry restore |
| ldmia vp!, {r5} C load next limb from S2 |
| sbc r4, r5 |
| stmia rp!, {r4} C store result limb to RES |
| sbc r6, r6 C save negated carry |
| sub n, #1 |
| bne L(top) |
| |
| neg r0, r6 |
| pop {r4, r5, r6} |
| bx lr |
| EPILOGUE() |
