| dnl IBM POWER mpn_mul_1 -- Multiply a limb vector with a limb and store the |
| dnl result in a second limb vector. |
| |
| dnl Copyright 1992, 1994, 1999-2001 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/. |
| |
| |
| dnl INPUT PARAMETERS |
| dnl res_ptr r3 |
| dnl s1_ptr r4 |
| dnl size r5 |
| dnl s2_limb r6 |
| |
| dnl The POWER architecture has no unsigned 32x32->64 bit multiplication |
| dnl instruction. To obtain that operation, we have to use the 32x32->64 |
| dnl signed multiplication instruction, and add the appropriate compensation to |
| dnl the high limb of the result. We add the multiplicand if the multiplier |
| dnl has its most significant bit set, and we add the multiplier if the |
| dnl multiplicand has its most significant bit set. We need to preserve the |
| dnl carry flag between each iteration, so we have to compute the compensation |
| dnl carefully (the natural, srai+and doesn't work). Since all POWER can |
| dnl branch in zero cycles, we use conditional branches for the compensation. |
| |
| include(`../config.m4') |
| |
| ASM_START() |
| PROLOGUE(mpn_mul_1) |
| cal 3,-4(3) |
| l 0,0(4) |
| cmpi 0,6,0 |
| mtctr 5 |
| mul 9,0,6 |
| srai 7,0,31 |
| and 7,7,6 |
| mfmq 8 |
| ai 0,0,0 C reset carry |
| cax 9,9,7 |
| blt Lneg |
| Lpos: bdz Lend |
| Lploop: lu 0,4(4) |
| stu 8,4(3) |
| cmpi 0,0,0 |
| mul 10,0,6 |
| mfmq 0 |
| ae 8,0,9 |
| bge Lp0 |
| cax 10,10,6 C adjust high limb for negative limb from s1 |
| Lp0: bdz Lend0 |
| lu 0,4(4) |
| stu 8,4(3) |
| cmpi 0,0,0 |
| mul 9,0,6 |
| mfmq 0 |
| ae 8,0,10 |
| bge Lp1 |
| cax 9,9,6 C adjust high limb for negative limb from s1 |
| Lp1: bdn Lploop |
| b Lend |
| |
| Lneg: cax 9,9,0 |
| bdz Lend |
| Lnloop: lu 0,4(4) |
| stu 8,4(3) |
| cmpi 0,0,0 |
| mul 10,0,6 |
| cax 10,10,0 C adjust high limb for negative s2_limb |
| mfmq 0 |
| ae 8,0,9 |
| bge Ln0 |
| cax 10,10,6 C adjust high limb for negative limb from s1 |
| Ln0: bdz Lend0 |
| lu 0,4(4) |
| stu 8,4(3) |
| cmpi 0,0,0 |
| mul 9,0,6 |
| cax 9,9,0 C adjust high limb for negative s2_limb |
| mfmq 0 |
| ae 8,0,10 |
| bge Ln1 |
| cax 9,9,6 C adjust high limb for negative limb from s1 |
| Ln1: bdn Lnloop |
| b Lend |
| |
| Lend0: cal 9,0(10) |
| Lend: st 8,4(3) |
| aze 3,9 |
| br |
| EPILOGUE(mpn_mul_1) |
