| dnl ARM64 mpn_bdiv_q_1, mpn_pi1_bdiv_q_1 -- Hensel division by 1-limb divisor. |
| |
| dnl Contributed to the GNU project by Torbjรถrn Granlund. |
| |
| dnl Copyright 2012, 2017 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 cycles/limb |
| C norm unorm |
| C Cortex-A53 12 15 |
| C Cortex-A57 12 12 |
| C Cortex-A72 |
| C Cortex-A73 |
| C X-Gene 11 11 |
| |
| C TODO |
| C * Scheduling of umulh later in the unorm loop brings A53 time to 12 c/l. |
| C Unfortunately, that requires software pipelining. |
| |
| define(`rp', `x0') |
| define(`up', `x1') |
| define(`n', `x2') |
| define(`d', `x3') |
| define(`di', `x4') C just mpn_pi1_bdiv_q_1 |
| define(`cnt', `x5') C just mpn_pi1_bdiv_q_1 |
| |
| define(`cy', `r7') |
| define(`tnc', `x8') |
| |
| ASM_START() |
| PROLOGUE(mpn_bdiv_q_1) |
| |
| rbit x6, d |
| clz cnt, x6 |
| lsr d, d, cnt |
| |
| LEA_HI( x7, binvert_limb_table) |
| ubfx x6, d, 1, 7 |
| LEA_LO( x7, binvert_limb_table) |
| ldrb w6, [x7, x6] |
| ubfiz x7, x6, 1, 8 |
| umull x6, w6, w6 |
| msub x6, x6, d, x7 |
| lsl x7, x6, 1 |
| mul x6, x6, x6 |
| msub x6, x6, d, x7 |
| lsl x7, x6, 1 |
| mul x6, x6, x6 |
| msub di, x6, d, x7 |
| |
| b GSYM_PREFIX`'mpn_pi1_bdiv_q_1 |
| EPILOGUE() |
| |
| PROLOGUE(mpn_pi1_bdiv_q_1) |
| sub n, n, #1 |
| subs x6, x6, x6 C clear r6 and C flag |
| ldr x9, [up],#8 |
| cbz cnt, L(norm) |
| |
| L(unorm): |
| lsr x12, x9, cnt |
| cbz n, L(eu1) |
| sub tnc, xzr, cnt |
| |
| L(tpu): ldr x9, [up],#8 |
| lsl x7, x9, tnc |
| orr x7, x7, x12 |
| sbcs x6, x7, x6 |
| mul x7, x6, di |
| str x7, [rp],#8 |
| lsr x12, x9, cnt |
| umulh x6, x7, d |
| sub n, n, #1 |
| cbnz n, L(tpu) |
| |
| L(eu1): sbcs x6, x12, x6 |
| mul x6, x6, di |
| str x6, [rp] |
| ret |
| |
| L(norm): |
| mul x5, x9, di |
| str x5, [rp],#8 |
| cbz n, L(en1) |
| |
| L(tpn): ldr x9, [up],#8 |
| umulh x5, x5, d |
| sbcs x5, x9, x5 |
| mul x5, x5, di |
| str x5, [rp],#8 |
| sub n, n, #1 |
| cbnz n, L(tpn) |
| |
| L(en1): ret |
| EPILOGUE() |
