| dnl HP-PA 1.1 mpn_submul_1 -- Multiply a limb vector with a limb and subtract |
| dnl the result from a second limb vector. |
| |
| dnl Copyright 1992, 1993, 1994, 2000, 2001, 2002 Free Software Foundation, |
| dnl Inc. |
| |
| dnl This file is part of the GNU MP Library. |
| |
| dnl The GNU MP Library is free software; you can redistribute it and/or modify |
| dnl it under the terms of the GNU Lesser General Public License as published |
| dnl by the Free Software Foundation; either version 3 of the License, or (at |
| dnl your option) any later version. |
| |
| 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 Lesser General Public |
| dnl License for more details. |
| |
| dnl You should have received a copy of the GNU Lesser General Public License |
| dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. |
| |
| include(`../config.m4') |
| |
| C INPUT PARAMETERS |
| C res_ptr r26 |
| C s1_ptr r25 |
| C size r24 |
| C s2_limb r23 |
| |
| C This runs at 12 cycles/limb on a PA7000. With the used instructions, it can |
| C not become faster due to data cache contention after a store. On the PA7100 |
| C it runs at 11 cycles/limb. |
| |
| C There are some ideas described in mul_1.asm that applies to this code too. |
| |
| C It seems possible to make this run as fast as mpn_addmul_1, if we use |
| C sub,>>= %r29,%r19,%r22 |
| C addi 1,%r28,%r28 |
| C but that requires reworking the hairy software pipeline... |
| |
| ASM_START() |
| PROLOGUE(mpn_submul_1) |
| C .callinfo frame=64,no_calls |
| |
| ldo 64(%r30),%r30 |
| fldws,ma 4(%r25),%fr5 |
| stw %r23,-16(%r30) C move s2_limb ... |
| addib,= -1,%r24,L(just_one_limb) |
| fldws -16(%r30),%fr4 C ... into fr4 |
| add %r0,%r0,%r0 C clear carry |
| xmpyu %fr4,%fr5,%fr6 |
| fldws,ma 4(%r25),%fr7 |
| fstds %fr6,-16(%r30) |
| xmpyu %fr4,%fr7,%fr8 |
| ldw -12(%r30),%r19 C least significant limb in product |
| ldw -16(%r30),%r28 |
| |
| fstds %fr8,-16(%r30) |
| addib,= -1,%r24,L(end) |
| ldw -12(%r30),%r1 |
| |
| C Main loop |
| LDEF(loop) |
| ldws 0(%r26),%r29 |
| fldws,ma 4(%r25),%fr5 |
| sub %r29,%r19,%r22 |
| add %r22,%r19,%r0 |
| stws,ma %r22,4(%r26) |
| addc %r28,%r1,%r19 |
| xmpyu %fr4,%fr5,%fr6 |
| ldw -16(%r30),%r28 |
| fstds %fr6,-16(%r30) |
| addc %r0,%r28,%r28 |
| addib,<> -1,%r24,L(loop) |
| ldw -12(%r30),%r1 |
| |
| LDEF(end) |
| ldw 0(%r26),%r29 |
| sub %r29,%r19,%r22 |
| add %r22,%r19,%r0 |
| stws,ma %r22,4(%r26) |
| addc %r28,%r1,%r19 |
| ldw -16(%r30),%r28 |
| ldws 0(%r26),%r29 |
| addc %r0,%r28,%r28 |
| sub %r29,%r19,%r22 |
| add %r22,%r19,%r0 |
| stws,ma %r22,4(%r26) |
| addc %r0,%r28,%r28 |
| bv 0(%r2) |
| ldo -64(%r30),%r30 |
| |
| LDEF(just_one_limb) |
| xmpyu %fr4,%fr5,%fr6 |
| ldw 0(%r26),%r29 |
| fstds %fr6,-16(%r30) |
| ldw -12(%r30),%r1 |
| ldw -16(%r30),%r28 |
| sub %r29,%r1,%r22 |
| add %r22,%r1,%r0 |
| stw %r22,0(%r26) |
| addc %r0,%r28,%r28 |
| bv 0(%r2) |
| ldo -64(%r30),%r30 |
| EPILOGUE() |
