mpir/mpn/pa64/sub_n.asm

96 lines
2.7 KiB
NASM

dnl HP-PA 2.0 mpn_sub_n -- Subtract two limb vectors of the same length > 0
dnl and store difference in a third limb vector.
dnl Copyright 1997, 2000, 2002, 2003 Free Software Foundation, 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 2.1 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; see the file COPYING.LIB. If not, write
dnl to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
dnl Boston, MA 02110-1301, USA.
dnl This runs at 2 cycles/limb on PA8000 and 1.6875 cycles/limb on PA8500. It
dnl should be possible to reach the cache bandwith 1.5 cycles/limb at least
dnl with PA8500. The problem now is stalling of the first SUB,DB after LDO,
dnl where the processor gets confused about where carry comes from.
include(`../config.m4')
dnl INPUT PARAMETERS
define(`rp',`%r26')
define(`up',`%r25')
define(`vp',`%r24')
define(`n',`%r23')
ifdef(`HAVE_ABI_2_0w',
` .level 2.0w
',` .level 2.0
')
PROLOGUE(mpn_sub_n)
sub %r0, n, %r22
depw,z %r22, 30, 3, %r28 C r28 = 2 * (-n & 7)
depw,z %r22, 28, 3, %r22 C r22 = 8 * (-n & 7)
sub up, %r22, up C offset up
sub vp, %r22, vp C offset vp
blr %r28, %r0 C branch into loop
sub rp, %r22, rp C offset rp and set carry
LDEF(loop)
ldd 0(up), %r20
ldd 0(vp), %r31
sub,db %r20, %r31, %r20
std %r20, 0(rp)
LDEF(7) ldd 8(up), %r21
ldd 8(vp), %r19
sub,db %r21, %r19, %r21
std %r21, 8(rp)
LDEF(6) ldd 16(up), %r20
ldd 16(vp), %r31
sub,db %r20, %r31, %r20
std %r20, 16(rp)
LDEF(5) ldd 24(up), %r21
ldd 24(vp), %r19
sub,db %r21, %r19, %r21
std %r21, 24(rp)
LDEF(4) ldd 32(up), %r20
ldd 32(vp), %r31
sub,db %r20, %r31, %r20
std %r20, 32(rp)
LDEF(3) ldd 40(up), %r21
ldd 40(vp), %r19
sub,db %r21, %r19, %r21
std %r21, 40(rp)
LDEF(2) ldd 48(up), %r20
ldd 48(vp), %r31
sub,db %r20, %r31, %r20
std %r20, 48(rp)
LDEF(1) ldd 56(up), %r21
ldd 56(vp),%r19
sub,db %r21, %r19, %r21
ldo 64(up), up
std %r21, 56(rp)
ldo 64(vp), vp
addib,> -8, n, L(loop)
ldo 64(rp), rp
add,dc %r0, %r0, %r29
subi 1, %r29, %r29
bve (%r2)
ifdef(`HAVE_ABI_2_0w',
` copy %r29, %r28
',` ldi 0, %r28
')
EPILOGUE(mpn_sub_n)