mpir/mpn/pa64/udiv.asm

117 lines
3.0 KiB
NASM

dnl HP-PA 2.0 64-bit mpn_udiv_qrnnd_r.
dnl Copyright 2001, 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.
include(`../config.m4')
C This runs at about 280 cycles on both PA8000 and PA8500, corresponding to a
C bit more than 4 cycles/bit.
C INPUT PARAMETERS
define(`n1',`%r26')
define(`n0',`%r25')
define(`d',`%r24')
define(`remptr',`%r23')
define(`q',`%r28')
define(`dn',`%r29')
define(`old_divstep',
`add,dc n0,n0,n0
add,dc n1,n1,n1
sub,*<< n1,d,%r22
copy %r22,n1')
define(`divstep',
`add n0,n0,n0
add,dc n1,n1,n1
sub n1,d,%r1
add,dc q,q,q
cmpclr,*<< n1,d,%r0
copy %r1,n1
')
ifdef(`HAVE_ABI_2_0w',
` .level 2.0w
',` .level 2.0
')
PROLOGUE(mpn_udiv_qrnnd_r)
ifdef(`HAVE_ABI_2_0n',
` depd %r25,31,32,%r26
depd %r23,31,32,%r24
copy %r24,%r25
ldd -56(%r30),%r24
ldw -60(%r30),%r23
')
ldi 0,q
cmpib,*>= 0,d,L(large_divisor)
ldi 8,%r31 C setup loop counter
sub %r0,d,dn
LDEF(Loop)
divstep divstep divstep divstep divstep divstep divstep divstep
addib,<> -1,%r31,L(Loop)
nop
ifdef(`HAVE_ABI_2_0n',
` copy %r28,%r29
extrd,u %r28,31,32,%r28
')
bve (%r2)
std n1,0(remptr) C store remainder
LDEF(large_divisor)
extrd,u n0,63,1,%r19 C save lsb of dividend
shrpd n1,n0,1,n0 C n0 = lo(n1n0 >> 1)
shrpd %r0,n1,1,n1 C n1 = hi(n1n0 >> 1)
extrd,u d,63,1,%r20 C save lsb of divisor
shrpd %r0,d,1,d C d = floor(orig_d / 2)
add,l %r20,d,d C d = ceil(orig_d / 2)
sub %r0,d,dn
LDEF(Loop2)
divstep divstep divstep divstep divstep divstep divstep divstep
addib,<> -1,%r31,L(Loop2)
nop
cmpib,*= 0,%r20,L(even_divisor)
shladd n1,1,%r19,n1 C shift in omitted dividend lsb
add d,d,d C restore orig...
sub d,%r20,d C ...d value
sub %r0,d,dn C r21 = -d
add,*nuv n1,q,n1 C fix remainder for omitted divisor lsb
add,l n1,dn,n1 C adjust remainder if rem. fix carried
add,dc %r0,q,q C adjust quotient accordingly
sub,*<< n1,d,%r0 C remainder >= divisor?
add,l n1,dn,n1 C adjust remainder
add,dc %r0,q,q C adjust quotient
LDEF(even_divisor)
ifdef(`HAVE_ABI_2_0n',
` copy %r28,%r29
extrd,u %r28,31,32,%r28
')
bve (%r2)
std n1,0(remptr) C store remainder
EPILOGUE(mpn_udiv_qrnnd_r)