source/libs/gmp/gmp-src/mpn/pa64/udiv.asm

   1 dnl  HP-PA 2.0 64-bit mpn_udiv_qrnnd_r.
   2
   3 dnl  Copyright 2001-2003 Free Software Foundation, Inc.
   4
   5 dnl  This file is part of the GNU MP Library.
   6 dnl
   7 dnl  The GNU MP Library is free software; you can redistribute it and/or modify
   8 dnl  it under the terms of either:
   9 dnl
  10 dnl    * the GNU Lesser General Public License as published by the Free
  11 dnl      Software Foundation; either version 3 of the License, or (at your
  12 dnl      option) any later version.
  13 dnl
  14 dnl  or
  15 dnl
  16 dnl    * the GNU General Public License as published by the Free Software
  17 dnl      Foundation; either version 2 of the License, or (at your option) any
  18 dnl      later version.
  19 dnl
  20 dnl  or both in parallel, as here.
  21 dnl
  22 dnl  The GNU MP Library is distributed in the hope that it will be useful, but
  23 dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  24 dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  25 dnl  for more details.
  26 dnl
  27 dnl  You should have received copies of the GNU General Public License and the
  28 dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
  29 dnl  see https://www.gnu.org/licenses/.
  30
  31 include(`../config.m4')
  32
  33 C This runs at about 280 cycles on both PA8000 and PA8500, corresponding to a
  34 C bit more than 4 cycles/bit.
  35
  36 C INPUT PARAMETERS
  37 define(`n1',`%r26')
  38 define(`n0',`%r25')
  39 define(`d',`%r24')
  40 define(`remptr',`%r23')
  41
  42 define(`q',`%r28')
  43 define(`dn',`%r29')
  44
  45 define(`old_divstep',
  46        `add,dc          n0,n0,n0
  47         add,dc          n1,n1,n1
  48         sub,*<<         n1,d,%r22
  49         copy            %r22,n1')
  50
  51 define(`divstep',
  52        `add             n0,n0,n0
  53         add,dc          n1,n1,n1
  54         sub             n1,d,%r1
  55         add,dc          q,q,q
  56         cmpclr,*<<      n1,d,%r0
  57         copy            %r1,n1
  58 ')
  59
  60 ifdef(`HAVE_ABI_2_0w',
  61 `       .level  2.0w
  62 ',`     .level  2.0
  63 ')
  64 PROLOGUE(mpn_udiv_qrnnd_r)
  65 ifdef(`HAVE_ABI_2_0n',
  66 `       depd            %r25,31,32,%r26
  67         depd            %r23,31,32,%r24
  68         copy            %r24,%r25
  69         ldd             -56(%r30),%r24
  70         ldw             -60(%r30),%r23
  71 ')
  72         ldi             0,q
  73         cmpib,*>=       0,d,L(large_divisor)
  74         ldi             8,%r31          C setup loop counter
  75
  76         sub             %r0,d,dn
  77 LDEF(Loop)
  78         divstep divstep divstep divstep divstep divstep divstep divstep
  79         addib,<>        -1,%r31,L(Loop)
  80         nop
  81
  82 ifdef(`HAVE_ABI_2_0n',
  83 `       copy            %r28,%r29
  84         extrd,u         %r28,31,32,%r28
  85 ')
  86         bve             (%r2)
  87         std             n1,0(remptr)    C store remainder
  88
  89 LDEF(large_divisor)
  90         extrd,u         n0,63,1,%r19    C save lsb of dividend
  91         shrpd           n1,n0,1,n0      C n0 = lo(n1n0 >> 1)
  92         shrpd           %r0,n1,1,n1     C n1 = hi(n1n0 >> 1)
  93         extrd,u         d,63,1,%r20     C save lsb of divisor
  94         shrpd           %r0,d,1,d       C d = floor(orig_d / 2)
  95         add,l           %r20,d,d        C d = ceil(orig_d / 2)
  96
  97         sub             %r0,d,dn
  98 LDEF(Loop2)
  99         divstep divstep divstep divstep divstep divstep divstep divstep
 100         addib,<>        -1,%r31,L(Loop2)
 101         nop
 102
 103         cmpib,*=        0,%r20,L(even_divisor)
 104         shladd          n1,1,%r19,n1    C shift in omitted dividend lsb
 105
 106         add             d,d,d           C restore orig...
 107         sub             d,%r20,d        C ...d value
 108         sub             %r0,d,dn        C r21 = -d
 109
 110         add,*nuv        n1,q,n1         C fix remainder for omitted divisor lsb
 111         add,l           n1,dn,n1        C adjust remainder if rem. fix carried
 112         add,dc          %r0,q,q         C adjust quotient accordingly
 113
 114         sub,*<<         n1,d,%r0        C remainder >= divisor?
 115         add,l           n1,dn,n1        C adjust remainder
 116         add,dc          %r0,q,q         C adjust quotient
 117
 118 LDEF(even_divisor)
 119 ifdef(`HAVE_ABI_2_0n',
 120 `       copy            %r28,%r29
 121         extrd,u         %r28,31,32,%r28
 122 ')
 123         bve             (%r2)
 124         std             n1,0(remptr)    C store remainder
 125 EPILOGUE(mpn_udiv_qrnnd_r)