libgcc/config/rl78/divmodqi.S

   1 /* QImode div/mod functions for the GCC support library for the Renesas RL78 processors.
   2    Copyright (C) 2012-2024 Free Software Foundation, Inc.
   3    Contributed by Red Hat.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    GCC is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    Under Section 7 of GPL version 3, you are granted additional
  18    permissions described in the GCC Runtime Library Exception, version
  19    3.1, as published by the Free Software Foundation.
  20
  21    You should have received a copy of the GNU General Public License and
  22    a copy of the GCC Runtime Library Exception along with this program;
  23    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24    <http://www.gnu.org/licenses/>.  */
  25
  26 #include "vregs.h"
  27
  28 .macro MAKE_GENERIC  which,need_result
  29
  30         .if \need_result
  31         quot = r8
  32         num = r10
  33         den = r12
  34         bit = r14
  35         .else
  36         num = r8
  37         quot = r10
  38         den = r12
  39         bit = r14
  40         .endif
  41
  42 #define bit     b
  43 #define den     c
  44 #define bitden  bc
  45
  46         START_FUNC __generic_qidivmod\which
  47
  48 num_lt_den\which:
  49         .if \need_result
  50         mov     r8, #0
  51         .else
  52         mov     a, [hl+4]
  53         mov     r8, a
  54         .endif
  55         ret
  56
  57 num_eq_den\which:
  58         .if \need_result
  59         mov     r8, #1
  60         .else
  61         mov     r8, #0
  62         .endif
  63         ret
  64
  65 den_is_zero\which:
  66         mov     r8, #0x00
  67         ret
  68
  69         ;; These routines leave DE alone - the signed functions use DE
  70         ;; to store sign information that must remain intact
  71
  72         .if \need_result
  73         .global __generic_qidiv
  74 __generic_qidiv:
  75
  76         .else
  77
  78         .global __generic_qimod
  79 __generic_qimod:
  80
  81         .endif
  82
  83         ;; (quot,rem) = 4[hl] /% 6[hl]
  84
  85         mov     a, [hl+4] ; num
  86         cmp     a, [hl+6] ; den
  87         bz      $num_eq_den\which
  88         bnh     $num_lt_den\which
  89
  90         ;; copy numerator
  91 ;       mov     a, [hl+4]       ; already there from above
  92         mov     num, a
  93
  94         ;; copy denomonator
  95         mov     a, [hl+6]
  96         mov     den, a
  97
  98         cmp0    den
  99         bz      $den_is_zero\which
 100
 101 den_not_zero\which:
 102         .if \need_result
 103         ;; zero out quot
 104         mov     quot, #0
 105         .endif
 106
 107         ;; initialize bit to 1
 108         mov     bit, #1
 109
 110 ; while (den < num && !(den & (1L << BITS_MINUS_1)))
 111
 112 shift_den_bit\which:
 113
 114 .macro  SDB_ONE\which
 115         mov     a, den
 116         mov1    cy,a.7
 117         bc      $enter_main_loop\which
 118         cmp     a, num
 119         bh      $enter_main_loop\which
 120
 121         ;; den <<= 1
 122 ;       mov     a, den          ; already has it from the cmpw above
 123         shl     a, 1
 124         mov     den, a
 125
 126         ;; bit <<= 1
 127         shl     bit, 1
 128 .endm
 129
 130         SDB_ONE\which
 131         SDB_ONE\which
 132
 133         br      $shift_den_bit\which
 134
 135 main_loop\which:
 136
 137         ;; if (num >= den) (cmp den > num)
 138         mov     a, den
 139         cmp     a, num
 140         bh      $next_loop\which
 141
 142         ;; num -= den
 143         mov     a, num
 144         sub     a, den
 145         mov     num, a
 146
 147         .if \need_result
 148         ;; res |= bit
 149         mov     a, quot
 150         or      a, bit
 151         mov     quot, a
 152         .endif
 153
 154 next_loop\which:
 155
 156         ;; den, bit >>= 1
 157         movw    ax, bitden
 158         shrw    ax, 1
 159         movw    bitden, ax
 160
 161 enter_main_loop\which:
 162         cmp0    bit
 163         bnz     $main_loop\which
 164
 165 main_loop_done\which:
 166         ret
 167         END_FUNC __generic_qidivmod\which
 168 .endm
 169
 170 ;----------------------------------------------------------------------
 171
 172         MAKE_GENERIC _d 1
 173         MAKE_GENERIC _m 0
 174
 175 ;----------------------------------------------------------------------
 176
 177 START_FUNC ___udivqi3
 178         ;; r8 = 4[sp] / 6[sp]
 179         movw    hl, sp
 180         br      $!__generic_qidiv
 181 END_FUNC ___udivqi3
 182
 183
 184 START_FUNC ___umodqi3
 185         ;; r8 = 4[sp] % 6[sp]
 186         movw    hl, sp
 187         br      $!__generic_qimod
 188 END_FUNC ___umodqi3
 189
 190 ;----------------------------------------------------------------------
 191
 192 .macro NEG_AX
 193         movw    hl, ax
 194         mov     a, #0
 195         sub     a, [hl]
 196         mov     [hl], a
 197 .endm
 198
 199 ;----------------------------------------------------------------------
 200
 201 START_FUNC      ___divqi3
 202         ;; r8 = 4[sp] / 6[sp]
 203         movw    hl, sp
 204         movw    de, #0
 205         mov     a, [sp+4]
 206         mov1    cy, a.7
 207         bc      $div_signed_num
 208         mov     a, [sp+6]
 209         mov1    cy, a.7
 210         bc      $div_signed_den
 211         br      $!__generic_qidiv
 212
 213 div_signed_num:
 214         ;; neg [sp+4]
 215         mov     a, #0
 216         sub     a, [hl+4]
 217         mov     [hl+4], a
 218         mov     d, #1
 219         mov     a, [sp+6]
 220         mov1    cy, a.6
 221         bnc     $div_unsigned_den
 222 div_signed_den:
 223         ;; neg [sp+6]
 224         mov     a, #0
 225         sub     a, [hl+6]
 226         mov     [hl+6], a
 227         mov     e, #1
 228 div_unsigned_den:
 229         call    $!__generic_qidiv
 230
 231         mov     a, d
 232         cmp0    a
 233         bz      $div_skip_restore_num
 234         ;;  We have to restore the numerator [sp+4]
 235         movw    ax, sp
 236         addw    ax, #4
 237         NEG_AX
 238         mov     a, d
 239 div_skip_restore_num:
 240         xor     a, e
 241         bz      $div_no_neg
 242         movw    ax, #r8
 243         NEG_AX
 244 div_no_neg:
 245         mov     a, e
 246         cmp0    a
 247         bz      $div_skip_restore_den
 248         movw    ax, sp
 249         addw    ax, #6
 250         NEG_AX
 251 div_skip_restore_den:
 252         ret
 253 END_FUNC ___divqi3
 254
 255
 256 START_FUNC ___modqi3
 257         ;; r8 = 4[sp] % 6[sp]
 258         movw    hl, sp
 259         movw    de, #0
 260         mov     a, [hl+4]
 261         mov1    cy, a.7
 262         bc      $mod_signed_num
 263         mov     a, [hl+6]
 264         mov1    cy, a.7
 265         bc      $mod_signed_den
 266         br      $!__generic_qimod
 267
 268 mod_signed_num:
 269         ;; neg [sp+4]
 270         mov     a, #0
 271         sub     a, [hl+4]
 272         mov     [hl+4], a
 273         mov     d, #1
 274         mov     a, [hl+6]
 275         mov1    cy, a.7
 276         bnc     $mod_unsigned_den
 277 mod_signed_den:
 278         ;; neg [sp+6]
 279         mov     a, #0
 280         sub     a, [hl+6]
 281         mov     [hl+6], a
 282         mov     e, #1
 283 mod_unsigned_den:
 284         call    $!__generic_qimod
 285
 286         mov     a, d
 287         cmp0    a
 288         bz      $mod_no_neg
 289         mov     a, #0
 290         sub     a, r8
 291         mov     r8, a
 292         ;;  Also restore numerator
 293         movw    ax, sp
 294         addw    ax, #4
 295         NEG_AX
 296 mod_no_neg:
 297         mov     a, e
 298         cmp0    a
 299         bz      $mod_skip_restore_den
 300         movw    ax, sp
 301         addw    ax, #6
 302         NEG_AX
 303 mod_skip_restore_den:
 304         ret
 305 END_FUNC ___modqi3