source/libs/gmp/gmp-src/mpn/alpha/ev5/diveby3.asm

   1 dnl  Alpha mpn_divexact_by3c -- mpn division by 3, expecting no remainder.
   2
   3 dnl  Copyright 2004, 2005, 2009 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      cycles/limb
  34 C EV4:    22
  35 C EV5:    11.5
  36 C EV6:     6.3          Note that mpn_bdiv_dbm1c is faster
  37
  38 C TODO
  39 C  * Remove the unops, they benefit just ev6, which no longer uses this file.
  40 C  * Try prefetch for destination, using lds.
  41 C  * Improve feed-in code, by moving initial mulq earlier; make initial load
  42 C    to u0/u0 to save some copying.
  43 C  * Combine u0 and u2, u1 and u3.
  44
  45 C INPUT PARAMETERS
  46 define(`rp',    `r16')
  47 define(`up',    `r17')
  48 define(`n',     `r18')
  49 define(`cy',    `r19')
  50
  51 ASM_START()
  52
  53 DATASTART(L(LC),8)
  54         .quad   0xAAAAAAAAAAAAAAAB
  55         .quad   0x5555555555555555
  56         .quad   0xAAAAAAAAAAAAAAAA
  57 DATAEND()
  58
  59 define(`xAAAAAAAAAAAAAAAB',     `r20')
  60 define(`x5555555555555555',     `r21')
  61 define(`xAAAAAAAAAAAAAAAA',     `r22')
  62 define(`u0',    `r0')   define(`u1',    `r1')
  63 define(`u2',    `r2')   define(`u3',    `r3')
  64 define(`l0',    `r25')  define(`x',     `r8')
  65 define(`q0',    `r4')   define(`q1',    `r5')
  66 define(`p6',    `r6')   define(`p7',    `r7')
  67 define(`t0',    `r23')  define(`t1',    `r24')
  68 define(`cymask',`r28')
  69
  70
  71 PROLOGUE(mpn_divexact_by3c,gp)
  72
  73         ldq     r28, 0(up)                      C load first limb early
  74
  75 C Put magic constants in registers
  76         lda     r0, L(LC)
  77         ldq     xAAAAAAAAAAAAAAAB, 0(r0)
  78         ldq     x5555555555555555, 8(r0)
  79         ldq     xAAAAAAAAAAAAAAAA, 16(r0)
  80
  81 C Compute initial l0 value
  82         cmpeq   cy, 1, p6
  83         cmpeq   cy, 2, p7
  84         negq    p6, p6
  85         and     p6, x5555555555555555, l0
  86         cmovne  p7, xAAAAAAAAAAAAAAAA, l0
  87
  88 C Feed-in depending on (n mod 4)
  89         and     n, 3, r8
  90         lda     n, -3(n)
  91         cmpeq   r8, 1, r4
  92         cmpeq   r8, 2, r5
  93         bne     r4, $Lb01
  94         bne     r5, $Lb10
  95         beq     r8, $Lb00
  96
  97 $Lb11:  ldq     u3, 8(up)
  98         lda     up, -24(up)
  99         lda     rp, -24(rp)
 100         mulq    r28, xAAAAAAAAAAAAAAAB, q0
 101         mov     r28, u2
 102         br      r31, $L11
 103
 104 $Lb00:  ldq     u2, 8(up)
 105         lda     up, -16(up)
 106         lda     rp, -16(rp)
 107         mulq    r28, xAAAAAAAAAAAAAAAB, q1
 108         mov     r28, u1
 109         br      r31, $L00
 110
 111 $Lb01:  lda     rp, -8(rp)
 112         mulq    r28, xAAAAAAAAAAAAAAAB, q0
 113         mov     r28, u0
 114         blt     n, $Lcj1
 115         ldq     u1, 8(up)
 116         lda     up, -8(up)
 117         br      r31, $L01
 118
 119 $Lb10:  ldq     u0, 8(up)
 120         mulq    r28, xAAAAAAAAAAAAAAAB, q1
 121         mov     r28, u3
 122         blt     n, $Lend
 123
 124         ALIGN(16)
 125 $Ltop:
 126 C 0
 127         cmpult  u3, cy, cy                      C L0
 128         mulq    u0, xAAAAAAAAAAAAAAAB, q0       C U1
 129         ldq     u1, 16(up)                      C L1
 130         addq    q1, l0, x                       C U0
 131 C 1
 132         negq    cy, cymask                      C L0
 133         unop                                    C U1
 134         unop                                    C L1
 135         cmpult  x5555555555555555, x, p6        C U0
 136 C 2
 137         cmpult  xAAAAAAAAAAAAAAAA, x, p7        C U1
 138         unop
 139         unop
 140         negq    p6, t0                          C L0
 141 C 3
 142         negq    p7, t1                          C L0
 143         and     cymask, x5555555555555555, l0   C U1
 144         addq    p6, cy, cy
 145         and     t0, x5555555555555555, t0
 146 C 4
 147         and     t1, x5555555555555555, t1
 148         addq    p7, cy, cy
 149         unop
 150         addq    t0, l0, l0
 151 C 5
 152         addq    t1, l0, l0
 153         unop
 154         stq     x, 0(rp)                        C L1
 155         unop
 156 $L01:
 157 C 0
 158         cmpult  u0, cy, cy                      C L0
 159         mulq    u1, xAAAAAAAAAAAAAAAB, q1       C U1
 160         ldq     u2, 24(up)                      C L1
 161         addq    q0, l0, x                       C U0
 162 C 1
 163         negq    cy, cymask                      C L0
 164         unop                                    C U1
 165         unop                                    C L1
 166         cmpult  x5555555555555555, x, p6        C U0
 167 C 2
 168         cmpult  xAAAAAAAAAAAAAAAA, x, p7        C U1
 169         unop
 170         unop
 171         negq    p6, t0                          C L0
 172 C 3
 173         negq    p7, t1                          C L0
 174         and     cymask, x5555555555555555, l0   C U1
 175         addq    p6, cy, cy
 176         and     t0, x5555555555555555, t0
 177 C 4
 178         and     t1, x5555555555555555, t1
 179         addq    p7, cy, cy
 180         unop
 181         addq    t0, l0, l0
 182 C 5
 183         addq    t1, l0, l0
 184         unop
 185         stq     x, 8(rp)                        C L1
 186         unop
 187 $L00:
 188 C 0
 189         cmpult  u1, cy, cy                      C L0
 190         mulq    u2, xAAAAAAAAAAAAAAAB, q0       C U1
 191         ldq     u3, 32(up)                      C L1
 192         addq    q1, l0, x                       C U0
 193 C 1
 194         negq    cy, cymask                      C L0
 195         unop                                    C U1
 196         unop                                    C L1
 197         cmpult  x5555555555555555, x, p6        C U0
 198 C 2
 199         cmpult  xAAAAAAAAAAAAAAAA, x, p7        C U1
 200         unop
 201         unop
 202         negq    p6, t0                          C L0
 203 C 3
 204         negq    p7, t1                          C L0
 205         and     cymask, x5555555555555555, l0   C U1
 206         addq    p6, cy, cy
 207         and     t0, x5555555555555555, t0
 208 C 4
 209         and     t1, x5555555555555555, t1
 210         addq    p7, cy, cy
 211         unop
 212         addq    t0, l0, l0
 213 C 5
 214         addq    t1, l0, l0
 215         unop
 216         stq     x, 16(rp)                       C L1
 217         unop
 218 $L11:
 219 C 0
 220         cmpult  u2, cy, cy                      C L0
 221         mulq    u3, xAAAAAAAAAAAAAAAB, q1       C U1
 222         ldq     u0, 40(up)                      C L1
 223         addq    q0, l0, x                       C U0
 224 C 1
 225         negq    cy, cymask                      C L0
 226         unop                                    C U1
 227         unop                                    C L1
 228         cmpult  x5555555555555555, x, p6        C U0
 229 C 2
 230         cmpult  xAAAAAAAAAAAAAAAA, x, p7        C U1
 231         lda     n, -4(n)                        C L1 bookkeeping
 232         unop
 233         negq    p6, t0                          C L0
 234 C 3
 235         negq    p7, t1                          C L0
 236         and     cymask, x5555555555555555, l0   C U1
 237         addq    p6, cy, cy
 238         and     t0, x5555555555555555, t0
 239 C 4
 240         and     t1, x5555555555555555, t1
 241         addq    p7, cy, cy
 242         unop
 243         addq    t0, l0, l0
 244 C 5
 245         addq    t1, l0, l0
 246         unop
 247         stq     x, 24(rp)                       C L1
 248         lda     up, 32(up)
 249 C
 250         ldl     r31, 256(up)                    C prefetch
 251         unop
 252         lda     rp, 32(rp)
 253         bge     n, $Ltop                        C U1
 254 C *** MAIN LOOP END ***
 255 $Lend:
 256
 257         cmpult  u3, cy, cy                      C L0
 258         mulq    u0, xAAAAAAAAAAAAAAAB, q0       C U1
 259         unop
 260         addq    q1, l0, x                       C U0
 261 C 1
 262         negq    cy, cymask                      C L0
 263         unop                                    C U1
 264         unop                                    C L1
 265         cmpult  x5555555555555555, x, p6        C U0
 266 C 2
 267         cmpult  xAAAAAAAAAAAAAAAA, x, p7        C U1
 268         unop
 269         unop
 270         negq    p6, t0                          C L0
 271 C 3
 272         negq    p7, t1                          C L0
 273         and     cymask, x5555555555555555, l0   C U1
 274         addq    p6, cy, cy
 275         and     t0, x5555555555555555, t0
 276 C 4
 277         and     t1, x5555555555555555, t1
 278         addq    p7, cy, cy
 279         unop
 280         addq    t0, l0, l0
 281 C 5
 282         addq    t1, l0, l0
 283         unop
 284         stq     x, 0(rp)                        C L1
 285         unop
 286 $Lcj1:
 287         cmpult  u0, cy, cy                      C L0
 288         addq    q0, l0, x                       C U0
 289         cmpult  x5555555555555555, x, p6        C U0
 290         cmpult  xAAAAAAAAAAAAAAAA, x, p7        C U1
 291         addq    p6, cy, cy
 292         addq    p7, cy, r0
 293         stq     x, 8(rp)                        C L1
 294
 295         ret     r31,(r26),1
 296 EPILOGUE()
 297 ASM_END()
 298
 299 C This is useful for playing with various schedules.
 300 C Expand as: one(0)one(1)one(2)one(3)
 301 define(`one',`
 302 C 0
 303         cmpult  `$'eval(($1+3)%4), cy, cy               C L0
 304         mulq    `$'$1, xAAAAAAAAAAAAAAAB, `$'eval(4+$1%2) C U1
 305         ldq     `$'eval(($1+1)%4), eval($1*8+16)(up)    C L1
 306         addq    `$'eval(4+($1+1)%2), l0, x              C U0
 307 C 1
 308         negq    cy, cymask                              C L0
 309         unop                                            C U1
 310         unop                                            C L1
 311         cmpult  x5555555555555555, x, p6                C U0
 312 C 2
 313         cmpult  xAAAAAAAAAAAAAAAA, x, p7                C U1
 314         unop
 315         unop
 316         negq    p6, t0                                  C L0
 317 C 3
 318         negq    p7, t1                                  C L0
 319         and     cymask, x5555555555555555, l0           C U1
 320         addq    p6, cy, cy
 321         and     t0, x5555555555555555, t0
 322 C 4
 323         and     t1, x5555555555555555, t1
 324         addq    p7, cy, cy
 325         unop
 326         addq    t0, l0, l0
 327 C 5
 328         addq    t1, l0, l0
 329         unop
 330         stq     x, eval($1*8)(rp)                       C L1
 331         unop
 332 ')