source/libs/gmp/gmp-src/mpn/arm/v7a/cora15/aors_n.asm

   1 dnl  ARM mpn_add_n/mpn_sub_n optimised for A15.
   2
   3 dnl  Copyright 2013 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                best
  34 C StrongARM:     -
  35 C XScale         ?
  36 C Cortex-A7      ?
  37 C Cortex-A8      ?
  38 C Cortex-A9      3.55                   2.5
  39 C Cortex-A15     1.27                   this
  40
  41 C This was a major improvement compared to the code we had before, but it might
  42 C not be the best 8-way code possible.  We've tried some permutations of auto-
  43 C increments and separate pointer updates, but they all ran at the same speed
  44 C on A15.
  45
  46 C Architecture requirements:
  47 C v5    -
  48 C v5t   -
  49 C v5te  ldrd strd
  50 C v6    -
  51 C v6t2  -
  52 C v7a   -
  53
  54 define(`rp', `r0')
  55 define(`up', `r1')
  56 define(`vp', `r2')
  57 define(`n',  `r3')
  58
  59 ifdef(`OPERATION_add_n', `
  60   define(`ADDSUBC',     adcs)
  61   define(`IFADD',       `$1')
  62   define(`SETCY',       `cmp    $1, #1')
  63   define(`RETVAL',      `adc    r0, n, #0')
  64   define(`RETVAL2',     `adc    r0, n, #1')
  65   define(`func',        mpn_add_n)
  66   define(`func_nc',     mpn_add_nc)')
  67 ifdef(`OPERATION_sub_n', `
  68   define(`ADDSUBC',     sbcs)
  69   define(`IFADD',       `')
  70   define(`SETCY',       `rsbs   $1, $1, #0')
  71   define(`RETVAL',      `sbc    r0, r0, r0
  72                         and     r0, r0, #1')
  73   define(`RETVAL2',     `RETVAL')
  74   define(`func',        mpn_sub_n)
  75   define(`func_nc',     mpn_sub_nc)')
  76
  77 MULFUNC_PROLOGUE(mpn_add_n mpn_add_nc mpn_sub_n mpn_sub_nc)
  78
  79 ASM_START()
  80 PROLOGUE(func_nc)
  81         ldr     r12, [sp]
  82         b       L(ent)
  83 EPILOGUE()
  84 PROLOGUE(func)
  85         mov     r12, #0
  86 L(ent): push    { r4-r9 }
  87
  88         ands    r6, n, #3
  89         mov     n, n, lsr #2
  90         beq     L(b00)
  91         cmp     r6, #2
  92         bcc     L(b01)
  93         beq     L(b10)
  94
  95 L(b11): ldr     r5, [up], #4
  96         ldr     r7, [vp], #4
  97         SETCY(  r12)
  98         ADDSUBC r9, r5, r7
  99         ldrd    r4, r5, [up, #0]
 100         ldrd    r6, r7, [vp, #0]
 101         str     r9, [rp], #-4
 102         b       L(lo)
 103
 104 L(b00): ldrd    r4, r5, [up], #-8
 105         ldrd    r6, r7, [vp], #-8
 106         SETCY(  r12)
 107         sub     rp, rp, #16
 108         b       L(mid)
 109
 110 L(b01): ldr     r5, [up], #-4
 111         ldr     r7, [vp], #-4
 112         SETCY(  r12)
 113         ADDSUBC r9, r5, r7
 114         str     r9, [rp], #-12
 115         tst     n, n
 116         beq     L(wd1)
 117 L(gt1): ldrd    r4, r5, [up, #8]
 118         ldrd    r6, r7, [vp, #8]
 119         b       L(mid)
 120
 121 L(b10): ldrd    r4, r5, [up]
 122         ldrd    r6, r7, [vp]
 123         SETCY(  r12)
 124         sub     rp, rp, #8
 125         b       L(lo)
 126
 127         ALIGN(16)
 128 L(top): ldrd    r4, r5, [up, #8]
 129         ldrd    r6, r7, [vp, #8]
 130         strd    r8, r9, [rp, #8]
 131 L(mid): ADDSUBC r8, r4, r6
 132         ADDSUBC r9, r5, r7
 133         ldrd    r4, r5, [up, #16]
 134         ldrd    r6, r7, [vp, #16]
 135         strd    r8, r9, [rp, #16]
 136         ADDSUBC r8, r4, r6
 137         ADDSUBC r9, r5, r7
 138         sub     n, n, #2
 139         tst     n, n
 140         bmi     L(dne)
 141         ldrd    r4, r5, [up, #24]
 142         ldrd    r6, r7, [vp, #24]
 143         strd    r8, r9, [rp, #24]
 144         ADDSUBC r8, r4, r6
 145         ADDSUBC r9, r5, r7
 146         ldrd    r4, r5, [up, #32]!
 147         ldrd    r6, r7, [vp, #32]!
 148         strd    r8, r9, [rp, #32]!
 149 L(lo):  ADDSUBC r8, r4, r6
 150         ADDSUBC r9, r5, r7
 151         tst     n, n
 152         bne     L(top)
 153
 154 L(end): strd    r8, r9, [rp, #8]
 155 L(wd1): RETVAL
 156         pop     { r4-r9 }
 157         bx      r14
 158 L(dne): strd    r8, r9, [rp, #24]
 159         RETVAL2
 160         pop     { r4-r9 }
 161         bx      r14
 162 EPILOGUE()