dnl ARM mpn_copyd.
dnl Contributed to the GNU project by Robert Harley and Torbjörn Granlund.
dnl Copyright 2003, 2012, 2013 Free Software Foundation, Inc.
dnl This file is part of the GNU MP Library.
dnl
dnl The GNU MP Library is free software; you can redistribute it and/or modify
dnl it under the terms of either:
dnl
dnl * the GNU Lesser General Public License as published by the Free
dnl Software Foundation; either version 3 of the License, or (at your
dnl option) any later version.
dnl
dnl or
dnl
dnl * the GNU General Public License as published by the Free Software
dnl Foundation; either version 2 of the License, or (at your option) any
dnl later version.
dnl
dnl or both in parallel, as here.
dnl
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 General Public License
dnl for more details.
dnl
dnl You should have received copies of the GNU General Public License and the
dnl GNU Lesser General Public License along with the GNU MP Library. If not,
dnl see https://www.gnu.org/licenses/.
include(`../config.m4')
C cycles/limb
C StrongARM ?
C XScale ?
C Cortex-A7 ?
C Cortex-A8 ?
C Cortex-A9 1.25-1.5
C Cortex-A15 1.25
C TODO
C * Consider wider unrolling. Analogous 8-way code runs 10% faster on both A9
C and A15. But it probably slows things down for 8 <= n < a few dozen.
define(`rp', `r0')
define(`up', `r1')
define(`n', `r2')
ASM_START()
PROLOGUE(mpn_copyd)
mov r12, n, lsl #2
sub r12, r12, #4
add rp, rp, r12
add up, up, r12
tst n, #1
beq L(skip1)
ldr r3, [up], #-4
str r3, [rp], #-4
L(skip1):
tst n, #2
beq L(skip2)
ldmda up!, { r3,r12 }
stmda rp!, { r3,r12 }
L(skip2):
bics n, n, #3
beq L(rtn)
push { r4-r5 }
subs n, n, #4
ldmda up!, { r3,r4,r5,r12 }
beq L(end)
L(top): subs n, n, #4
stmda rp!, { r3,r4,r5,r12 }
ldmda up!, { r3,r4,r5,r12 }
bne L(top)
L(end): stmda rp, { r3,r4,r5,r12 }
pop { r4-r5 }
L(rtn): ret lr
EPILOGUE()