dnl ARM mpn_copyi.
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_copyi)
tst n, #1
beq L(skip1)
ldr r3, [up], #4
str r3, [rp], #4
L(skip1):
tst n, #2
beq L(skip2)
ldmia up!, { r3,r12 }
stmia rp!, { r3,r12 }
L(skip2):
bics n, n, #3
beq L(rtn)
push { r4-r5 }
subs n, n, #4
ldmia up!, { r3,r4,r5,r12 }
beq L(
end)
L(top): subs n, n, #4
stmia rp!, { r3,r4,r5,r12 }
ldmia up!, { r3,r4,r5,r12 }
bne L(top)
L(
end): stm rp, { r3,r4,r5,r12 }
pop { r4-r5 }
L(rtn): return lr
EPILOGUE()
