dnl ARM v5 mpn_gcd_11.
dnl Based on the K7 gcd_1.asm, by Kevin Ryde. Rehacked
for ARM by Torbjörn
dnl Granlund.
dnl Copyright 2000-2002, 2005, 2009, 2011, 2012 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/bit (approx)
C StrongARM -
C XScale ?
C Cortex-A5 6.45 obsolete
C Cortex-A7 6.41 obsolete
C Cortex-A8 5.0 obsolete
C Cortex-A9 5.9 obsolete
C Cortex-A15 4.40 obsolete
C Cortex-A17 5.68 obsolete
C Cortex-A53 4.37 obsolete
C Numbers measured with: speed -CD -s8-32 -t24 mpn_gcd_1
define(`u0
', `r0')
define(`v0
', `r1')
ASM_START()
TEXT
ALIGN(16)
PROLOGUE(mpn_gcd_11)
subs r3, u0, v0 C 0
beq L(
end) C
ALIGN(16)
L(top):
sub r2, v0, u0 C 0,5
and r12, r2, r3 C 1
clz r12, r12 C 2
rsb r12, r12, #31 C 3
rsbcc r3, r3, #0 C v = abs(u-v),
even 1
movcs u0, v0 C u = min(u,v) 1
lsr v0, r3, r12 C 4
subs r3, u0, v0 C 5
bne L(top) C
L(
end): bx lr
EPILOGUE()
