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dnl SPARC64 mpn_gcd_11.
dnl Based on the K7 gcd_1.asm, by Kevin Ryde. Rehacked for SPARC by Torbjörn
dnl Granlund.
dnl Copyright 2000-2002, 2005, 2009, 2011-2013, 2021 Free Software Foundation,
dnl 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 UltraSPARC 1&2: 5.1
C UltraSPARC 3: 5.0
C UltraSPARC T1: 11.4
C UltraSPARC T3: 10
C UltraSPARC T4: 6
C Numbers measured with: speed -CD -s32-64 -t32 mpn_gcd_1
C ctz_table[n] is the number of trailing zeros on n, or MAXSHIFT if n==0.
deflit(MAXSHIFT, 7)
deflit(MASK, eval((m4_lshift(1,MAXSHIFT))-1))
RODATA
TYPE(ctz_table,object)
ctz_table:
.byte MAXSHIFT
forloop(i,1,MASK,
` .byte m4_count_trailing_zeros(i)
')
SIZE(ctz_table,.-ctz_table)
define(`u0', `%o0')
define(`v0', `%o1')
ASM_START()
PROLOGUE(mpn_gcd_11)
LEA64(ctz_table, o5, g4)
b L(odd)
mov u0, %o4
ALIGN(16)
L(top): movcc %xcc, %o4, v0 C v = min(u,v)
movcc %xcc, %o2, %o0 C u = |v - u]
L(mid): ldub [%o5+%g1], %g5 C
brz,pn %g1, L(shift_alot) C
srlx %o0, %g5, %o4 C new u, odd
L(odd): subcc v0, %o4, %o2 C v - u, set flags for branch and movcc
sub %o4, v0, %o0 C u - v
bnz,pt %xcc, L(top) C
and %o2, MASK, %g1 C extract low MAXSHIFT bits from (v-u)
retl
mov v0, %o0
L(shift_alot):
mov %o4, %o0
b L(mid)
and %o4, MASK, %g1 C
EPILOGUE()
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