glibc/sysdeps/sparc/sparc64/sub_n.S

55 lines
1.7 KiB
ArmAsm

/* SPARC v9 __mpn_sub_n -- Subtract two limb vectors of the same length > 0
and store difference in a third limb vector.
Copyright (C) 1995-2020 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.
The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library; see the file COPYING.LIB. If not,
see <https://www.gnu.org/licenses/>. */
#include <sysdep.h>
/* INPUT PARAMETERS
res_ptr %o0
s1_ptr %o1
s2_ptr %o2
size %o3 */
ENTRY(__mpn_sub_n)
sub %g0,%o3,%g5
sllx %o3,3,%g1
add %o1,%g1,%o1 ! make s1_ptr point at end
add %o2,%g1,%o2 ! make s2_ptr point at end
add %o0,%g1,%o0 ! make res_ptr point at end
mov 0,%o4 ! clear carry variable
sllx %g5,3,%o5 ! compute initial address index
1: ldx [%o2+%o5],%g1 ! load s2 limb
add %g5,1,%g5 ! increment loop count
ldx [%o1+%o5],%o3 ! load s1 limb
addcc %g1,%o4,%g1 ! add s2 limb and carry variable
movcc %xcc,0,%o4 ! if carry-out, o4 was 1; clear it
subcc %o3,%g1,%g1 ! subtract s1 limb from sum
stx %g1,[%o0+%o5] ! store result
add %o5,8,%o5 ! increment address index
brnz,pt %g5,1b
movcs %xcc,1,%o4 ! if s1 subtract gave carry, record it
retl
mov %o4,%o0
END(__mpn_sub_n)