glibc/sysdeps/sparc/sparc64/rshift.S

93 lines
2.0 KiB
ArmAsm

/* SPARC v9 __mpn_rshift --
Copyright (C) 1996-2023 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
src_ptr %o1
size %o2
cnt %o3 */
.register %g2, #scratch
.register %g3, #scratch
ENTRY(__mpn_rshift)
ldx [%o1],%g2 ! load first limb
sub %g0,%o3,%o5 ! negate shift count
add %o2,-1,%o2
andcc %o2,4-1,%g4 ! number of limbs in first loop
sllx %g2,%o5,%g1 ! compute function result
be,pn %xcc,.L0 ! if multiple of 4 limbs, skip first loop
mov %g1,%g5
sub %o2,%g4,%o2 ! adjust count for main loop
.Loop0: ldx [%o1+8],%g3
add %o0,8,%o0
add %o1,8,%o1
srlx %g2,%o3,%o4
addcc %g4,-1,%g4
sllx %g3,%o5,%g1
mov %g3,%g2
or %o4,%g1,%o4
bne,pt %xcc,.Loop0
stx %o4,[%o0-8]
.L0: brz,pn %o2,.Lend
nop
.Loop: ldx [%o1+8],%g3
add %o0,32,%o0
srlx %g2,%o3,%o4
addcc %o2,-4,%o2
sllx %g3,%o5,%g1
ldx [%o1+16],%g2
srlx %g3,%o3,%g4
or %o4,%g1,%o4
stx %o4,[%o0-32]
sllx %g2,%o5,%g1
ldx [%o1+24],%g3
srlx %g2,%o3,%o4
or %g4,%g1,%g4
stx %g4,[%o0-24]
sllx %g3,%o5,%g1
ldx [%o1+32],%g2
srlx %g3,%o3,%g4
or %o4,%g1,%o4
stx %o4,[%o0-16]
sllx %g2,%o5,%g1
add %o1,32,%o1
or %g4,%g1,%g4
bne,pt %xcc,.Loop
stx %g4,[%o0-8]
.Lend: srlx %g2,%o3,%g2
stx %g2,[%o0-0]
jmpl %o7+8,%g0
mov %g5,%o0
END(__mpn_rshift)