gcc/libgcc/config/epiphany/modsi3.S
2021-01-04 10:26:59 +01:00

78 lines
2.2 KiB
ArmAsm

/* Signed 32 bit modulo optimized for Epiphany.
Copyright (C) 2009-2021 Free Software Foundation, Inc.
Contributed by Embecosm on behalf of Adapteva, Inc.
This file is part of GCC.
This file is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.
This file 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
General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "epiphany-asm.h"
FSTAB (__modsi3,T_INT)
.global SYM(__modsi3)
.balign 4
HIDDEN_FUNC(__modsi3)
SYM(__modsi3):
asr r17,r0,31 ; save sign
mov r2,0
sub r3,r2,r0
movgt r0,r3
sub r3,r2,r1
movgt r1,r3
movt r2,0xa000 ; 0xa0000000
orr r3,r2,r0
lsr r15,r0,16
movt r15,0xa800
movne r3,r15
lsr r16,r2,2 ; 0x28000000
and r15,r3,r16
fadd r12,r3,r15
orr r3,r2,r1
lsr r2,r1,16
movt r2,0xa800
movne r3,r2
and r2,r16,r3
fadd r3,r3,r2
sub r2,r0,r1
bltu .Lret_a
lsr r12,r12,23
mov r2,%low(.L0step)
movt r2,%high(.L0step)
lsr r3,r3,23
sub r3,r12,r3 ; calculate bit number difference.
lsl r3,r3,3
sub r2,r2,r3
jr r2
/* lsl_l r2,r1,n` sub r2,r0,r2` movgteu r0,r2 */
#define STEP(n) .long 0x0006441f | (n) << 5` sub r2,r0,r2` movgteu r0,r2
.balign 8,,2
STEP(31)` STEP(30)` STEP(29)` STEP(28)`
STEP(27)` STEP(26)` STEP(25)` STEP(24)`
STEP(23)` STEP(22)` STEP(21)` STEP(20)`
STEP(19)` STEP(18)` STEP(17)` STEP(16)`
STEP(15)` STEP(14)` STEP(13)` STEP(12)`
STEP(11)` STEP(10)` STEP(9)` STEP(8)`
STEP(7)` STEP(6)` STEP(5)` STEP(4)` STEP(3)` STEP(2)` STEP(1)
.L0step:STEP(0)
.Lret_a:eor r0,r0,r17 ; restore sign
sub r0,r0,r17
rts
ENDFUNC(__modsi3)