Retro68/gcc/libgcc/config/epiphany/modsi3.S

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2012-03-27 23:13:14 +00:00
/* Signed 32 bit modulo optimized for Epiphany.
Copyright (C) 2009 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)