84 lines
2.2 KiB
ArmAsm
84 lines
2.2 KiB
ArmAsm
/* Unsigned 32 bit division optimized for Epiphany.
|
|
Copyright (C) 2009-2017 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 (__udivsi3,T_UINT)
|
|
.global SYM(__udivsi3)
|
|
.balign 4
|
|
HIDDEN_FUNC(__udivsi3)
|
|
SYM(__udivsi3):
|
|
sub TMP0,r0,r1
|
|
bltu .Lret0
|
|
float TMP2,r0
|
|
mov TMP1,%low(0xb0800000) ; ??? this would be faster with small data
|
|
float TMP3,r1
|
|
movt TMP1,%high(0xb0800000)
|
|
asr TMP0,r0,8
|
|
sub TMP0,TMP0,TMP1
|
|
movt TMP1,%high(0x00810000)
|
|
movgteu TMP2,TMP0
|
|
bblt .Lret1
|
|
sub TMP2,TMP2,TMP1
|
|
sub TMP2,TMP2,TMP3
|
|
mov TMP3,0
|
|
movltu TMP2,TMP3
|
|
lsr TMP2,TMP2,23
|
|
lsl r1,r1,TMP2
|
|
mov TMP0,1
|
|
lsl TMP0,TMP0,TMP2
|
|
sub r0,r0,r1
|
|
bltu .Ladd_back
|
|
add TMP3,TMP3,TMP0
|
|
sub r0,r0,r1
|
|
bltu .Ladd_back
|
|
.Lsub_loop:; More than two iterations are rare, so it makes sense to leave
|
|
; this label here to reduce average branch penalties.
|
|
add TMP3,TMP3,TMP0
|
|
sub r0,r0,r1
|
|
bgteu .Lsub_loop
|
|
.Ladd_back:
|
|
add r0,r0,r1
|
|
sub TMP1,r1,1
|
|
mov r1,%low(.L0step)
|
|
movt r1,%high(.L0step)
|
|
lsl TMP2,TMP2,3
|
|
sub r1,r1,TMP2
|
|
jr r1
|
|
.rep 30
|
|
lsl r0,r0,1
|
|
sub.l r1,r0,TMP1
|
|
movgteu r0,r1
|
|
.endr
|
|
.L0step:sub r1,TMP0,1 ; mask result bits from steps ...
|
|
and r0,r0,r1
|
|
orr r0,r0,TMP3 ; ... and combine with first bits.
|
|
rts
|
|
.Lret0: mov r0,0
|
|
rts
|
|
.Lret1: mov r0,1
|
|
rts
|
|
ENDFUNC(__udivsi3)
|