140 lines
2.6 KiB
ArmAsm
140 lines
2.6 KiB
ArmAsm
/*
|
|
* User string length functions for kernel
|
|
*
|
|
* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 and
|
|
* only version 2 as published by the Free Software Foundation.
|
|
*
|
|
* This program 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.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
* 02110-1301, USA.
|
|
*/
|
|
|
|
#define isrc r0
|
|
#define max r1 /* Do not change! */
|
|
|
|
#define end r2
|
|
#define tmp1 r3
|
|
|
|
#define obo r6 /* off-by-one */
|
|
#define start r7
|
|
#define mod8 r8
|
|
#define dbuf r15:14
|
|
#define dcmp r13:12
|
|
|
|
/*
|
|
* The vector mask version of this turned out *really* badly.
|
|
* The hardware loop version also turned out *really* badly.
|
|
* Seems straight pointer arithmetic basically wins here.
|
|
*/
|
|
|
|
#define fname __strnlen_user
|
|
|
|
.text
|
|
.global fname
|
|
.type fname, @function
|
|
.p2align 5 /* why? */
|
|
fname:
|
|
{
|
|
mod8 = and(isrc,#7);
|
|
end = add(isrc,max);
|
|
start = isrc;
|
|
}
|
|
{
|
|
P0 = cmp.eq(mod8,#0);
|
|
mod8 = and(end,#7);
|
|
dcmp = #0;
|
|
if (P0.new) jump:t dw_loop; /* fire up the oven */
|
|
}
|
|
|
|
alignment_loop:
|
|
fail_1: {
|
|
tmp1 = memb(start++#1);
|
|
}
|
|
{
|
|
P0 = cmp.eq(tmp1,#0);
|
|
if (P0.new) jump:nt exit_found;
|
|
P1 = cmp.gtu(end,start);
|
|
mod8 = and(start,#7);
|
|
}
|
|
{
|
|
if (!P1) jump exit_error; /* hit the end */
|
|
P0 = cmp.eq(mod8,#0);
|
|
}
|
|
{
|
|
if (!P0) jump alignment_loop;
|
|
}
|
|
|
|
|
|
|
|
dw_loop:
|
|
fail_2: {
|
|
dbuf = memd(start);
|
|
obo = add(start,#1);
|
|
}
|
|
{
|
|
P0 = vcmpb.eq(dbuf,dcmp);
|
|
}
|
|
{
|
|
tmp1 = P0;
|
|
P0 = cmp.gtu(end,start);
|
|
}
|
|
{
|
|
tmp1 = ct0(tmp1);
|
|
mod8 = and(end,#7);
|
|
if (!P0) jump end_check;
|
|
}
|
|
{
|
|
P0 = cmp.eq(tmp1,#32);
|
|
if (!P0.new) jump:nt exit_found;
|
|
if (!P0.new) start = add(obo,tmp1);
|
|
}
|
|
{
|
|
start = add(start,#8);
|
|
jump dw_loop;
|
|
} /* might be nice to combine these jumps... */
|
|
|
|
|
|
end_check:
|
|
{
|
|
P0 = cmp.gt(tmp1,mod8);
|
|
if (P0.new) jump:nt exit_error; /* neverfound! */
|
|
start = add(obo,tmp1);
|
|
}
|
|
|
|
exit_found:
|
|
{
|
|
R0 = sub(start,isrc);
|
|
jumpr R31;
|
|
}
|
|
|
|
exit_error:
|
|
{
|
|
R0 = add(max,#1);
|
|
jumpr R31;
|
|
}
|
|
|
|
/* Uh, what does the "fixup" return here? */
|
|
.falign
|
|
fix_1:
|
|
{
|
|
R0 = #0;
|
|
jumpr R31;
|
|
}
|
|
|
|
.size fname,.-fname
|
|
|
|
|
|
.section __ex_table,"a"
|
|
.long fail_1,fix_1
|
|
.long fail_2,fix_1
|
|
.previous
|