mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 08:40:07 +00:00
95 lines
2.9 KiB
ArmAsm
95 lines
2.9 KiB
ArmAsm
/* Copyright (C) 1996, 2003 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Richard Henderson (rth@tamu.edu)
|
|
|
|
The GNU C 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 C 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 C Library. If not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* Return the address of a given character within a null-terminated
|
|
string, or null if it is not found.
|
|
|
|
This is generally scheduled for the EV5 (got to look out for my own
|
|
interests :-), but with EV4 needs in mind. There *should* be no more
|
|
stalls for the EV4 than there are for the EV5.
|
|
*/
|
|
|
|
#include <sysdep.h>
|
|
|
|
.set noreorder
|
|
.set noat
|
|
|
|
ENTRY(strchr)
|
|
#ifdef PROF
|
|
ldgp gp, 0(pv)
|
|
lda AT, _mcount
|
|
jsr AT, (AT), _mcount
|
|
.prologue 1
|
|
#else
|
|
.prologue 0
|
|
#endif
|
|
|
|
zapnot a1, 1, a1 # e0 : zero extend the search character
|
|
ldq_u t0, 0(a0) # .. e1 : load first quadword
|
|
sll a1, 8, t5 # e0 : replicate the search character
|
|
andnot a0, 7, v0 # .. e1 : align our loop pointer
|
|
or t5, a1, a1 # e0 :
|
|
lda t4, -1 # .. e1 : build garbage mask
|
|
sll a1, 16, t5 # e0 :
|
|
cmpbge zero, t0, t2 # .. e1 : bits set iff byte == zero
|
|
mskqh t4, a0, t4 # e0 :
|
|
or t5, a1, a1 # .. e1 :
|
|
sll a1, 32, t5 # e0 :
|
|
cmpbge zero, t4, t4 # .. e1 : bits set iff byte is garbage
|
|
or t5, a1, a1 # e0 :
|
|
xor t0, a1, t1 # .. e1 : make bytes == c zero
|
|
cmpbge zero, t1, t3 # e0 : bits set iff byte == c
|
|
or t2, t3, t0 # e1 : bits set iff char match or zero match
|
|
andnot t0, t4, t0 # e0 : clear garbage bits
|
|
bne t0, $found # .. e1 (zdb)
|
|
|
|
$loop: ldq t0, 8(v0) # e0 :
|
|
addq v0, 8, v0 # .. e1 :
|
|
nop # e0 :
|
|
xor t0, a1, t1 # .. e1 (ev5 data stall)
|
|
cmpbge zero, t0, t2 # e0 : bits set iff byte == 0
|
|
cmpbge zero, t1, t3 # .. e1 : bits set iff byte == c
|
|
or t2, t3, t0 # e0 :
|
|
beq t0, $loop # .. e1 (zdb)
|
|
|
|
$found: negq t0, t1 # e0 : clear all but least set bit
|
|
and t0, t1, t0 # e1 (stall)
|
|
|
|
and t0, t3, t1 # e0 : bit set iff byte was the char
|
|
beq t1, $retnull # .. e1 (zdb)
|
|
|
|
and t0, 0xf0, t2 # e0 : binary search for that set bit
|
|
and t0, 0xcc, t3 # .. e1 :
|
|
and t0, 0xaa, t4 # e0 :
|
|
cmovne t2, 4, t2 # .. e1 :
|
|
cmovne t3, 2, t3 # e0 :
|
|
cmovne t4, 1, t4 # .. e1 :
|
|
addq t2, t3, t2 # e0 :
|
|
addq v0, t4, v0 # .. e1 :
|
|
addq v0, t2, v0 # e0 :
|
|
ret # .. e1 :
|
|
|
|
$retnull:
|
|
mov zero, v0 # e0 :
|
|
ret # .. e1 :
|
|
|
|
END(strchr)
|
|
|
|
weak_alias (strchr, index)
|
|
libc_hidden_builtin_def (strchr)
|