143 lines
4.0 KiB
ArmAsm
143 lines
4.0 KiB
ArmAsm
/* Optimized version of the standard strcpy() function.
|
|
This file is part of the GNU C Library.
|
|
Copyright (C) 2000 Free Software Foundation, Inc.
|
|
Contributed by Dan Pop <Dan.Pop@cern.ch>.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
/* Return: dest
|
|
|
|
Inputs:
|
|
in0: dest
|
|
in1: src
|
|
|
|
In this form, it assumes little endian mode. For big endian mode, the
|
|
the two shifts in .l2 must be inverted:
|
|
|
|
shl value = r[1], sh1 // value = w0 << sh1
|
|
shr.u tmp = r[0], sh2 // tmp = w1 >> sh2
|
|
*/
|
|
|
|
#include <sysdep.h>
|
|
#undef ret
|
|
|
|
#define saved_pfs r14
|
|
#define saved_lc r15
|
|
#define saved_pr r16
|
|
#define thresh r17
|
|
#define dest r19
|
|
#define src r20
|
|
#define len r21
|
|
#define asrc r22
|
|
#define tmp r23
|
|
#define pos r24
|
|
#define w0 r25
|
|
#define w1 r26
|
|
#define c r27
|
|
#define sh2 r28
|
|
#define sh1 r29
|
|
#define loopcnt r30
|
|
#define value r31
|
|
|
|
ENTRY(strcpy)
|
|
alloc saved_pfs = ar.pfs, 2, 0, 30, 32
|
|
|
|
#define MEMLAT 2
|
|
.rotr r[MEMLAT + 2]
|
|
.rotp p[MEMLAT + 1]
|
|
|
|
mov ret0 = in0 // return value = dest
|
|
mov saved_pr = pr // save the predicate registers
|
|
mov saved_lc = ar.lc // save the loop counter
|
|
sub tmp = r0, in0 ;; // tmp = -dest
|
|
mov dest = in0 // dest
|
|
mov src = in1 // src
|
|
and loopcnt = 7, tmp ;; // loopcnt = -dest % 8
|
|
cmp.eq p6, p0 = loopcnt, r0
|
|
adds loopcnt = -1, loopcnt // --loopcnt
|
|
(p6) br.cond.sptk .dest_aligned ;;
|
|
mov ar.lc = loopcnt
|
|
.l1: // copy -dest % 8 bytes
|
|
ld1 c = [src], 1 // c = *src++
|
|
;;
|
|
st1 [dest] = c, 1 // *dest++ = c
|
|
cmp.eq p6, p0 = c, r0
|
|
(p6) br.cond.dpnt .restore_and_exit
|
|
br.cloop.dptk .l1 ;;
|
|
.dest_aligned:
|
|
and sh1 = 7, src // sh1 = src % 8
|
|
mov ar.lc = -1 // "infinite" loop
|
|
and asrc = -8, src ;; // asrc = src & -OPSIZ -- align src
|
|
sub thresh = 8, sh1
|
|
mov pr.rot = 1 << 16 // set rotating predicates
|
|
cmp.ne p7, p0 = r0, r0 // clear p7
|
|
shl sh1 = sh1, 3 ;; // sh1 = 8 * (src % 8)
|
|
sub sh2 = 64, sh1 // sh2 = 64 - sh1
|
|
cmp.eq p6, p0 = sh1, r0 // is the src aligned?
|
|
(p6) br.cond.sptk .src_aligned ;;
|
|
ld8 r[1] = [asrc],8 ;;
|
|
|
|
.align 32
|
|
.l2:
|
|
ld8.s r[0] = [asrc], 8
|
|
shr.u value = r[1], sh1 ;; // value = w0 >> sh1
|
|
czx1.r pos = value ;; // do we have an "early" zero
|
|
cmp.lt p7, p0 = pos, thresh // in w0 >> sh1?
|
|
(p7) br.cond.dpnt .found0
|
|
chk.s r[0], .recovery2 // it is safe to do that only
|
|
.back2: // after the previous test
|
|
shl tmp = r[0], sh2 // tmp = w1 << sh2
|
|
;;
|
|
or value = value, tmp ;; // value |= tmp
|
|
czx1.r pos = value ;;
|
|
cmp.ne p7, p0 = 8, pos
|
|
(p7) br.cond.dpnt .found0
|
|
st8 [dest] = value, 8 // store val to dest
|
|
br.ctop.dptk .l2 ;;
|
|
.src_aligned:
|
|
.l3:
|
|
(p[0]) ld8.s r[0] = [src], 8
|
|
(p[MEMLAT]) chk.s r[MEMLAT], .recovery3
|
|
.back3:
|
|
(p[MEMLAT]) mov value = r[MEMLAT]
|
|
(p[MEMLAT]) czx1.r pos = r[MEMLAT] ;;
|
|
(p[MEMLAT]) cmp.ne p7, p0 = 8, pos
|
|
(p7) br.cond.dpnt .found0
|
|
(p[MEMLAT]) st8 [dest] = r[MEMLAT], 8
|
|
br.ctop.dptk .l3 ;;
|
|
.found0:
|
|
mov ar.lc = pos
|
|
.l4:
|
|
extr.u c = value, 0, 8 // c = value & 0xff
|
|
shr.u value = value, 8
|
|
;;
|
|
st1 [dest] = c, 1
|
|
br.cloop.dptk .l4 ;;
|
|
.restore_and_exit:
|
|
mov ar.pfs = saved_pfs // restore the PFS
|
|
mov ar.lc = saved_lc // restore the loop counter
|
|
mov pr = saved_pr, -1 // restore the predicate registers
|
|
br.ret.sptk.many b0
|
|
.recovery2:
|
|
add tmp = -8, asrc ;;
|
|
ld8 r[MEMLAT] = [tmp]
|
|
br.cond.sptk .back2
|
|
.recovery3:
|
|
add tmp = -(MEMLAT + 1) * 8, src ;;
|
|
ld8 r[MEMLAT] = [tmp]
|
|
br.cond.sptk .back3
|
|
END(strcpy)
|