233 lines
6.0 KiB
ArmAsm
233 lines
6.0 KiB
ArmAsm
/* Optimized version of the standard strncpy() function.
|
|
This file is part of the GNU C Library.
|
|
Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
|
|
Contributed by Dan Pop <Dan.Pop@cern.ch>
|
|
and Jakub Jelinek <jakub@redhat.com>.
|
|
|
|
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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
/* Return: dest
|
|
|
|
Inputs:
|
|
in0: dest
|
|
in1: src
|
|
in2: len
|
|
|
|
In this form, it assumes little endian mode.
|
|
*/
|
|
|
|
#include <sysdep.h>
|
|
#undef ret
|
|
|
|
#define saved_lc r15
|
|
#define saved_pr r16
|
|
#define thresh r17
|
|
#define dest r18
|
|
#define dest2 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(strncpy)
|
|
.prologue
|
|
alloc r2 = ar.pfs, 3, 0, 29, 32
|
|
|
|
#define MEMLAT 2
|
|
.rotr r[MEMLAT + 2]
|
|
.rotp p[MEMLAT + 1]
|
|
|
|
mov ret0 = in0 // return value = dest
|
|
.save pr, saved_pr
|
|
mov saved_pr = pr // save the predicate registers
|
|
.save ar.lc, saved_lc
|
|
mov saved_lc = ar.lc // save the loop counter
|
|
mov ar.ec = 0 // ec is not guaranteed to
|
|
// be zero upon function entry
|
|
.body
|
|
cmp.geu p6, p5 = 24, in2
|
|
(p6) br.cond.spnt .short_len
|
|
sub tmp = r0, in0 ;; // tmp = -dest
|
|
mov len = in2 // len
|
|
mov dest = in0 // dest
|
|
mov src = in1 // src
|
|
and tmp = 7, tmp ;; // loopcnt = -dest % 8
|
|
cmp.eq p6, p7 = tmp, r0
|
|
adds loopcnt = -1, tmp // --loopcnt
|
|
(p6) br.cond.sptk .dest_aligned ;;
|
|
sub len = len, tmp // len -= -dest % 8
|
|
mov ar.lc = loopcnt
|
|
.l1: // copy -dest % 8 bytes
|
|
(p5) ld1 c = [src], 1 // c = *src++
|
|
;;
|
|
st1 [dest] = c, 1 // *dest++ = c
|
|
cmp.ne p5, p7 = c, r0
|
|
br.cloop.dptk .l1 ;;
|
|
(p7) br.cond.dpnt .found0_align
|
|
|
|
.dest_aligned: // p7 should be cleared here
|
|
shr.u c = len, 3 // c = len / 8
|
|
and sh1 = 7, src // sh1 = src % 8
|
|
and asrc = -8, src ;; // asrc = src & -OPSIZ -- align src
|
|
adds c = (MEMLAT-1), c // c = (len / 8) + MEMLAT - 1
|
|
sub thresh = 8, sh1
|
|
mov pr.rot = 1 << 16 // set rotating predicates
|
|
shl sh1 = sh1, 3 ;; // sh1 = 8 * (src % 8)
|
|
mov ar.lc = c // "infinite" loop
|
|
sub sh2 = 64, sh1 // sh2 = 64 - sh1
|
|
cmp.eq p6, p0 = sh1, r0 // is the src aligned?
|
|
(p6) br.cond.sptk .src_aligned
|
|
adds c = -(MEMLAT-1), c ;; // c = (len / 8)
|
|
ld8 r[1] = [asrc],8
|
|
mov ar.lc = c ;;
|
|
|
|
.align 32
|
|
.l2:
|
|
(p6) st8 [dest] = value, 8 // store val to dest
|
|
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?
|
|
adds len = -8, len // len -= 8
|
|
(p7) br.cond.dpnt .nonalign_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, p6 = 8, pos
|
|
(p7) br.cond.dpnt .nonalign_found0
|
|
br.ctop.dptk .l2 ;;
|
|
adds len = 8, len
|
|
br.cond.sptk .not_found0 ;;
|
|
.nonalign_found0:
|
|
cmp.gtu p6, p0 = -8, len
|
|
(p6) br.cond.dptk .found0
|
|
adds len = 8, len
|
|
br.cond.sptk .not_found0 ;;
|
|
|
|
.align 32
|
|
.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
|
|
(p[MEMLAT]) adds len = -8, len // len -= 8
|
|
(p7) br.cond.dpnt .found0
|
|
(p[MEMLAT]) st8 [dest] = r[MEMLAT], 8
|
|
br.ctop.dptk .l3 ;;
|
|
|
|
chk.s r[MEMLAT-1], .recovery4
|
|
.back4:
|
|
mov value = r[MEMLAT-1]
|
|
|
|
.not_found0:
|
|
cmp.eq p5, p6 = len, r0
|
|
adds len = -1, len
|
|
(p5) br.cond.dptk .restore_and_exit ;;
|
|
mov ar.lc = len
|
|
.l4:
|
|
(p6) extr.u c = value, 0, 8 // c = value & 0xff
|
|
(p6) shr.u value = value, 8 ;;
|
|
st1 [dest] = c, 1
|
|
cmp.ne p6, p0 = c, r0
|
|
br.cloop.dptk .l4
|
|
br.cond.sptk .restore_and_exit
|
|
|
|
.found0_align:
|
|
mov pos = 0
|
|
adds len = -8, len
|
|
mov value = 0 ;;
|
|
.found0:
|
|
shl tmp = pos, 3
|
|
shr.u loopcnt = len, 4 // loopcnt = len / 16
|
|
mov c = -1 ;;
|
|
cmp.eq p6, p0 = loopcnt, r0
|
|
adds loopcnt = -1, loopcnt
|
|
shl c = c, tmp ;;
|
|
and len = 0xf, len
|
|
andcm value = value, c
|
|
mov ar.lc = loopcnt ;;
|
|
cmp.le p7, p0 = 8, len
|
|
adds dest2 = 16, dest
|
|
st8 [dest] = value, 8
|
|
and len = 0x7, len
|
|
(p6) br.cond.dpnt .l6 ;;
|
|
.l5:
|
|
st8 [dest] = r0, 16
|
|
st8 [dest2] = r0, 16
|
|
br.cloop.dptk .l5 ;;
|
|
.l6:
|
|
(p7) st8 [dest] = r0, 8
|
|
cmp.eq p5, p0 = len, r0
|
|
adds len = -1, len
|
|
(p5) br.cond.dptk .restore_and_exit ;;
|
|
mov ar.lc = len ;;
|
|
.l7:
|
|
st1 [dest] = r0, 1
|
|
br.cloop.dptk .l7 ;;
|
|
.restore_and_exit:
|
|
mov ar.lc = saved_lc // restore the loop counter
|
|
mov pr = saved_pr, -1 // restore the predicate registers
|
|
br.ret.sptk.many b0
|
|
|
|
.short_len:
|
|
cmp.eq p5, p0 = in2, r0
|
|
adds loopcnt = -1, in2
|
|
(p5) br.cond.spnt .restore_and_exit ;;
|
|
mov ar.lc = loopcnt // p6 should be set when we get here
|
|
.l8:
|
|
(p6) ld1 c = [in1], 1 // c = *src++
|
|
;;
|
|
st1 [in0] = c, 1 // *dest++ = c
|
|
(p6) cmp.ne p6, p0 = c, r0
|
|
br.cloop.dptk .l8
|
|
;;
|
|
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 c = 8, len
|
|
add tmp = -8, asrc ;;
|
|
cmp.gtu p8, p5 = c, thresh ;;
|
|
(p8) ld8 r[0] = [tmp]
|
|
(p5) mov r[0] = r0
|
|
br.cond.sptk .back2
|
|
.recovery3:
|
|
add tmp = -(MEMLAT + 1) * 8, src ;;
|
|
ld8 r[MEMLAT] = [tmp]
|
|
br.cond.sptk .back3
|
|
.recovery4:
|
|
cmp.eq p5, p6 = len, r0
|
|
add tmp = -MEMLAT * 8, src ;;
|
|
(p6) ld8 r[MEMLAT - 1] = [tmp]
|
|
(p5) mov r[MEMLAT - 1] = r0
|
|
br.cond.sptk .back4
|
|
END(strncpy)
|
|
libc_hidden_builtin_def (strncpy)
|