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/* Optimized version of the memccpy() function.
This file is part of the GNU C Library.
Copyright (C) 2000-2021 Free Software Foundation, Inc.
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
<https://www.gnu.org/licenses/>. */
/* Return: a pointer to the next byte after char in dest or NULL
Inputs:
in0: dest
in1: src
in2: char
in3: byte count
This implementation assumes little endian mode (UM.be = 0).
This implementation assumes that it is safe to do read ahead
in the src block, without getting beyond its limit. */
#include <sysdep.h>
#undef ret
#define OP_T_THRES 16
#define OPSIZ 8
#define saved_pr r17
#define saved_lc r18
#define dest r19
#define src r20
#define len r21
#define asrc r22
#define tmp r23
#define char r24
#define charx8 r25
#define saved_ec r26
#define sh2 r28
#define sh1 r29
#define loopcnt r30
#define value r31
#ifdef GAS_ALIGN_BREAKS_UNWIND_INFO
/* Manually force proper loop-alignment. Note: be sure to
double-check the code-layout after making any changes to
this routine! */
# define ALIGN(n) { nop 0 }
#else
# define ALIGN(n) .align n
#endif
ENTRY(memccpy)
.prologue
alloc r2 = ar.pfs, 4, 40 - 4, 0, 40
#include "softpipe.h"
.rotr r[MEMLAT + 7], tmp1[4], tmp2[4], val[4], tmp3[2], pos0[2]
.rotp p[MEMLAT + 6 + 1]
mov ret0 = r0 // return NULL if no match
.save pr, saved_pr
mov saved_pr = pr // save the predicate registers
mov dest = in0 // dest
.save ar.lc, saved_lc
mov saved_lc = ar.lc // save the loop counter
mov saved_ec = ar.ec // save the loop counter
.body
mov src = in1 // src
extr.u char = in2, 0, 8 // char
mov len = in3 // len
sub tmp = r0, in0 // tmp = -dest
cmp.ne p7, p0 = r0, r0 // clear p7
;;
and loopcnt = 7, tmp // loopcnt = -dest % 8
cmp.ge p6, p0 = OP_T_THRES, len // is len <= OP_T_THRES
mov ar.ec = 0 // ec not guaranteed zero on entry
(p6) br.cond.spnt .cpyfew // copy byte by byte
;;
cmp.eq p6, p0 = loopcnt, r0
mux1 charx8 = char, @brcst
(p6) br.cond.sptk .dest_aligned
sub len = len, loopcnt // len -= -dest % 8
adds loopcnt = -1, loopcnt // --loopcnt
;;
mov ar.lc = loopcnt
.l1: // copy -dest % 8 bytes
ld1 value = [src], 1 // value = *src++
;;
st1 [dest] = value, 1 // *dest++ = value
cmp.eq p6, p0 = value, char
(p6) br.cond.spnt .foundit
br.cloop.dptk .l1
.dest_aligned:
and sh1 = 7, src // sh1 = src % 8
and tmp = -8, len // tmp = len & -OPSIZ
and asrc = -8, src // asrc = src & -OPSIZ -- align src
shr.u loopcnt = len, 3 // loopcnt = len / 8
and len = 7, len ;; // len = len % 8
shl sh1 = sh1, 3 // sh1 = 8 * (src % 8)
adds loopcnt = -1, loopcnt // --loopcnt
mov pr.rot = 1 << 16 ;; // set rotating predicates
sub sh2 = 64, sh1 // sh2 = 64 - sh1
mov ar.lc = loopcnt // set LC
cmp.eq p6, p0 = sh1, r0 // is the src aligned?
(p6) br.cond.sptk .src_aligned ;;
add src = src, tmp // src += len & -OPSIZ
mov ar.ec = MEMLAT + 6 + 1 // six more passes needed
ld8 r[1] = [asrc], 8 // r[1] = w0
cmp.ne p6, p0 = r0, r0 ;; // clear p6
ALIGN(32)
.l2:
(p[0]) ld8.s r[0] = [asrc], 8 // r[0] = w1
(p[MEMLAT]) shr.u tmp1[0] = r[1 + MEMLAT], sh1 // tmp1 = w0 >> sh1
(p[MEMLAT]) shl tmp2[0] = r[0 + MEMLAT], sh2 // tmp2 = w1 << sh2
(p[MEMLAT+4]) xor tmp3[0] = val[1], charx8
(p[MEMLAT+5]) czx1.r pos0[0] = tmp3[1]
(p[MEMLAT+6]) chk.s r[6 + MEMLAT], .recovery1 // our data isn't
// valid - rollback!
(p[MEMLAT+6]) cmp.ne p6, p0 = 8, pos0[1]
(p6) br.cond.spnt .gotit
(p[MEMLAT+6]) st8 [dest] = val[3], 8 // store val to dest
(p[MEMLAT+3]) or val[0] = tmp1[3], tmp2[3] // val = tmp1 | tmp2
br.ctop.sptk .l2
br.cond.sptk .cpyfew
.src_aligned:
cmp.ne p6, p0 = r0, r0 // clear p6
mov ar.ec = MEMLAT + 2 + 1 ;; // set EC
.l3:
(p[0]) ld8.s r[0] = [src], 8
(p[MEMLAT]) xor tmp3[0] = r[MEMLAT], charx8
(p[MEMLAT+1]) czx1.r pos0[0] = tmp3[1]
(p[MEMLAT+2]) cmp.ne p7, p0 = 8, pos0[1]
(p[MEMLAT+2]) chk.s r[MEMLAT+2], .recovery2
(p7) br.cond.spnt .gotit
.back2:
(p[MEMLAT+2]) st8 [dest] = r[MEMLAT+2], 8
br.ctop.dptk .l3
.cpyfew:
cmp.eq p6, p0 = len, r0 // is len == 0 ?
adds len = -1, len // --len;
(p6) br.cond.spnt .restore_and_exit ;;
mov ar.lc = len
.l4:
ld1 value = [src], 1
;;
st1 [dest] = value, 1
cmp.eq p6, p0 = value, char
(p6) br.cond.spnt .foundit
br.cloop.dptk .l4 ;;
.foundit:
(p6) mov ret0 = dest
.restore_and_exit:
mov pr = saved_pr, -1 // restore the predicate registers
mov ar.lc = saved_lc // restore the loop counter
mov ar.ec = saved_ec ;; // restore the epilog counter
br.ret.sptk.many b0
.gotit:
.pred.rel "mutex" p6, p7
(p6) mov value = val[3] // if coming from l2
(p7) mov value = r[MEMLAT+2] // if coming from l3
mov ar.lc = pos0[1] ;;
.l5:
extr.u tmp = value, 0, 8 ;;
st1 [dest] = tmp, 1
shr.u value = value, 8
br.cloop.sptk .l5 ;;
mov ret0 = dest
mov pr = saved_pr, -1
mov ar.lc = saved_lc
br.ret.sptk.many b0
.recovery1:
#if MEMLAT != 6
# error "MEMLAT must be 6!"
#endif
adds src = -8, asrc
mov loopcnt = ar.lc
mov tmp = ar.ec
;;
(p[0]) adds src = -8, src
;;
(p[1]) adds src = -8, src
sub sh1 = (MEMLAT + 6 + 1), tmp
;;
(p[2]) adds src = -8, src
;;
(p[3]) adds src = -8, src
shl loopcnt = loopcnt, 3
;;
(p[4]) adds src = -8, src
;;
(p[5]) adds src = -8, src
shl sh1 = sh1, 3
;;
(p[6]) adds src = -8, src
;;
(p[7]) adds src = -8, src
shl tmp = tmp, 3
;;
(p[8]) adds src = -8, src
;;
(p[9]) adds src = -8, src
shr.u sh2 = sh2, 3
;;
(p[10]) adds src = -8, src
;;
(p[11]) adds src = -8, src
add len = len, loopcnt
;;
sub src = src, sh2
;;
add len = tmp, len
add src = sh1, src
br.cond.sptk .cpyfew
.recovery2:
#if MEMLAT != 6
# error "MEMLAT must be 6!"
#endif
add tmp = -8, src
(p7) br.cond.spnt .gotit
;;
(p[0]) add tmp = -8, tmp ;;
(p[1]) add tmp = -8, tmp ;;
(p[2]) add tmp = -8, tmp ;;
(p[3]) add tmp = -8, tmp ;;
(p[4]) add tmp = -8, tmp ;;
(p[5]) add tmp = -8, tmp ;;
(p[6]) add tmp = -8, tmp ;;
(p[7]) add tmp = -8, tmp ;;
ld8 r[MEMLAT+2] = [tmp] ;;
xor pos0[1] = r[MEMLAT+2], charx8 ;;
czx1.r pos0[1] = pos0[1] ;;
cmp.ne p7, p6 = 8, pos0[1]
(p7) br.cond.spnt .gotit
br.cond.sptk .back2
END(memccpy)
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