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04277e02d7
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
95 lines
2.3 KiB
ArmAsm
95 lines
2.3 KiB
ArmAsm
/* Copyright (C) 1996-2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Richard Henderson <rth@tamu.edu>, 1996.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library. If not, see
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<http://www.gnu.org/licenses/>. */
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/* Append no more than COUNT characters from the null-terminated string SRC
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to the null-terminated string DST. Always null-terminate the new DST. */
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#include <sysdep.h>
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.text
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ENTRY(strncat)
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ldgp gp, 0(pv)
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#ifdef PROF
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.set noat
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lda AT, _mcount
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jsr AT, (AT), _mcount
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.set at
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#endif
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.prologue 1
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mov a0, v0 # set up return value
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beq a2, $zerocount
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/* Find the end of the string. */
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ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned)
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lda t1, -1(zero)
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insqh t1, a0, t1
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andnot a0, 7, a0
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or t1, t0, t0
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cmpbge zero, t0, t1 # t1 <- bitmask: bit i == 1 <==> i-th byte == 0
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bne t1, $found
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$loop: ldq t0, 8(a0)
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addq a0, 8, a0 # addr += 8
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cmpbge zero, t0, t1
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beq t1, $loop
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$found: negq t1, t2 # clear all but least set bit
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and t1, t2, t1
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and t1, 0xf0, t2 # binary search for that set bit
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and t1, 0xcc, t3
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and t1, 0xaa, t4
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cmovne t2, 4, t2
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cmovne t3, 2, t3
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cmovne t4, 1, t4
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addq t2, t3, t2
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addq a0, t4, a0
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addq a0, t2, a0
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/* Now do the append. */
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jsr t9, __stxncpy
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/* Worry about the null termination. */
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zapnot t0, t8, t1 # was last byte a null?
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bne t1, 0f
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ret
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0: and t10, 0x80, t1
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bne t1, 1f
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/* Here there are bytes left in the current word. Clear one. */
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addq t10, t10, t10 # end-of-count bit <<= 1
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zap t0, t10, t0
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stq_u t0, 0(a0)
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ret
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1: /* Here we must read the next DST word and clear the first byte. */
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ldq_u t0, 8(a0)
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zap t0, 1, t0
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stq_u t0, 8(a0)
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$zerocount:
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ret
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END(strncat)
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