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67 lines
1.7 KiB
ArmAsm
67 lines
1.7 KiB
ArmAsm
/* Copyright (C) 1996 Free Software Foundation, Inc.
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Contributed by Richard Henderson (rth@tamu.edu)
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This file is part of the GNU C Library.
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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 Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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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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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA. */
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/* Append a null-terminated string from SRC to DST. */
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#include <sysdep.h>
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.text
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ENTRY(strcat)
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ldgp gp, 0(pv)
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.prologue 1
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mov a0, v0 # set up return value
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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, __stxcpy
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ret
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END(strcat)
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