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Diffstat (limited to 'ports/sysdeps/alpha/strncat.S')
| -rw-r--r-- | ports/sysdeps/alpha/strncat.S | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/ports/sysdeps/alpha/strncat.S b/ports/sysdeps/alpha/strncat.S new file mode 100644 index 0000000000..832a3ed506 --- /dev/null +++ b/ports/sysdeps/alpha/strncat.S @@ -0,0 +1,94 @@ +/* Copyright (C) 1996 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Richard Henderson <rth@tamu.edu>, 1996. + + 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 + <http://www.gnu.org/licenses/>. */ + +/* Append no more than COUNT characters from the null-terminated string SRC + to the null-terminated string DST. Always null-terminate the new DST. */ + +#include <sysdep.h> + + .text + +ENTRY(strncat) + ldgp gp, 0(pv) +#ifdef PROF + .set noat + lda AT, _mcount + jsr AT, (AT), _mcount + .set at +#endif + .prologue 1 + + mov a0, v0 # set up return value + beq a2, $zerocount + + /* Find the end of the string. */ + + ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned) + lda t1, -1(zero) + insqh t1, a0, t1 + andnot a0, 7, a0 + or t1, t0, t0 + cmpbge zero, t0, t1 # t1 <- bitmask: bit i == 1 <==> i-th byte == 0 + bne t1, $found + +$loop: ldq t0, 8(a0) + addq a0, 8, a0 # addr += 8 + cmpbge zero, t0, t1 + beq t1, $loop + +$found: negq t1, t2 # clear all but least set bit + and t1, t2, t1 + + and t1, 0xf0, t2 # binary search for that set bit + and t1, 0xcc, t3 + and t1, 0xaa, t4 + cmovne t2, 4, t2 + cmovne t3, 2, t3 + cmovne t4, 1, t4 + addq t2, t3, t2 + addq a0, t4, a0 + addq a0, t2, a0 + + /* Now do the append. */ + + jsr t9, __stxncpy + + /* Worry about the null termination. */ + + zapnot t0, t8, t1 # was last byte a null? + bne t1, 0f + ret + +0: and t10, 0x80, t1 + bne t1, 1f + + /* Here there are bytes left in the current word. Clear one. */ + addq t10, t10, t10 # end-of-count bit <<= 1 + zap t0, t10, t0 + stq_u t0, 0(a0) + ret + +1: /* Here we must read the next DST word and clear the first byte. */ + ldq_u t0, 8(a0) + zap t0, 1, t0 + stq_u t0, 8(a0) + +$zerocount: + ret + + END(strncat) |