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Diffstat (limited to 'sysdeps/alpha/alphaev67/strlen.S')
-rw-r--r-- | sysdeps/alpha/alphaev67/strlen.S | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/sysdeps/alpha/alphaev67/strlen.S b/sysdeps/alpha/alphaev67/strlen.S new file mode 100644 index 0000000000..22ab1bffd5 --- /dev/null +++ b/sysdeps/alpha/alphaev67/strlen.S @@ -0,0 +1,60 @@ +/* Copyright (C) 2000-2014 Free Software Foundation, Inc. + Contributed by David Mosberger (davidm@cs.arizona.edu). + EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>. + This file is part of the GNU C Library. + + 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/>. */ + +/* Finds length of a 0-terminated string. */ + +#include <sysdep.h> + + .arch ev6 + .set noreorder + .set noat + +ENTRY(strlen) +#ifdef PROF + ldgp gp, 0(pv) + lda AT, _mcount + jsr AT, (AT), _mcount + .prologue 1 +#else + .prologue 0 +#endif + + ldq_u $1, 0($16) # L : load first quadword ($16 may be misaligned) + lda $2, -1($31) # E : + insqh $2, $16, $2 # U : + andnot $16, 7, $0 # E : + + or $2, $1, $1 # E : + cmpbge $31, $1, $2 # E : $2 <- bitmask: bit i == 1 <==> i-th byte == 0 + nop # E : + bne $2, $found # U : + +$loop: ldq $1, 8($0) # L : + addq $0, 8, $0 # E : addr += 8 + cmpbge $31, $1, $2 # E : + beq $2, $loop # U : + +$found: + cttz $2, $3 # U0 : + addq $0, $3, $0 # E : + subq $0, $16, $0 # E : + ret $31, ($26) # L0 : + + END(strlen) +libc_hidden_builtin_def (strlen) |