Alpha ev67 strlen implementation.

diff --git a/sysdeps/alpha/alphaev67/strlen.S b/sysdeps/alpha/alphaev67/strlen.S
new file mode 100644 (file)
index 0000000..ac8740f
--- /dev/null
+++ b/sysdeps/alpha/alphaev67/strlen.S
@@ -0,0 +1,61 @@
+/* Copyright (C) 2000 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* 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)