about summary refs log tree commit diff
path: root/sysdeps/alpha/strcat.S
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/alpha/strcat.S')
-rw-r--r--sysdeps/alpha/strcat.S66
1 files changed, 66 insertions, 0 deletions
diff --git a/sysdeps/alpha/strcat.S b/sysdeps/alpha/strcat.S
new file mode 100644
index 0000000000..d3afff3c5f
--- /dev/null
+++ b/sysdeps/alpha/strcat.S
@@ -0,0 +1,66 @@
+/* Copyright (C) 1996 Free Software Foundation, Inc.
+   Contributed by Richard Henderson (rth@tamu.edu)
+
+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., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+/* Append a null-terminated string from SRC to DST.  */
+
+#include <sysdep.h>
+
+	.text
+
+ENTRY(strcat)
+	ldgp	gp, 0(pv)
+	.prologue 1
+
+	mov	a0, v0		# set up return value
+
+	/* 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, __stxcpy
+	ret
+
+	END(strcat)