summaryrefslogtreecommitdiff
path: root/ports/sysdeps/alpha/strncpy.S
diff options
context:
space:
mode:
Diffstat (limited to 'ports/sysdeps/alpha/strncpy.S')
-rw-r--r--ports/sysdeps/alpha/strncpy.S87
1 files changed, 87 insertions, 0 deletions
diff --git a/ports/sysdeps/alpha/strncpy.S b/ports/sysdeps/alpha/strncpy.S
new file mode 100644
index 0000000000..c370e0850b
--- /dev/null
+++ b/ports/sysdeps/alpha/strncpy.S
@@ -0,0 +1,87 @@
+/* Copyright (C) 1996, 1997, 2003 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 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/>. */
+
+/* Copy no more than COUNT bytes of the null-terminated string from
+ SRC to DST. If SRC does not cover all of COUNT, the balance is
+ zeroed. */
+
+#include <sysdep.h>
+
+ .set noat
+ .set noreorder
+
+ .text
+
+ENTRY(strncpy)
+ ldgp gp, 0(pv)
+#ifdef PROF
+ lda AT, _mcount
+ jsr AT, (AT), _mcount
+#endif
+ .prologue 1
+
+ mov a0, v0 # set return value now
+ beq a2, $zerocount
+ jsr t9, __stxncpy # do the work of the copy
+
+ bne a2, $multiword # do we have full words left?
+
+ .align 3
+ subq t8, 1, t2 # e0 : guess not
+ subq t10, 1, t3 # .. e1 :
+ or t2, t8, t2 # e0 : clear the bits between the last
+ or t3, t10, t3 # .. e1 : written byte and the last byte in
+ andnot t3, t2, t3 # e0 : COUNT
+ zap t0, t3, t0 # e1 :
+ stq_u t0, 0(a0) # e0 :
+ ret # .. e1 :
+
+$multiword:
+ subq t8, 1, t7 # e0 : clear the final bits in the prev
+ or t7, t8, t7 # e1 : word
+ zapnot t0, t7, t0 # e0 :
+ subq a2, 1, a2 # .. e1 :
+ stq_u t0, 0(a0) # e0 :
+ addq a0, 8, a0 # .. e1 :
+
+ beq a2, 1f # e1 :
+ blbc a2, 0f # e1 :
+
+ stq_u zero, 0(a0) # e0 : zero one word
+ subq a2, 1, a2 # .. e1 :
+ addq a0, 8, a0 # e0 :
+ beq a2, 1f # .. e1 :
+
+0: stq_u zero, 0(a0) # e0 : zero two words
+ subq a2, 2, a2 # .. e1 :
+ stq_u zero, 8(a0) # e0 :
+ addq a0, 16, a0 # .. e1 :
+ bne a2, 0b # e1 :
+ unop
+
+1: ldq_u t0, 0(a0) # e0 : clear the leading bits in the final
+ subq t10, 1, t7 # .. e1 : word
+ or t7, t10, t7 # e0 :
+ zap t0, t7, t0 # e1 (stall)
+ stq_u t0, 0(a0) # e0 :
+
+$zerocount:
+ ret # .. e1 :
+
+ END(strncpy)
+libc_hidden_builtin_def (strncpy)