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-rw-r--r--sysdeps/s390/strncpy.S79
1 files changed, 79 insertions, 0 deletions
diff --git a/sysdeps/s390/strncpy.S b/sysdeps/s390/strncpy.S
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+++ b/sysdeps/s390/strncpy.S
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+/* strncpy - copy at most n characters from a string from source to
+   destination.  For IBM S390
+   This file is part of the GNU C Library.
+   Copyright (C) 2000 Free Software Foundation, Inc.
+   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
+
+   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.  */
+
+/*
+ * R2 = address of destination (dst)
+ * R3 = address of source (src)
+ * R4 = max of bytes to copy
+ */
+
+#include "sysdep.h"
+#include "asm-syntax.h"
+
+ENTRY(strncpy)
+	.text
+	st    %r2,24(%r15)          # save dst pointer
+	slr   %r2,%r3               # %r3 points to src, %r2+%r3 to dst
+	lhi   %r1,3
+	nr    %r1,%r4               # last 2 bits of # bytes
+	srl   %r4,2
+	ltr   %r4,%r4               # less than 4 bytes to copy ?
+	jz    .L1
+	bras  %r5,.L0               # enter loop & load address of a 0
+	.long 0
+.L0:    icm   %r0,8,0(%r3)          # first byte
+	jz    .L3
+	icm   %r0,4,1(%r3)          # second byte
+	jz    .L4
+	icm   %r0,2,2(%r3)          # third byte
+	jz    .L5
+	icm   %r0,1,3(%r3)          # fourth byte
+	jz    .L6
+	st    %r0,0(%r2,%r3)        # store all four to dest.
+	la    %r3,4(%r3)
+	brct  %r4,.L0
+.L1:    ltr   %r1,%r1
+	jz    .Lexit
+.L2:    icm   %r0,1,0(%r3)
+	stc   %r0,0(%r2,%r3)
+	la    %r3,1(%r3)
+	jz    .L7
+	brct  %r1,.L2
+	j     .Lexit
+.L3:    icm   %r0,4,0(%r5)
+.L4:    icm   %r0,2,0(%r5)
+.L5:    icm   %r0,1,0(%r5)
+.L6:    st    %r0,0(%r2,%r3)
+	la    %r3,4(%r3)
+	ahi   %r4,-1
+	j     .L8
+.L7:    ahi   %r1,-1
+.L8:    sll   %r4,2
+	alr   %r4,%r1
+	alr   %r2,%r3               # start of dst area to be zeroed
+	lr    %r3,%r4
+	slr   %r4,%r4
+	slr   %r5,%r5
+.L9:    mvcle %r2,%r4,0             # pad dst with zeroes
+	jo    .L9
+.Lexit: l     %r2,24(%r15)          # return dst pointer
+	br    %r14
+END(strncpy)