xref: /onnv-gate/usr/src/lib/libc/amd64/gen/wsncmp.s (revision 7298:b69e27387f74)
10Sstevel@tonic-gate/*
20Sstevel@tonic-gate * CDDL HEADER START
30Sstevel@tonic-gate *
40Sstevel@tonic-gate * The contents of this file are subject to the terms of the
56812Sraf * Common Development and Distribution License (the "License").
66812Sraf * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate *
80Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate * See the License for the specific language governing permissions
110Sstevel@tonic-gate * and limitations under the License.
120Sstevel@tonic-gate *
130Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
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180Sstevel@tonic-gate *
190Sstevel@tonic-gate * CDDL HEADER END
200Sstevel@tonic-gate */
216812Sraf
220Sstevel@tonic-gate/*
236812Sraf * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
240Sstevel@tonic-gate * Use is subject to license terms.
250Sstevel@tonic-gate */
260Sstevel@tonic-gate
27*7298SMark.J.Nelson@Sun.COM	.file	"wsncmp.s"
280Sstevel@tonic-gate
290Sstevel@tonic-gate/
300Sstevel@tonic-gate/ Wide character wcsncpy() implementation
310Sstevel@tonic-gate/
320Sstevel@tonic-gate/ Algorithm based on Solaris 2.6 gen/strncpy.s implementation
330Sstevel@tonic-gate/
340Sstevel@tonic-gate
350Sstevel@tonic-gate#include <sys/asm_linkage.h>
360Sstevel@tonic-gate
370Sstevel@tonic-gate	ANSI_PRAGMA_WEAK(wcsncmp,function)
380Sstevel@tonic-gate	ANSI_PRAGMA_WEAK(wsncmp,function)
390Sstevel@tonic-gate
406812Sraf	ENTRY(wcsncmp)		/* (wchar *ws1, wchar_t *ws2, size_t n) */
410Sstevel@tonic-gate	cmpq	%rdi,%rsi	/ same string?
420Sstevel@tonic-gate	je	.equal
430Sstevel@tonic-gate	incq	%rdx		/ will later predecrement this uint
440Sstevel@tonic-gate.loop:
450Sstevel@tonic-gate	decq	%rdx
460Sstevel@tonic-gate	je	.equal		/ Used all n chars?
470Sstevel@tonic-gate	movl	(%rdi),%eax	/ slodb ; scab
480Sstevel@tonic-gate	cmpl	(%rsi),%eax
490Sstevel@tonic-gate	jne	.notequal_0	/ Are the bytes equal?
500Sstevel@tonic-gate	testl	%eax,%eax
510Sstevel@tonic-gate	je	.equal		/ End of string?
520Sstevel@tonic-gate
530Sstevel@tonic-gate	decq	%rdx
540Sstevel@tonic-gate	je	.equal		/ Used all n chars?
550Sstevel@tonic-gate	movl	4(%rdi),%eax	/ slodb ; scab
560Sstevel@tonic-gate	cmpl	4(%rsi),%eax
570Sstevel@tonic-gate	jne	.notequal_1	/ Are the bytes equal?
580Sstevel@tonic-gate	testl	%eax,%eax
590Sstevel@tonic-gate	je	.equal		/ End of string?
600Sstevel@tonic-gate
610Sstevel@tonic-gate	decq	%rdx
620Sstevel@tonic-gate	je	.equal		/ Used all n chars?
630Sstevel@tonic-gate	movl	8(%rdi),%eax	/ slodb ; scab
640Sstevel@tonic-gate	cmpl	8(%rsi),%eax
650Sstevel@tonic-gate	jne	.notequal_2	/ Are the bytes equal?
660Sstevel@tonic-gate	testl	%eax,%eax
670Sstevel@tonic-gate	je	.equal		/ End of string?
680Sstevel@tonic-gate
690Sstevel@tonic-gate	decq	%rdx
700Sstevel@tonic-gate	je	.equal		/ Used all n chars?
710Sstevel@tonic-gate	movl	12(%rdi),%eax	/ slodb ; scab
720Sstevel@tonic-gate	cmpl	12(%rsi),%eax
730Sstevel@tonic-gate	jne	.notequal_3	/ Are the bytes equal?
740Sstevel@tonic-gate	addq	$16,%rdi
750Sstevel@tonic-gate	addq	$16,%rsi
760Sstevel@tonic-gate	testl	%eax,%eax
770Sstevel@tonic-gate	jne	.loop		/ End of string?
780Sstevel@tonic-gate
790Sstevel@tonic-gate.equal:
800Sstevel@tonic-gate	xorl	%eax,%eax	/ return 0
810Sstevel@tonic-gate	ret
820Sstevel@tonic-gate
830Sstevel@tonic-gate	.align	4
840Sstevel@tonic-gate.notequal_3:
850Sstevel@tonic-gate	addq	$4,%rsi
860Sstevel@tonic-gate.notequal_2:
870Sstevel@tonic-gate	addq	$4,%rsi
880Sstevel@tonic-gate.notequal_1:
890Sstevel@tonic-gate	addq	$4,%rsi
900Sstevel@tonic-gate.notequal_0:
910Sstevel@tonic-gate	subl	(%rsi),%eax	/ return value is (*s1 - *--s2)
920Sstevel@tonic-gate	ret
936812Sraf	SET_SIZE(wcsncmp)
940Sstevel@tonic-gate
956812Sraf	ENTRY(wsncmp)
966812Sraf	jmp	wcsncmp		/ tail call into wcsncmp
976812Sraf	SET_SIZE(wsncmp)
98