[thirdparty/glibc.git] / sysdeps / i386 / strpbrk.S

/* strcspn (str, ss) -- Return the length of the initial segement of STR
			which contains no characters from SS.
   For Intel 80x86, x>=3.
   Copyright (C) 1994-1997, 2000, 2003 Free Software Foundation, Inc.
   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>
   Bug fixes by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au>
   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>
#include "asm-syntax.h"
#include "bp-sym.h"
#include "bp-asm.h"

#define PARMS	LINKAGE		/* no space for saved regs */
#define RTN	PARMS
#define STR	RTN+RTN_SIZE
#define STOP	STR+PTR_SIZE

	.text
ENTRY (BP_SYM (strpbrk))
	ENTER

	movl STR(%esp), %edx
	movl STOP(%esp), %eax
	CHECK_BOUNDS_LOW (%edx, STR(%esp))

	/* First we create a table with flags for all possible characters.
	   For the ASCII (7bit/8bit) or ISO-8859-X character sets which are
	   supported by the C string functions we have 256 characters.
	   Before inserting marks for the stop characters we clear the whole
	   table.  The unrolled form is much faster than a loop.  */
	xorl %ecx, %ecx		/* %ecx = 0 !!! */

	pushl %ecx		/* make a 256 bytes long block filled with 0 */
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl %ecx
	pushl $0		/* These immediate values make the label 2 */
	pushl $0		/* to be aligned on a 16 byte boundary to */
	pushl $0		/* get a better performance of the loop.  */
	pushl $0
	pushl $0
	pushl $0

/* For understanding the following code remember that %ecx == 0 now.
   Although all the following instruction only modify %cl we always
   have a correct zero-extended 32-bit value in %ecx.  */

/* Don't change the "testb $0xff,%%cl" to "testb %%cl,%%cl".  We want
   longer instructions so that the next loop aligns without adding nops.  */

L(2):	movb (%eax), %cl	/* get byte from stopset */
	testb %cl, %cl		/* is NUL char? */
	jz L(1)			/* yes => start compare loop */
	movb %cl, (%esp,%ecx)	/* set corresponding byte in stopset table */

	movb 1(%eax), %cl	/* get byte from stopset */
	testb $0xff, %cl	/* is NUL char? */
	jz L(1)			/* yes => start compare loop */
	movb %cl, (%esp,%ecx)	/* set corresponding byte in stopset table */

	movb 2(%eax), %cl	/* get byte from stopset */
	testb $0xff, %cl	/* is NUL char? */
	jz L(1)			/* yes => start compare loop */
	movb %cl, (%esp,%ecx)	/* set corresponding byte in stopset table */

	movb 3(%eax), %cl	/* get byte from stopset */
	addl $4, %eax		/* increment stopset pointer */
	movb %cl, (%esp,%ecx)	/* set corresponding byte in stopset table */
	testb $0xff, %cl	/* is NUL char? */
	jnz L(2)		/* no => process next dword from stopset */

L(1):	leal -4(%edx), %eax	/* prepare loop */

	/* We use a neat trick for the following loop.  Normally we would
	   have to test for two termination conditions
	   1. a character in the stopset was found
	   and
	   2. the end of the string was found
	   But as a sign that the chracter is in the stopset we store its
	   value in the table.  But the value of NUL is NUL so the loop
	   terminates for NUL in every case.  */

L(3):	addl $4, %eax		/* adjust pointer for full loop round */

	movb (%eax), %cl	/* get byte from string */
	cmpb %cl, (%esp,%ecx)	/* is it contained in stopset? */
	je L(4)			/* yes => return */

	movb 1(%eax), %cl	/* get byte from string */
	cmpb %cl, (%esp,%ecx)	/* is it contained in stopset? */
	je L(5)			/* yes => return */

	movb 2(%eax), %cl	/* get byte from string */
	cmpb %cl, (%esp,%ecx)	/* is it contained in stopset? */
	je L(6)			/* yes => return */

	movb 3(%eax), %cl	/* get byte from string */
	cmpb %cl, (%esp,%ecx)	/* is it contained in stopset? */
	jne L(3)			/* yes => return */

	incl %eax		/* adjust pointer */
L(6):	incl %eax
L(5):	incl %eax

L(4):	addl $256, %esp		/* remove stopset */

	CHECK_BOUNDS_HIGH (%eax, STR(%esp), jb)
	orb %cl, %cl		/* was last character NUL? */
	jnz L(7)		/* no => return pointer */
	xorl %eax, %eax
	RETURN_NULL_BOUNDED_POINTER

	LEAVE
	RET_PTR

L(7):	RETURN_BOUNDED_POINTER (STR(%esp))

	LEAVE
	RET_PTR
END (BP_SYM (strpbrk))
libc_hidden_builtin_def (strpbrk)
Commit	Line	Data
8f5ca04b RM	1	/* strcspn (str, ss) -- Return the length of the initial segement of STR
8f5ca04b RM	2	which contains no characters from SS.
5929563f	3	For Intel 80x86, x>=3.
a334319f	4	Copyright (C) 1994-1997, 2000, 2003 Free Software Foundation, Inc.
5929563f UD	5	Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>
	6	Bug fixes by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au>
	7	This file is part of the GNU C Library.
	8
	9	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	10	modify it under the terms of the GNU Lesser General Public
	11	License as published by the Free Software Foundation; either
	12	version 2.1 of the License, or (at your option) any later version.
5929563f UD	13
	14	The GNU C Library is distributed in the hope that it will be useful,
	15	but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41bdb6e2	17	Lesser General Public License for more details.
5929563f	18
41bdb6e2 AJ	19	You should have received a copy of the GNU Lesser General Public
	20	License along with the GNU C Library; if not, write to the Free
	21	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	22	02111-1307 USA. */
8f5ca04b RM	23
	24	#include <sysdep.h>
	25	#include "asm-syntax.h"
2fc08826	26	#include "bp-sym.h"
3f02f778	27	#include "bp-asm.h"
8f5ca04b	28
3f02f778 GM	29	#define PARMS LINKAGE /* no space for saved regs */
	30	#define RTN PARMS
	31	#define STR RTN+RTN_SIZE
	32	#define STOP STR+PTR_SIZE
8f5ca04b RM	33
8f5ca04b RM	34	.text
2fc08826	35	ENTRY (BP_SYM (strpbrk))
3f02f778 GM	36	ENTER
	37
	38	movl STR(%esp), %edx
	39	movl STOP(%esp), %eax
2fc08826	40	CHECK_BOUNDS_LOW (%edx, STR(%esp))
8f5ca04b RM	41
	42	/* First we create a table with flags for all possible characters.
	43	For the ASCII (7bit/8bit) or ISO-8859-X character sets which are
	44	supported by the C string functions we have 256 characters.
	45	Before inserting marks for the stop characters we clear the whole
	46	table. The unrolled form is much faster than a loop. */
	47	xorl %ecx, %ecx /* %ecx = 0 !!! */
	48
	49	pushl %ecx /* make a 256 bytes long block filled with 0 */
	50	pushl %ecx
	51	pushl %ecx
	52	pushl %ecx
	53	pushl %ecx
	54	pushl %ecx
	55	pushl %ecx
	56	pushl %ecx
	57	pushl %ecx
	58	pushl %ecx
	59	pushl %ecx
	60	pushl %ecx
	61	pushl %ecx
	62	pushl %ecx
	63	pushl %ecx
	64	pushl %ecx
	65	pushl %ecx
	66	pushl %ecx
	67	pushl %ecx
	68	pushl %ecx
	69	pushl %ecx
	70	pushl %ecx
	71	pushl %ecx
	72	pushl %ecx
	73	pushl %ecx
	74	pushl %ecx
	75	pushl %ecx
	76	pushl %ecx
	77	pushl %ecx
	78	pushl %ecx
	79	pushl %ecx
	80	pushl %ecx
	81	pushl %ecx
	82	pushl %ecx
	83	pushl %ecx
	84	pushl %ecx
	85	pushl %ecx
	86	pushl %ecx
	87	pushl %ecx
	88	pushl %ecx
	89	pushl %ecx
	90	pushl %ecx
	91	pushl %ecx
	92	pushl %ecx
	93	pushl %ecx
	94	pushl %ecx
	95	pushl %ecx
	96	pushl %ecx
	97	pushl %ecx
	98	pushl %ecx
	99	pushl %ecx
	100	pushl %ecx
	101	pushl %ecx
	102	pushl %ecx
	103	pushl %ecx
	104	pushl %ecx
105	pushl %ecx
106	pushl %ecx
107	pushl $0 /* These immediate values make the label 2 */
108	pushl $0 /* to be aligned on a 16 byte boundary to */
109	pushl $0 /* get a better performance of the loop. */
110	pushl $0
111	pushl $0
112	pushl $0
113
114	/* For understanding the following code remember that %ecx == 0 now.
115	Although all the following instruction only modify %cl we always
116	have a correct zero-extended 32-bit value in %ecx. */
117
118	/* Don't change the "testb $0xff,%%cl" to "testb %%cl,%%cl". We want
119	longer instructions so that the next loop aligns without adding nops. */
120
5929563f	121	L(2): movb (%eax), %cl /* get byte from stopset */
8f5ca04b	122	testb %cl, %cl /* is NUL char? */
5929563f	123	jz L(1) /* yes => start compare loop */
8f5ca04b RM	124	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	125
	126	movb 1(%eax), %cl /* get byte from stopset */
	127	testb $0xff, %cl /* is NUL char? */
5929563f	128	jz L(1) /* yes => start compare loop */
8f5ca04b RM	129	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	130
	131	movb 2(%eax), %cl /* get byte from stopset */
	132	testb $0xff, %cl /* is NUL char? */
5929563f	133	jz L(1) /* yes => start compare loop */
8f5ca04b RM	134	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	135
	136	movb 3(%eax), %cl /* get byte from stopset */
	137	addl $4, %eax /* increment stopset pointer */
	138	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	139	testb $0xff, %cl /* is NUL char? */
5929563f	140	jnz L(2) /* no => process next dword from stopset */
8f5ca04b	141
5929563f	142	L(1): leal -4(%edx), %eax /* prepare loop */
8f5ca04b RM	143
	144	/* We use a neat trick for the following loop. Normally we would
	145	have to test for two termination conditions
	146	1. a character in the stopset was found
	147	and
	148	2. the end of the string was found
	149	But as a sign that the chracter is in the stopset we store its
	150	value in the table. But the value of NUL is NUL so the loop
	151	terminates for NUL in every case. */
	152
5929563f	153	L(3): addl $4, %eax /* adjust pointer for full loop round */
8f5ca04b RM	154
	155	movb (%eax), %cl /* get byte from string */
	156	cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
5929563f	157	je L(4) /* yes => return */
8f5ca04b RM	158
	159	movb 1(%eax), %cl /* get byte from string */
	160	cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
5929563f	161	je L(5) /* yes => return */
8f5ca04b RM	162
	163	movb 2(%eax), %cl /* get byte from string */
	164	cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
5929563f	165	je L(6) /* yes => return */
8f5ca04b RM	166
	167	movb 3(%eax), %cl /* get byte from string */
	168	cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
5929563f	169	jne L(3) /* yes => return */
8f5ca04b RM	170
8f5ca04b RM	171	incl %eax /* adjust pointer */
5929563f UD	172	L(6): incl %eax
5929563f UD	173	L(5): incl %eax
8f5ca04b	174
5929563f	175	L(4): addl $256, %esp /* remove stopset */
8f5ca04b	176
2fc08826	177	CHECK_BOUNDS_HIGH (%eax, STR(%esp), jb)
8f5ca04b	178	orb %cl, %cl /* was last character NUL? */
2fc08826 GM	179	jnz L(7) /* no => return pointer */
	180	xorl %eax, %eax
	181	RETURN_NULL_BOUNDED_POINTER
8f5ca04b	182
2fc08826	183	LEAVE
3f02f778	184	RET_PTR
2fc08826 GM	185
	186	L(7): RETURN_BOUNDED_POINTER (STR(%esp))
	187
	188	LEAVE
	189	RET_PTR
	190	END (BP_SYM (strpbrk))
85dd1003	191	libc_hidden_builtin_def (strpbrk)