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

/* strcspn (str, ss) -- Return the length of the initial segment of STR
			which contains only characters from SS.
   For Intel 80x86, x>=3.
   Copyright (C) 1994-1997, 2000, 2003, 2005 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>
   Bug fixes by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au>

   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 STR	PARMS
#define SKIP	STR+PTR_SIZE

	.text
ENTRY (BP_SYM (strspn))
	ENTER

	movl STR(%esp), %edx
	movl SKIP(%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 */
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl $0		/* These immediate values make the label 2 */
	cfi_adjust_cfa_offset (4)
	pushl $0		/* to be aligned on a 16 byte boundary to */
	cfi_adjust_cfa_offset (4)
	pushl $0		/* get a better performance of the loop.  */
	cfi_adjust_cfa_offset (4)
	pushl $0
	cfi_adjust_cfa_offset (4)
	pushl $0
	cfi_adjust_cfa_offset (4)
	pushl $0
	cfi_adjust_cfa_offset (4)

/* 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 character 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 */
	testb %cl, (%esp,%ecx)	/* is it contained in skipset? */
	jz L(4)			/* no => return */

	movb 1(%eax), %cl	/* get byte from string */
	testb %cl, (%esp,%ecx)	/* is it contained in skipset? */
	jz L(5)			/* no => return */

	movb 2(%eax), %cl	/* get byte from string */
	testb %cl, (%esp,%ecx)	/* is it contained in skipset? */
	jz L(6)			/* no => return */

	movb 3(%eax), %cl	/* get byte from string */
	testb %cl, (%esp,%ecx)	/* is it contained in skipset? */
	jnz L(3)		/* yes => start loop again */

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

L(4):	addl $256, %esp		/* remove stopset */
	cfi_adjust_cfa_offset (-256)
	CHECK_BOUNDS_HIGH (%eax, STR(%esp), jb)
	subl %edx, %eax		/* we have to return the number of valid
				   characters, so compute distance to first
				   non-valid character */
	LEAVE
	ret
END (BP_SYM (strspn))
libc_hidden_builtin_def (strspn)
Commit	Line	Data
6d52618b	1	/* strcspn (str, ss) -- Return the length of the initial segment of STR
8f5ca04b	2	which contains only characters from SS.
6d52618b	3	For Intel 80x86, x>=3.
0ecb606c	4	Copyright (C) 1994-1997, 2000, 2003, 2005 Free Software Foundation, Inc.
6d52618b UD	5	This file is part of the GNU C Library.
	6	Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>
	7	Bug fixes by Alan Modra <Alan@SPRI.Levels.UniSA.Edu.Au>
	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.
6d52618b 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.
6d52618b	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 STR PARMS
	31	#define SKIP STR+PTR_SIZE
8f5ca04b RM	32
8f5ca04b RM	33	.text
2fc08826	34	ENTRY (BP_SYM (strspn))
3f02f778 GM	35	ENTER
	36
	37	movl STR(%esp), %edx
	38	movl SKIP(%esp), %eax
2fc08826	39	CHECK_BOUNDS_LOW (%edx, STR(%esp))
8f5ca04b RM	40
	41	/* First we create a table with flags for all possible characters.
	42	For the ASCII (7bit/8bit) or ISO-8859-X character sets which are
	43	supported by the C string functions we have 256 characters.
	44	Before inserting marks for the stop characters we clear the whole
	45	table. The unrolled form is much faster than a loop. */
	46	xorl %ecx, %ecx /* %ecx = 0 !!! */
	47
	48	pushl %ecx /* make a 256 bytes long block filled with 0 */
0ecb606c	49	cfi_adjust_cfa_offset (4)
8f5ca04b	50	pushl %ecx
0ecb606c	51	cfi_adjust_cfa_offset (4)
8f5ca04b	52	pushl %ecx
0ecb606c	53	cfi_adjust_cfa_offset (4)
8f5ca04b	54	pushl %ecx
0ecb606c	55	cfi_adjust_cfa_offset (4)
8f5ca04b	56	pushl %ecx
0ecb606c	57	cfi_adjust_cfa_offset (4)
8f5ca04b	58	pushl %ecx
0ecb606c	59	cfi_adjust_cfa_offset (4)
8f5ca04b	60	pushl %ecx
0ecb606c	61	cfi_adjust_cfa_offset (4)
8f5ca04b	62	pushl %ecx
0ecb606c	63	cfi_adjust_cfa_offset (4)
8f5ca04b	64	pushl %ecx
0ecb606c	65	cfi_adjust_cfa_offset (4)
8f5ca04b	66	pushl %ecx
0ecb606c	67	cfi_adjust_cfa_offset (4)
8f5ca04b	68	pushl %ecx
0ecb606c	69	cfi_adjust_cfa_offset (4)
8f5ca04b	70	pushl %ecx
0ecb606c	71	cfi_adjust_cfa_offset (4)
8f5ca04b	72	pushl %ecx
0ecb606c	73	cfi_adjust_cfa_offset (4)
8f5ca04b	74	pushl %ecx
0ecb606c	75	cfi_adjust_cfa_offset (4)
8f5ca04b	76	pushl %ecx
0ecb606c	77	cfi_adjust_cfa_offset (4)
8f5ca04b	78	pushl %ecx
0ecb606c	79	cfi_adjust_cfa_offset (4)
8f5ca04b	80	pushl %ecx
0ecb606c	81	cfi_adjust_cfa_offset (4)
8f5ca04b	82	pushl %ecx
0ecb606c	83	cfi_adjust_cfa_offset (4)
8f5ca04b	84	pushl %ecx
0ecb606c	85	cfi_adjust_cfa_offset (4)
8f5ca04b	86	pushl %ecx
0ecb606c	87	cfi_adjust_cfa_offset (4)
8f5ca04b	88	pushl %ecx
0ecb606c	89	cfi_adjust_cfa_offset (4)
8f5ca04b	90	pushl %ecx
0ecb606c	91	cfi_adjust_cfa_offset (4)
8f5ca04b	92	pushl %ecx
0ecb606c	93	cfi_adjust_cfa_offset (4)
8f5ca04b	94	pushl %ecx
0ecb606c	95	cfi_adjust_cfa_offset (4)
8f5ca04b	96	pushl %ecx
0ecb606c	97	cfi_adjust_cfa_offset (4)
8f5ca04b	98	pushl %ecx
0ecb606c	99	cfi_adjust_cfa_offset (4)
8f5ca04b	100	pushl %ecx
0ecb606c	101	cfi_adjust_cfa_offset (4)
8f5ca04b	102	pushl %ecx
0ecb606c	103	cfi_adjust_cfa_offset (4)
8f5ca04b	104	pushl %ecx
0ecb606c	105	cfi_adjust_cfa_offset (4)
8f5ca04b	106	pushl %ecx
0ecb606c	107	cfi_adjust_cfa_offset (4)
8f5ca04b	108	pushl %ecx
0ecb606c	109	cfi_adjust_cfa_offset (4)
8f5ca04b	110	pushl %ecx
0ecb606c	111	cfi_adjust_cfa_offset (4)
8f5ca04b	112	pushl %ecx
0ecb606c	113	cfi_adjust_cfa_offset (4)
8f5ca04b	114	pushl %ecx
0ecb606c	115	cfi_adjust_cfa_offset (4)
8f5ca04b	116	pushl %ecx
0ecb606c	117	cfi_adjust_cfa_offset (4)
8f5ca04b	118	pushl %ecx
0ecb606c	119	cfi_adjust_cfa_offset (4)
8f5ca04b	120	pushl %ecx
0ecb606c	121	cfi_adjust_cfa_offset (4)
8f5ca04b	122	pushl %ecx
0ecb606c	123	cfi_adjust_cfa_offset (4)
8f5ca04b	124	pushl %ecx
0ecb606c	125	cfi_adjust_cfa_offset (4)
8f5ca04b	126	pushl %ecx
0ecb606c	127	cfi_adjust_cfa_offset (4)
8f5ca04b	128	pushl %ecx
0ecb606c	129	cfi_adjust_cfa_offset (4)
8f5ca04b	130	pushl %ecx
0ecb606c	131	cfi_adjust_cfa_offset (4)
8f5ca04b	132	pushl %ecx
0ecb606c	133	cfi_adjust_cfa_offset (4)
8f5ca04b	134	pushl %ecx
0ecb606c	135	cfi_adjust_cfa_offset (4)
8f5ca04b	136	pushl %ecx
0ecb606c	137	cfi_adjust_cfa_offset (4)
8f5ca04b	138	pushl %ecx
0ecb606c	139	cfi_adjust_cfa_offset (4)
8f5ca04b	140	pushl %ecx
0ecb606c	141	cfi_adjust_cfa_offset (4)
8f5ca04b	142	pushl %ecx
0ecb606c	143	cfi_adjust_cfa_offset (4)
8f5ca04b	144	pushl %ecx
0ecb606c	145	cfi_adjust_cfa_offset (4)
8f5ca04b	146	pushl %ecx
0ecb606c	147	cfi_adjust_cfa_offset (4)
8f5ca04b	148	pushl %ecx
0ecb606c	149	cfi_adjust_cfa_offset (4)
8f5ca04b	150	pushl %ecx
0ecb606c	151	cfi_adjust_cfa_offset (4)
8f5ca04b	152	pushl %ecx
0ecb606c	153	cfi_adjust_cfa_offset (4)
8f5ca04b	154	pushl %ecx
0ecb606c	155	cfi_adjust_cfa_offset (4)
8f5ca04b	156	pushl %ecx
0ecb606c	157	cfi_adjust_cfa_offset (4)
8f5ca04b	158	pushl %ecx
0ecb606c	159	cfi_adjust_cfa_offset (4)
8f5ca04b	160	pushl %ecx
0ecb606c	161	cfi_adjust_cfa_offset (4)
8f5ca04b	162	pushl %ecx
0ecb606c	163	cfi_adjust_cfa_offset (4)
8f5ca04b	164	pushl $0 /* These immediate values make the label 2 */
0ecb606c	165	cfi_adjust_cfa_offset (4)
8f5ca04b	166	pushl $0 /* to be aligned on a 16 byte boundary to */
0ecb606c	167	cfi_adjust_cfa_offset (4)
8f5ca04b	168	pushl $0 /* get a better performance of the loop. */
0ecb606c	169	cfi_adjust_cfa_offset (4)
8f5ca04b	170	pushl $0
0ecb606c	171	cfi_adjust_cfa_offset (4)
8f5ca04b	172	pushl $0
0ecb606c	173	cfi_adjust_cfa_offset (4)
8f5ca04b	174	pushl $0
0ecb606c	175	cfi_adjust_cfa_offset (4)
8f5ca04b RM	176
	177	/* For understanding the following code remember that %ecx == 0 now.
	178	Although all the following instruction only modify %cl we always
	179	have a correct zero-extended 32-bit value in %ecx. */
	180
	181	/* Don't change the "testb $0xff,%%cl" to "testb %%cl,%%cl". We want
	182	longer instructions so that the next loop aligns without adding nops. */
	183
5929563f	184	L(2): movb (%eax), %cl /* get byte from stopset */
8f5ca04b	185	testb %cl, %cl /* is NUL char? */
5929563f	186	jz L(1) /* yes => start compare loop */
8f5ca04b RM	187	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	188
	189	movb 1(%eax), %cl /* get byte from stopset */
	190	testb $0xff, %cl /* is NUL char? */
5929563f	191	jz L(1) /* yes => start compare loop */
8f5ca04b RM	192	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	193
	194	movb 2(%eax), %cl /* get byte from stopset */
	195	testb $0xff, %cl /* is NUL char? */
5929563f	196	jz L(1) /* yes => start compare loop */
8f5ca04b RM	197	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	198
	199	movb 3(%eax), %cl /* get byte from stopset */
	200	addl $4, %eax /* increment stopset pointer */
	201	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	202	testb $0xff, %cl /* is NUL char? */
5929563f	203	jnz L(2) /* no => process next dword from stopset */
8f5ca04b	204
5929563f	205	L(1): leal -4(%edx), %eax /* prepare loop */
8f5ca04b RM	206
	207	/* We use a neat trick for the following loop. Normally we would
	208	have to test for two termination conditions
	209	1. a character in the stopset was found
	210	and
	211	2. the end of the string was found
6d52618b	212	But as a sign that the character is in the stopset we store its
8f5ca04b RM	213	value in the table. But the value of NUL is NUL so the loop
	214	terminates for NUL in every case. */
	215
5929563f	216	L(3): addl $4, %eax /* adjust pointer for full loop round */
8f5ca04b RM	217
	218	movb (%eax), %cl /* get byte from string */
	219	testb %cl, (%esp,%ecx) /* is it contained in skipset? */
5929563f	220	jz L(4) /* no => return */
8f5ca04b RM	221
	222	movb 1(%eax), %cl /* get byte from string */
	223	testb %cl, (%esp,%ecx) /* is it contained in skipset? */
5929563f	224	jz L(5) /* no => return */
8f5ca04b RM	225
	226	movb 2(%eax), %cl /* get byte from string */
	227	testb %cl, (%esp,%ecx) /* is it contained in skipset? */
5929563f	228	jz L(6) /* no => return */
8f5ca04b RM	229
	230	movb 3(%eax), %cl /* get byte from string */
	231	testb %cl, (%esp,%ecx) /* is it contained in skipset? */
5929563f	232	jnz L(3) /* yes => start loop again */
8f5ca04b RM	233
8f5ca04b RM	234	incl %eax /* adjust pointer */
5929563f UD	235	L(6): incl %eax
5929563f UD	236	L(5): incl %eax
8f5ca04b	237
2fc08826	238	L(4): addl $256, %esp /* remove stopset */
0ecb606c	239	cfi_adjust_cfa_offset (-256)
2fc08826 GM	240	CHECK_BOUNDS_HIGH (%eax, STR(%esp), jb)
2fc08826 GM	241	subl %edx, %eax /* we have to return the number of valid
8f5ca04b RM	242	characters, so compute distance to first
8f5ca04b RM	243	non-valid character */
3f02f778	244	LEAVE
8f5ca04b	245	ret
2fc08826	246	END (BP_SYM (strspn))
85dd1003	247	libc_hidden_builtin_def (strspn)