[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) 1994-2019 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, see
   <https://www.gnu.org/licenses/>.  */

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

#define PARMS	4		/* no space for saved regs */
#define STR	PARMS
#define SKIP	STR+4

	.text
ENTRY (strspn)

	movl STR(%esp), %edx
	movl SKIP(%esp), %eax

	/* 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)
	subl %edx, %eax		/* we have to return the number of valid
				   characters, so compute distance to first
				   non-valid character */
	ret
END (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.
04277e02	4	Copyright (C) 1994-2019 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	19	You should have received a copy of the GNU Lesser General Public
59ba27a6	20	License along with the GNU C Library; if not, see
5a82c748	21	<https://www.gnu.org/licenses/>. */
8f5ca04b RM	22
	23	#include <sysdep.h>
	24	#include "asm-syntax.h"
	25
2366713d	26	#define PARMS 4 /* no space for saved regs */
3f02f778	27	#define STR PARMS
2366713d	28	#define SKIP STR+4
8f5ca04b RM	29
8f5ca04b RM	30	.text
2366713d	31	ENTRY (strspn)
3f02f778 GM	32
	33	movl STR(%esp), %edx
	34	movl SKIP(%esp), %eax
8f5ca04b RM	35
	36	/* First we create a table with flags for all possible characters.
	37	For the ASCII (7bit/8bit) or ISO-8859-X character sets which are
	38	supported by the C string functions we have 256 characters.
	39	Before inserting marks for the stop characters we clear the whole
	40	table. The unrolled form is much faster than a loop. */
	41	xorl %ecx, %ecx /* %ecx = 0 !!! */
	42
	43	pushl %ecx /* make a 256 bytes long block filled with 0 */
1ad9da69	44	cfi_adjust_cfa_offset (4)
8f5ca04b	45	pushl %ecx
1ad9da69	46	cfi_adjust_cfa_offset (4)
8f5ca04b	47	pushl %ecx
1ad9da69	48	cfi_adjust_cfa_offset (4)
8f5ca04b	49	pushl %ecx
1ad9da69	50	cfi_adjust_cfa_offset (4)
8f5ca04b	51	pushl %ecx
1ad9da69	52	cfi_adjust_cfa_offset (4)
8f5ca04b	53	pushl %ecx
1ad9da69	54	cfi_adjust_cfa_offset (4)
8f5ca04b	55	pushl %ecx
1ad9da69	56	cfi_adjust_cfa_offset (4)
8f5ca04b	57	pushl %ecx
1ad9da69	58	cfi_adjust_cfa_offset (4)
8f5ca04b	59	pushl %ecx
1ad9da69	60	cfi_adjust_cfa_offset (4)
8f5ca04b	61	pushl %ecx
1ad9da69	62	cfi_adjust_cfa_offset (4)
8f5ca04b	63	pushl %ecx
1ad9da69	64	cfi_adjust_cfa_offset (4)
8f5ca04b	65	pushl %ecx
1ad9da69	66	cfi_adjust_cfa_offset (4)
8f5ca04b	67	pushl %ecx
1ad9da69	68	cfi_adjust_cfa_offset (4)
8f5ca04b	69	pushl %ecx
1ad9da69	70	cfi_adjust_cfa_offset (4)
8f5ca04b	71	pushl %ecx
1ad9da69	72	cfi_adjust_cfa_offset (4)
8f5ca04b	73	pushl %ecx
1ad9da69	74	cfi_adjust_cfa_offset (4)
8f5ca04b	75	pushl %ecx
1ad9da69	76	cfi_adjust_cfa_offset (4)
8f5ca04b	77	pushl %ecx
1ad9da69	78	cfi_adjust_cfa_offset (4)
8f5ca04b	79	pushl %ecx
1ad9da69	80	cfi_adjust_cfa_offset (4)
8f5ca04b	81	pushl %ecx
1ad9da69	82	cfi_adjust_cfa_offset (4)
8f5ca04b	83	pushl %ecx
1ad9da69	84	cfi_adjust_cfa_offset (4)
8f5ca04b	85	pushl %ecx
1ad9da69	86	cfi_adjust_cfa_offset (4)
8f5ca04b	87	pushl %ecx
1ad9da69	88	cfi_adjust_cfa_offset (4)
8f5ca04b	89	pushl %ecx
1ad9da69	90	cfi_adjust_cfa_offset (4)
8f5ca04b	91	pushl %ecx
1ad9da69	92	cfi_adjust_cfa_offset (4)
8f5ca04b	93	pushl %ecx
1ad9da69	94	cfi_adjust_cfa_offset (4)
8f5ca04b	95	pushl %ecx
1ad9da69	96	cfi_adjust_cfa_offset (4)
8f5ca04b	97	pushl %ecx
1ad9da69	98	cfi_adjust_cfa_offset (4)
8f5ca04b	99	pushl %ecx
1ad9da69	100	cfi_adjust_cfa_offset (4)
8f5ca04b	101	pushl %ecx
1ad9da69	102	cfi_adjust_cfa_offset (4)
8f5ca04b	103	pushl %ecx
1ad9da69	104	cfi_adjust_cfa_offset (4)
8f5ca04b	105	pushl %ecx
1ad9da69	106	cfi_adjust_cfa_offset (4)
8f5ca04b	107	pushl %ecx
1ad9da69	108	cfi_adjust_cfa_offset (4)
8f5ca04b	109	pushl %ecx
1ad9da69	110	cfi_adjust_cfa_offset (4)
8f5ca04b	111	pushl %ecx
1ad9da69	112	cfi_adjust_cfa_offset (4)
8f5ca04b	113	pushl %ecx
1ad9da69	114	cfi_adjust_cfa_offset (4)
8f5ca04b	115	pushl %ecx
1ad9da69	116	cfi_adjust_cfa_offset (4)
8f5ca04b	117	pushl %ecx
1ad9da69	118	cfi_adjust_cfa_offset (4)
8f5ca04b	119	pushl %ecx
1ad9da69	120	cfi_adjust_cfa_offset (4)
8f5ca04b	121	pushl %ecx
1ad9da69	122	cfi_adjust_cfa_offset (4)
8f5ca04b	123	pushl %ecx
1ad9da69	124	cfi_adjust_cfa_offset (4)
8f5ca04b	125	pushl %ecx
1ad9da69	126	cfi_adjust_cfa_offset (4)
8f5ca04b	127	pushl %ecx
1ad9da69	128	cfi_adjust_cfa_offset (4)
8f5ca04b	129	pushl %ecx
1ad9da69	130	cfi_adjust_cfa_offset (4)
8f5ca04b	131	pushl %ecx
1ad9da69	132	cfi_adjust_cfa_offset (4)
8f5ca04b	133	pushl %ecx
1ad9da69	134	cfi_adjust_cfa_offset (4)
8f5ca04b	135	pushl %ecx
1ad9da69	136	cfi_adjust_cfa_offset (4)
8f5ca04b	137	pushl %ecx
1ad9da69	138	cfi_adjust_cfa_offset (4)
8f5ca04b	139	pushl %ecx
1ad9da69	140	cfi_adjust_cfa_offset (4)
8f5ca04b	141	pushl %ecx
1ad9da69	142	cfi_adjust_cfa_offset (4)
8f5ca04b	143	pushl %ecx
1ad9da69	144	cfi_adjust_cfa_offset (4)
8f5ca04b	145	pushl %ecx
1ad9da69	146	cfi_adjust_cfa_offset (4)
8f5ca04b	147	pushl %ecx
1ad9da69	148	cfi_adjust_cfa_offset (4)
8f5ca04b	149	pushl %ecx
1ad9da69	150	cfi_adjust_cfa_offset (4)
8f5ca04b	151	pushl %ecx
1ad9da69	152	cfi_adjust_cfa_offset (4)
8f5ca04b	153	pushl %ecx
1ad9da69	154	cfi_adjust_cfa_offset (4)
8f5ca04b	155	pushl %ecx
1ad9da69	156	cfi_adjust_cfa_offset (4)
8f5ca04b	157	pushl %ecx
1ad9da69	158	cfi_adjust_cfa_offset (4)
8f5ca04b	159	pushl $0 /* These immediate values make the label 2 */
1ad9da69	160	cfi_adjust_cfa_offset (4)
8f5ca04b	161	pushl $0 /* to be aligned on a 16 byte boundary to */
1ad9da69	162	cfi_adjust_cfa_offset (4)
8f5ca04b	163	pushl $0 /* get a better performance of the loop. */
1ad9da69	164	cfi_adjust_cfa_offset (4)
8f5ca04b	165	pushl $0
1ad9da69	166	cfi_adjust_cfa_offset (4)
8f5ca04b	167	pushl $0
1ad9da69	168	cfi_adjust_cfa_offset (4)
8f5ca04b	169	pushl $0
1ad9da69	170	cfi_adjust_cfa_offset (4)
8f5ca04b RM	171
	172	/* For understanding the following code remember that %ecx == 0 now.
	173	Although all the following instruction only modify %cl we always
	174	have a correct zero-extended 32-bit value in %ecx. */
	175
	176	/* Don't change the "testb $0xff,%%cl" to "testb %%cl,%%cl". We want
	177	longer instructions so that the next loop aligns without adding nops. */
	178
5929563f	179	L(2): movb (%eax), %cl /* get byte from stopset */
8f5ca04b	180	testb %cl, %cl /* is NUL char? */
5929563f	181	jz L(1) /* yes => start compare loop */
8f5ca04b RM	182	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	183
	184	movb 1(%eax), %cl /* get byte from stopset */
	185	testb $0xff, %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 2(%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 3(%eax), %cl /* get byte from stopset */
	195	addl $4, %eax /* increment stopset pointer */
	196	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	197	testb $0xff, %cl /* is NUL char? */
5929563f	198	jnz L(2) /* no => process next dword from stopset */
8f5ca04b	199
5929563f	200	L(1): leal -4(%edx), %eax /* prepare loop */
8f5ca04b RM	201
	202	/* We use a neat trick for the following loop. Normally we would
	203	have to test for two termination conditions
	204	1. a character in the stopset was found
	205	and
	206	2. the end of the string was found
6d52618b	207	But as a sign that the character is in the stopset we store its
8f5ca04b RM	208	value in the table. But the value of NUL is NUL so the loop
	209	terminates for NUL in every case. */
	210
5929563f	211	L(3): addl $4, %eax /* adjust pointer for full loop round */
8f5ca04b RM	212
	213	movb (%eax), %cl /* get byte from string */
	214	testb %cl, (%esp,%ecx) /* is it contained in skipset? */
5929563f	215	jz L(4) /* no => return */
8f5ca04b RM	216
	217	movb 1(%eax), %cl /* get byte from string */
	218	testb %cl, (%esp,%ecx) /* is it contained in skipset? */
5929563f	219	jz L(5) /* no => return */
8f5ca04b RM	220
	221	movb 2(%eax), %cl /* get byte from string */
	222	testb %cl, (%esp,%ecx) /* is it contained in skipset? */
5929563f	223	jz L(6) /* no => return */
8f5ca04b RM	224
	225	movb 3(%eax), %cl /* get byte from string */
	226	testb %cl, (%esp,%ecx) /* is it contained in skipset? */
5929563f	227	jnz L(3) /* yes => start loop again */
8f5ca04b RM	228
8f5ca04b RM	229	incl %eax /* adjust pointer */
5929563f UD	230	L(6): incl %eax
5929563f UD	231	L(5): incl %eax
8f5ca04b	232
2fc08826	233	L(4): addl $256, %esp /* remove stopset */
1ad9da69	234	cfi_adjust_cfa_offset (-256)
2fc08826	235	subl %edx, %eax /* we have to return the number of valid
8f5ca04b RM	236	characters, so compute distance to first
8f5ca04b RM	237	non-valid character */
8f5ca04b	238	ret
2366713d	239	END (strspn)
85dd1003	240	libc_hidden_builtin_def (strspn)