[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) 1994-2023 Free Software Foundation, Inc.
   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, see
   <https://www.gnu.org/licenses/>.  */

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

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

	.text
ENTRY (strpbrk)

	movl STR(%esp), %edx
	movl STOP(%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 */
	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 */
	cfi_adjust_cfa_offset (-256)

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

L(7):	ret
END (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.
6d7e8eda	4	Copyright (C) 1994-2023 Free Software Foundation, Inc.
5929563f UD	5	This file is part of the GNU C Library.
	6
	7	The GNU C Library is free software; you can redistribute it and/or
41bdb6e2 AJ	8	modify it under the terms of the GNU Lesser General Public
	9	License as published by the Free Software Foundation; either
	10	version 2.1 of the License, or (at your option) any later version.
5929563f UD	11
	12	The GNU C Library is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
41bdb6e2	15	Lesser General Public License for more details.
5929563f	16
41bdb6e2	17	You should have received a copy of the GNU Lesser General Public
59ba27a6	18	License along with the GNU C Library; if not, see
5a82c748	19	<https://www.gnu.org/licenses/>. */
8f5ca04b RM	20
	21	#include <sysdep.h>
	22	#include "asm-syntax.h"
	23
2366713d	24	#define PARMS 4 /* no space for saved regs */
3f02f778	25	#define RTN PARMS
2366713d JM	26	#define STR RTN
2366713d JM	27	#define STOP STR+4
8f5ca04b RM	28
8f5ca04b RM	29	.text
2366713d	30	ENTRY (strpbrk)
3f02f778 GM	31
	32	movl STR(%esp), %edx
	33	movl STOP(%esp), %eax
8f5ca04b RM	34
	35	/* First we create a table with flags for all possible characters.
	36	For the ASCII (7bit/8bit) or ISO-8859-X character sets which are
	37	supported by the C string functions we have 256 characters.
	38	Before inserting marks for the stop characters we clear the whole
	39	table. The unrolled form is much faster than a loop. */
	40	xorl %ecx, %ecx /* %ecx = 0 !!! */
	41
	42	pushl %ecx /* make a 256 bytes long block filled with 0 */
1ad9da69	43	cfi_adjust_cfa_offset (4)
8f5ca04b	44	pushl %ecx
1ad9da69	45	cfi_adjust_cfa_offset (4)
8f5ca04b	46	pushl %ecx
1ad9da69	47	cfi_adjust_cfa_offset (4)
8f5ca04b	48	pushl %ecx
1ad9da69	49	cfi_adjust_cfa_offset (4)
8f5ca04b	50	pushl %ecx
1ad9da69	51	cfi_adjust_cfa_offset (4)
8f5ca04b	52	pushl %ecx
1ad9da69	53	cfi_adjust_cfa_offset (4)
8f5ca04b	54	pushl %ecx
1ad9da69	55	cfi_adjust_cfa_offset (4)
8f5ca04b	56	pushl %ecx
1ad9da69	57	cfi_adjust_cfa_offset (4)
8f5ca04b	58	pushl %ecx
1ad9da69	59	cfi_adjust_cfa_offset (4)
8f5ca04b	60	pushl %ecx
1ad9da69	61	cfi_adjust_cfa_offset (4)
8f5ca04b	62	pushl %ecx
1ad9da69	63	cfi_adjust_cfa_offset (4)
8f5ca04b	64	pushl %ecx
1ad9da69	65	cfi_adjust_cfa_offset (4)
8f5ca04b	66	pushl %ecx
1ad9da69	67	cfi_adjust_cfa_offset (4)
8f5ca04b	68	pushl %ecx
1ad9da69	69	cfi_adjust_cfa_offset (4)
8f5ca04b	70	pushl %ecx
1ad9da69	71	cfi_adjust_cfa_offset (4)
8f5ca04b	72	pushl %ecx
1ad9da69	73	cfi_adjust_cfa_offset (4)
8f5ca04b	74	pushl %ecx
1ad9da69	75	cfi_adjust_cfa_offset (4)
8f5ca04b	76	pushl %ecx
1ad9da69	77	cfi_adjust_cfa_offset (4)
8f5ca04b	78	pushl %ecx
1ad9da69	79	cfi_adjust_cfa_offset (4)
8f5ca04b	80	pushl %ecx
1ad9da69	81	cfi_adjust_cfa_offset (4)
8f5ca04b	82	pushl %ecx
1ad9da69	83	cfi_adjust_cfa_offset (4)
8f5ca04b	84	pushl %ecx
1ad9da69	85	cfi_adjust_cfa_offset (4)
8f5ca04b	86	pushl %ecx
1ad9da69	87	cfi_adjust_cfa_offset (4)
8f5ca04b	88	pushl %ecx
1ad9da69	89	cfi_adjust_cfa_offset (4)
8f5ca04b	90	pushl %ecx
1ad9da69	91	cfi_adjust_cfa_offset (4)
8f5ca04b	92	pushl %ecx
1ad9da69	93	cfi_adjust_cfa_offset (4)
8f5ca04b	94	pushl %ecx
1ad9da69	95	cfi_adjust_cfa_offset (4)
8f5ca04b	96	pushl %ecx
1ad9da69	97	cfi_adjust_cfa_offset (4)
8f5ca04b	98	pushl %ecx
1ad9da69	99	cfi_adjust_cfa_offset (4)
8f5ca04b	100	pushl %ecx
1ad9da69	101	cfi_adjust_cfa_offset (4)
8f5ca04b	102	pushl %ecx
1ad9da69	103	cfi_adjust_cfa_offset (4)
8f5ca04b	104	pushl %ecx
1ad9da69	105	cfi_adjust_cfa_offset (4)
8f5ca04b	106	pushl %ecx
1ad9da69	107	cfi_adjust_cfa_offset (4)
8f5ca04b	108	pushl %ecx
1ad9da69	109	cfi_adjust_cfa_offset (4)
8f5ca04b	110	pushl %ecx
1ad9da69	111	cfi_adjust_cfa_offset (4)
8f5ca04b	112	pushl %ecx
1ad9da69	113	cfi_adjust_cfa_offset (4)
8f5ca04b	114	pushl %ecx
1ad9da69	115	cfi_adjust_cfa_offset (4)
8f5ca04b	116	pushl %ecx
1ad9da69	117	cfi_adjust_cfa_offset (4)
8f5ca04b	118	pushl %ecx
1ad9da69	119	cfi_adjust_cfa_offset (4)
8f5ca04b	120	pushl %ecx
1ad9da69	121	cfi_adjust_cfa_offset (4)
8f5ca04b	122	pushl %ecx
1ad9da69	123	cfi_adjust_cfa_offset (4)
8f5ca04b	124	pushl %ecx
1ad9da69	125	cfi_adjust_cfa_offset (4)
8f5ca04b	126	pushl %ecx
1ad9da69	127	cfi_adjust_cfa_offset (4)
8f5ca04b	128	pushl %ecx
1ad9da69	129	cfi_adjust_cfa_offset (4)
8f5ca04b	130	pushl %ecx
1ad9da69	131	cfi_adjust_cfa_offset (4)
8f5ca04b	132	pushl %ecx
1ad9da69	133	cfi_adjust_cfa_offset (4)
8f5ca04b	134	pushl %ecx
1ad9da69	135	cfi_adjust_cfa_offset (4)
8f5ca04b	136	pushl %ecx
1ad9da69	137	cfi_adjust_cfa_offset (4)
8f5ca04b	138	pushl %ecx
1ad9da69	139	cfi_adjust_cfa_offset (4)
8f5ca04b	140	pushl %ecx
1ad9da69	141	cfi_adjust_cfa_offset (4)
8f5ca04b	142	pushl %ecx
1ad9da69	143	cfi_adjust_cfa_offset (4)
8f5ca04b	144	pushl %ecx
1ad9da69	145	cfi_adjust_cfa_offset (4)
8f5ca04b	146	pushl %ecx
1ad9da69	147	cfi_adjust_cfa_offset (4)
8f5ca04b	148	pushl %ecx
1ad9da69	149	cfi_adjust_cfa_offset (4)
8f5ca04b	150	pushl %ecx
1ad9da69	151	cfi_adjust_cfa_offset (4)
8f5ca04b	152	pushl %ecx
1ad9da69	153	cfi_adjust_cfa_offset (4)
8f5ca04b	154	pushl %ecx
1ad9da69	155	cfi_adjust_cfa_offset (4)
8f5ca04b	156	pushl %ecx
1ad9da69	157	cfi_adjust_cfa_offset (4)
8f5ca04b	158	pushl $0 /* These immediate values make the label 2 */
1ad9da69	159	cfi_adjust_cfa_offset (4)
8f5ca04b	160	pushl $0 /* to be aligned on a 16 byte boundary to */
1ad9da69	161	cfi_adjust_cfa_offset (4)
8f5ca04b	162	pushl $0 /* get a better performance of the loop. */
1ad9da69	163	cfi_adjust_cfa_offset (4)
8f5ca04b	164	pushl $0
1ad9da69	165	cfi_adjust_cfa_offset (4)
8f5ca04b	166	pushl $0
1ad9da69	167	cfi_adjust_cfa_offset (4)
8f5ca04b	168	pushl $0
1ad9da69	169	cfi_adjust_cfa_offset (4)
8f5ca04b RM	170
	171	/* For understanding the following code remember that %ecx == 0 now.
	172	Although all the following instruction only modify %cl we always
	173	have a correct zero-extended 32-bit value in %ecx. */
	174
	175	/* Don't change the "testb $0xff,%%cl" to "testb %%cl,%%cl". We want
	176	longer instructions so that the next loop aligns without adding nops. */
	177
5929563f	178	L(2): movb (%eax), %cl /* get byte from stopset */
8f5ca04b	179	testb %cl, %cl /* is NUL char? */
5929563f	180	jz L(1) /* yes => start compare loop */
8f5ca04b RM	181	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	182
	183	movb 1(%eax), %cl /* get byte from stopset */
	184	testb $0xff, %cl /* is NUL char? */
5929563f	185	jz L(1) /* yes => start compare loop */
8f5ca04b RM	186	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	187
	188	movb 2(%eax), %cl /* get byte from stopset */
	189	testb $0xff, %cl /* is NUL char? */
5929563f	190	jz L(1) /* yes => start compare loop */
8f5ca04b RM	191	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	192
	193	movb 3(%eax), %cl /* get byte from stopset */
	194	addl $4, %eax /* increment stopset pointer */
	195	movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */
	196	testb $0xff, %cl /* is NUL char? */
5929563f	197	jnz L(2) /* no => process next dword from stopset */
8f5ca04b	198
5929563f	199	L(1): leal -4(%edx), %eax /* prepare loop */
8f5ca04b RM	200
	201	/* We use a neat trick for the following loop. Normally we would
	202	have to test for two termination conditions
	203	1. a character in the stopset was found
	204	and
	205	2. the end of the string was found
382466e0	206	But as a sign that the character is in the stopset we store its
8f5ca04b RM	207	value in the table. But the value of NUL is NUL so the loop
	208	terminates for NUL in every case. */
	209
5929563f	210	L(3): addl $4, %eax /* adjust pointer for full loop round */
8f5ca04b RM	211
	212	movb (%eax), %cl /* get byte from string */
	213	cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
5929563f	214	je L(4) /* yes => return */
8f5ca04b RM	215
	216	movb 1(%eax), %cl /* get byte from string */
	217	cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
5929563f	218	je L(5) /* yes => return */
8f5ca04b RM	219
	220	movb 2(%eax), %cl /* get byte from string */
	221	cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
5929563f	222	je L(6) /* yes => return */
8f5ca04b RM	223
	224	movb 3(%eax), %cl /* get byte from string */
	225	cmpb %cl, (%esp,%ecx) /* is it contained in stopset? */
5929563f	226	jne L(3) /* yes => return */
8f5ca04b RM	227
8f5ca04b RM	228	incl %eax /* adjust pointer */
5929563f UD	229	L(6): incl %eax
5929563f UD	230	L(5): incl %eax
8f5ca04b	231
5929563f	232	L(4): addl $256, %esp /* remove stopset */
1ad9da69	233	cfi_adjust_cfa_offset (-256)
8f5ca04b RM	234
8f5ca04b RM	235	orb %cl, %cl /* was last character NUL? */
2fc08826 GM	236	jnz L(7) /* no => return pointer */
2fc08826 GM	237	xorl %eax, %eax
8f5ca04b	238
2366713d JM	239	L(7): ret
2366713d JM	240	END (strpbrk)
85dd1003	241	libc_hidden_builtin_def (strpbrk)