NetBSD/sys/lib/libkern/arch/i386/strcmp.S

/*
 * Written by J.T. Conklin <jtc@netbsd.org>.
 * Public domain.
 */

#include <machine/asm.h>

#if defined(LIBC_SCCS)
	RCSID("$NetBSD: strcmp.S,v 1.8 1999/08/23 09:07:35 kleink Exp $")
#endif

/*
 * NOTE: I've unrolled the loop eight times: large enough to make a
 * significant difference, and small enough not to totally trash the
 * cache.
 */

ENTRY(strcmp)
	movl	0x04(%esp),%eax
	movl	0x08(%esp),%edx
	jmp	L2			/* Jump into the loop! */

	_ALIGN_TEXT,0x90
L1:	incl	%eax
	incl	%edx
L2:	movb	(%eax),%cl
	testb	%cl,%cl			/* null terminator??? */
	jz	L3
	cmpb	%cl,(%edx)		/* chars match??? */
	jne	L3
	incl	%eax
	incl	%edx
	movb	(%eax),%cl
	testb	%cl,%cl
	jz	L3
	cmpb	%cl,(%edx)
	jne	L3
	incl	%eax
	incl	%edx
	movb	(%eax),%cl
	testb	%cl,%cl
	jz	L3
	cmpb	%cl,(%edx)
	jne	L3
	incl	%eax
	incl	%edx
	movb	(%eax),%cl
	testb	%cl,%cl
	jz	L3
	cmpb	%cl,(%edx)
	jne	L3
	incl	%eax
	incl	%edx
	movb	(%eax),%cl
	testb	%cl,%cl
	jz	L3
	cmpb	%cl,(%edx)
	jne	L3
	incl	%eax
	incl	%edx
	movb	(%eax),%cl
	testb	%cl,%cl
	jz	L3
	cmpb	%cl,(%edx)
	jne	L3
	incl	%eax
	incl	%edx
	movb	(%eax),%cl
	testb	%cl,%cl
	jz	L3
	cmpb	%cl,(%edx)
	jne	L3
	incl	%eax
	incl	%edx
	movb	(%eax),%cl
	testb	%cl,%cl
	jz	L3
	cmpb	%cl,(%edx)
	je	L1
	_ALIGN_TEXT,0x90
L3:	movzbl	(%eax),%eax		/* unsigned comparison */
	movzbl	(%edx),%edx
	subl	%edx,%eax
	ret
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`/*`
Update from libc. 1995-10-07 12:26:14 +03:00			`* Written by J.T. Conklin <jtc@netbsd.org>.`
			`* Public domain.`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`*/`

Sync with libc. 1995-02-05 18:06:43 +03:00			`#include <machine/asm.h>`

change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`#if defined(LIBC_SCCS)`
Sync with libc: use _ALIGN_TEXT from <machine/asm.h>. 1999-08-23 13:07:35 +04:00			`RCSID("$NetBSD: strcmp.S,v 1.8 1999/08/23 09:07:35 kleink Exp $")`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`#endif`

			`/*`
Update from libc. 1995-10-07 12:26:14 +03:00			`* NOTE: I've unrolled the loop eight times: large enough to make a`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`* significant difference, and small enough not to totally trash the`
Update from libc. 1994-02-15 16:42:30 +03:00			`* cache.`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`*/`

			`ENTRY(strcmp)`
			`movl 0x04(%esp),%eax`
			`movl 0x08(%esp),%edx`
			`jmp L2 /* Jump into the loop! */`

Sync with libc: use _ALIGN_TEXT from <machine/asm.h>. 1999-08-23 13:07:35 +04:00			`_ALIGN_TEXT,0x90`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`L1: incl %eax`
			`incl %edx`
			`L2: movb (%eax),%cl`
			`testb %cl,%cl /* null terminator??? */`
Update from libc. 1994-02-15 16:42:30 +03:00			`jz L3`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`cmpb %cl,(%edx) /* chars match??? */`
			`jne L3`
			`incl %eax`
			`incl %edx`
			`movb (%eax),%cl`
			`testb %cl,%cl`
Update from libc. 1994-02-15 16:42:30 +03:00			`jz L3`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`cmpb %cl,(%edx)`
			`jne L3`
			`incl %eax`
			`incl %edx`
			`movb (%eax),%cl`
			`testb %cl,%cl`
Update from libc. 1994-02-15 16:42:30 +03:00			`jz L3`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`cmpb %cl,(%edx)`
			`jne L3`
			`incl %eax`
			`incl %edx`
			`movb (%eax),%cl`
			`testb %cl,%cl`
Update from libc. 1994-02-15 16:42:30 +03:00			`jz L3`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`cmpb %cl,(%edx)`
			`jne L3`
			`incl %eax`
			`incl %edx`
			`movb (%eax),%cl`
			`testb %cl,%cl`
Update from libc. 1994-02-15 16:42:30 +03:00			`jz L3`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`cmpb %cl,(%edx)`
			`jne L3`
			`incl %eax`
			`incl %edx`
			`movb (%eax),%cl`
			`testb %cl,%cl`
Update from libc. 1994-02-15 16:42:30 +03:00			`jz L3`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`cmpb %cl,(%edx)`
			`jne L3`
			`incl %eax`
			`incl %edx`
			`movb (%eax),%cl`
			`testb %cl,%cl`
Update from libc. 1994-02-15 16:42:30 +03:00			`jz L3`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`cmpb %cl,(%edx)`
			`jne L3`
			`incl %eax`
			`incl %edx`
			`movb (%eax),%cl`
			`testb %cl,%cl`
Update from libc. 1994-02-15 16:42:30 +03:00			`jz L3`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`cmpb %cl,(%edx)`
			`je L1`
Sync with libc: use _ALIGN_TEXT from <machine/asm.h>. 1999-08-23 13:07:35 +04:00			`_ALIGN_TEXT,0x90`
Update from libc. 1994-02-15 16:42:30 +03:00			`L3: movzbl (%eax),%eax /* unsigned comparison */`
			`movzbl (%edx),%edx`
change to use MACHINE_ARCH and update from libc 1993-12-04 06:05:16 +03:00			`subl %edx,%eax`
			`ret`