opnsense-src/lib/libc/amd64/string/bcmp.S

#include <machine/asm.h>
__FBSDID("$FreeBSD$");

#if 0
	RCSID("$NetBSD: bcmp.S,v 1.1 2001/06/19 00:25:04 fvdl Exp $")
#endif

ENTRY(bcmp)
	cld				/* set compare direction forward */

	movq	%rdx,%rcx		/* compare by words */
	shrq	$3,%rcx
	repe
	cmpsq
	jne	L1

	movq	%rdx,%rcx		/* compare remainder by bytes */
	andq	$7,%rcx
	repe
	cmpsb
L1:
	setne	%al
	movsbl	%al,%eax
	ret
END(bcmp)

	.section .note.GNU-stack,"",%progbits
Add machine-specific, optimized implementations of bcmp and memcmp. PR: 73111 Submitted by: Ville-Pertti Keinonen <will@iki.fi> (taken from NetBSD) MFC after: 3 weeks 2005-04-08 01:15:55 -04:00			`#include <machine/asm.h>`
			`__FBSDID("$FreeBSD$");`

			`#if 0`
			`RCSID("$NetBSD: bcmp.S,v 1.1 2001/06/19 00:25:04 fvdl Exp $")`
			`#endif`

			`ENTRY(bcmp)`
			`cld /* set compare direction forward */`

			`movq %rdx,%rcx /* compare by words */`
			`shrq $3,%rcx`
			`repe`
			`cmpsq`
			`jne L1`

			`movq %rdx,%rcx /* compare remainder by bytes */`
			`andq $7,%rcx`
			`repe`
			`cmpsb`
Eliminate a conditional branch and as a side-effect eliminate a branch to a return instruction. (The latter is discouraged by the Opteron optimization manual because it disables branch prediction for the return instruction.) Reviewed by: bde 2005-04-10 14:12:07 -04:00			`L1:`
			`setne %al`
			`movsbl %al,%eax`
			`ret`
We've been lax about matching END() macros in asm code for some time. This is used to set the ELF size attribute for functions. It isn't normally critical but some things can make use of it (gdb for stack traces). Valgrind needs it so I'm adding it in. The problem is present on all branches and on both i386 and amd64. 2008-11-01 21:10:54 -04:00			`END(bcmp)`
Add section .note.GNU-stack for assembly files used by 386 and amd64. 2011-01-07 11:08:40 -05:00
			`.section .note.GNU-stack,"",%progbits`