NetBSD/lib/libc/arch/m68k/string/swab.S

/*	$NetBSD: swab.S,v 1.6 1997/01/04 03:26:29 jtc Exp $	*/

#include <machine/asm.h>

ENTRY(swab)
	movl	sp@(4),a0		| source
	movl	sp@(8),a1		| destination
	movl	sp@(12),d0		| count
	lsrl	#1,d0			| count is in bytes; we need words
	jeq	swdone

swloop:
	movw	a0@+,d1
	rorw	#8,d1
	movw	d1,a1@+
	subql	#1,d0
	jne	swloop

swdone:
	rts
#include <machine/asm.h> instead of "DEFS.h" 1997-01-04 06:26:18 +03:00			`/* $NetBSD: swab.S,v 1.6 1997/01/04 03:26:29 jtc Exp $ */`
New style RCS ids, and employ the RCSID() macro. 1995-11-17 23:21:10 +03:00
#include <machine/asm.h> instead of "DEFS.h" 1997-01-04 06:26:18 +03:00			`#include <machine/asm.h>`
Assembler version. 1993-12-07 02:16:05 +03:00
			`ENTRY(swab)`
Make the coding style more consistent. 1995-02-08 21:33:12 +03:00			`movl sp@(4),a0 \| source`
			`movl sp@(8),a1 \| destination`
			`movl sp@(12),d0 \| count`
			`lsrl #1,d0 \| count is in bytes; we need words`
Use jCC instead of bCC, as the assembler will then use the (smaller, faster) byte-displacement form of the instruction if the offset will fit. This happens to be all occurances in this case, so I could have used bCCs. However, a quick survey of the rest of NetBSD's m68k code showed that jCC was used in similar cases. I did the same to be consistant. 1997-01-04 06:21:11 +03:00			`jeq swdone`
Assembler version. 1993-12-07 02:16:05 +03:00
			`swloop:`
			`movw a0@+,d1`
			`rorw #8,d1`
			`movw d1,a1@+`
			`subql #1,d0`
Use jCC instead of bCC, as the assembler will then use the (smaller, faster) byte-displacement form of the instruction if the offset will fit. This happens to be all occurances in this case, so I could have used bCCs. However, a quick survey of the rest of NetBSD's m68k code showed that jCC was used in similar cases. I did the same to be consistant. 1997-01-04 06:21:11 +03:00			`jne swloop`
Assembler version. 1993-12-07 02:16:05 +03:00
			`swdone:`
			`rts`