1. 根目录:
2. arch
3. mips
4. include
5. asm
6. div64.h

/*
 * Copyright (C) 2000, 2004  Maciej W. Rozycki
 * Copyright (C) 2003, 07 Ralf Baechle (ralf@linux-mips.org)
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#ifndef __ASM_DIV64_H
#define __ASM_DIV64_H

#include <asm-generic/div64.h>

#if BITS_PER_LONG == 64

#include <linux/types.h>

/*
 * No traps on overflows for any of these...
 */

#define __div64_32(n, base)						\
({									\
	unsigned long __cf, __tmp, __tmp2, __i;				\
	unsigned long __quot32, __mod32;				\
	unsigned long __high, __low;					\
	unsigned long long __n;						\
									\
	__high = *__n >> 32;						\
	__low = __n;							\
	__asm__(							\
	"	.set	push					\n"	\
	"	.set	noat					\n"	\
	"	.set	noreorder				\n"	\
	"	move	%2, $0					\n"	\
	"	move	%3, $0					\n"	\
	"	b	1f					\n"	\
	"	 li	%4, 0x21				\n"	\
	"0:							\n"	\
	"	sll	$1, %0, 0x1				\n"	\
	"	srl	%3, %0, 0x1f				\n"	\
	"	or	%0, $1, %5				\n"	\
	"	sll	%1, %1, 0x1				\n"	\
	"	sll	%2, %2, 0x1				\n"	\
	"1:							\n"	\
	"	bnez	%3, 2f					\n"	\
	"	 sltu	%5, %0, %z6				\n"	\
	"	bnez	%5, 3f					\n"	\
	"2:							\n"	\
	"	 addiu	%4, %4, -1				\n"	\
	"	subu	%0, %0, %z6				\n"	\
	"	addiu	%2, %2, 1				\n"	\
	"3:							\n"	\
	"	bnez	%4, 0b\n\t"					\
	"	 srl	%5, %1, 0x1f\n\t"				\
	"	.set	pop"						\
	: "=&r" (__mod32), "=&r" (__tmp),				\
	  "=&r" (__quot32), "=&r" (__cf),				\
	  "=&r" (__i), "=&r" (__tmp2)					\
	: "Jr" (base), "0" (__high), "1" (__low));			\
									\
	(__n) = __quot32;						\
	__mod32;							\
})

#endif /* BITS_PER_LONG == 64 */

#endif /* __ASM_DIV64_H */