WebSVN – Kolibri OS – Diff – /drivers/ddk/linux/div64.c


/*
 * Copyright (C) 2003 Bernardo Innocenti 
 *
 * Based on former do_div() implementation from asm-parisc/div64.h:
 *	Copyright (C) 1999 Hewlett-Packard Co
 *	Copyright (C) 1999 David Mosberger-Tang 
 *
 *
 * Generic C version of 64bit/32bit division and modulo, with
 * 64bit result and 32bit remainder.
 *
 * The fast case for (n>>32 == 0) is handled inline by do_div(). 
 *
 * Code generated for this function might be very inefficient
 * for some CPUs. __div64_32() can be overridden by linking arch-specific
 * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S
 * or by defining a preprocessor macro in arch/include/asm/div64.h.
 */
 
#include 
#include 
#include 
 
/* Not needed on 64bit architectures */
#if BITS_PER_LONG == 32
 
#ifndef __div64_32
uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
{
	uint64_t rem = *n;
	uint64_t b = base;
	uint64_t res, d = 1;
	uint32_t high = rem >> 32;
 
	/* Reduce the thing a bit first */
	res = 0;
	if (high >= base) {
		high /= base;
		res = (uint64_t) high << 32;
		rem -= (uint64_t) (high*base) << 32;
	}
 
	while ((int64_t)b > 0 && b < rem) {
		b = b+b;
		d = d+d;
	}
 
	do {
		if (rem >= b) {
			rem -= b;
			res += d;
		}
		b >>= 1;
		d >>= 1;
	} while (d);
 
	*n = res;
	return rem;
}
 
EXPORT_SYMBOL(__div64_32);
#endif
 
#ifndef div_s64_rem
s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
{
        u64 quotient;
 
        if (dividend < 0) {
                quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder);
                *remainder = -*remainder;
                if (divisor > 0)
                        quotient = -quotient;
        } else {
                quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder);
                if (divisor < 0)
                        quotient = -quotient;
        }
        return quotient;
}
EXPORT_SYMBOL(div_s64_rem);
#endif
 
/**
 * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
 * @dividend:	64bit dividend
 * @divisor:	64bit divisor
 * @remainder:  64bit remainder
 *
 * This implementation is a comparable to algorithm used by div64_u64.
 * But this operation, which includes math for calculating the remainder,
 * is kept distinct to avoid slowing down the div64_u64 operation on 32bit
 * systems.
 */
#ifndef div64_u64_rem
u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
{
	u32 high = divisor >> 32;
	u64 quot;
 
	if (high == 0) {
		u32 rem32;
		quot = div_u64_rem(dividend, divisor, &rem32);
		*remainder = rem32;
	} else {
		int n = 1 + fls(high);
		quot = div_u64(dividend >> n, divisor >> n);
 
		if (quot != 0)
			quot--;
 
		*remainder = dividend - quot * divisor;
		if (*remainder >= divisor) {
			quot++;
			*remainder -= divisor;
		}
	}
 
	return quot;
}
EXPORT_SYMBOL(div64_u64_rem);
#endif
 
/**
 * div64_u64 - unsigned 64bit divide with 64bit divisor
 * @dividend:	64bit dividend
 * @divisor:	64bit divisor
 *
 * This implementation is a modified version of the algorithm proposed
 * by the book 'Hacker's Delight'.  The original source and full proof
 * can be found here and is available for use without restriction.
 *
 * 'http://www.hackersdelight.org/hdcodetxt/divDouble.c.txt'
 */
#ifndef div64_u64
u64 div64_u64(u64 dividend, u64 divisor)
{
	u32 high = divisor >> 32;
	u64 quot;
 
	if (high == 0) {
		quot = div_u64(dividend, divisor);
	} else {
		int n = 1 + fls(high);
		quot = div_u64(dividend >> n, divisor >> n);
 
		if (quot != 0)
			quot--;
		if ((dividend - quot * divisor) >= divisor)
			quot++;
	}
 
	return quot;
}
EXPORT_SYMBOL(div64_u64);
#endif
 
/**
 * div64_s64 - signed 64bit divide with 64bit divisor
 * @dividend:	64bit dividend
 * @divisor:	64bit divisor
 */
#ifndef div64_s64
s64 div64_s64(s64 dividend, s64 divisor)
{
	s64 quot, t;
 
	quot = div64_u64(abs(dividend), abs(divisor));
	t = (dividend ^ divisor) >> 63;
 
	return (quot ^ t) - t;
}
EXPORT_SYMBOL(div64_s64);
#endif
 
#endif /* BITS_PER_LONG == 32 */
 
/*
 * Iterative div/mod for use when dividend is not expected to be much
 * bigger than divisor.
 */
u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
{
	return __iter_div_u64_rem(dividend, divisor, remainder);
}
EXPORT_SYMBOL(iter_div_u64_rem);

Rev 6934	Rev 6936
1	/*	1	/*
2	* Copyright (C) 2003 Bernardo Innocenti	2	* Copyright (C) 2003 Bernardo Innocenti
3	*	3	*
4	* Based on former do_div() implementation from asm-parisc/div64.h:	4	* Based on former do_div() implementation from asm-parisc/div64.h:
5	* Copyright (C) 1999 Hewlett-Packard Co	5	* Copyright (C) 1999 Hewlett-Packard Co
6	* Copyright (C) 1999 David Mosberger-Tang	6	* Copyright (C) 1999 David Mosberger-Tang
7	*	7	*
8	*	8	*
9	* Generic C version of 64bit/32bit division and modulo, with	9	* Generic C version of 64bit/32bit division and modulo, with
10	* 64bit result and 32bit remainder.	10	* 64bit result and 32bit remainder.
11	*	11	*
12	* The fast case for (n>>32 == 0) is handled inline by do_div().	12	* The fast case for (n>>32 == 0) is handled inline by do_div().
13	*	13	*
14	* Code generated for this function might be very inefficient	14	* Code generated for this function might be very inefficient
15	* for some CPUs. __div64_32() can be overridden by linking arch-specific	15	* for some CPUs. __div64_32() can be overridden by linking arch-specific
16	* assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S.	16	* assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S
-		17	* or by defining a preprocessor macro in arch/include/asm/div64.h.
17	*/	18	*/
18		19
19	#include	20	#include
20	#include	21	#include
21	#include	22	#include
22		23
23	/* Not needed on 64bit architectures */	24	/* Not needed on 64bit architectures */
24	#if BITS_PER_LONG == 32	25	#if BITS_PER_LONG == 32
-		26
25		27	#ifndef __div64_32
26	uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)	28	uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
27	{	29	{
28	uint64_t rem = *n;	30	uint64_t rem = *n;
29	uint64_t b = base;	31	uint64_t b = base;
30	uint64_t res, d = 1;	32	uint64_t res, d = 1;
31	uint32_t high = rem >> 32;	33	uint32_t high = rem >> 32;
32		34
33	/* Reduce the thing a bit first */	35	/* Reduce the thing a bit first */
34	res = 0;	36	res = 0;
35	if (high >= base) {	37	if (high >= base) {
36	high /= base;	38	high /= base;
37	res = (uint64_t) high << 32;	39	res = (uint64_t) high << 32;
38	rem -= (uint64_t) (high*base) << 32;	40	rem -= (uint64_t) (high*base) << 32;
39	}	41	}
40		42
41	while ((int64_t)b > 0 && b < rem) {	43	while ((int64_t)b > 0 && b < rem) {
42	b = b+b;	44	b = b+b;
43	d = d+d;	45	d = d+d;
44	}	46	}
45		47
46	do {	48	do {
47	if (rem >= b) {	49	if (rem >= b) {
48	rem -= b;	50	rem -= b;
49	res += d;	51	res += d;
50	}	52	}
51	b >>= 1;	53	b >>= 1;
52	d >>= 1;	54	d >>= 1;
53	} while (d);	55	} while (d);
54		56
55	*n = res;	57	*n = res;
56	return rem;	58	return rem;
57	}	59	}
58		-
59	EXPORT_SYMBOL(__div64_32);	60	EXPORT_SYMBOL(__div64_32);
-		61	#endif
60		62
61	#ifndef div_s64_rem	63	#ifndef div_s64_rem
62	s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)	64	s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
63	{	65	{
64	u64 quotient;	66	u64 quotient;
65		67
66	if (dividend < 0) {	68	if (dividend < 0) {
67	quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder);	69	quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder);
68	remainder = -remainder;	70	remainder = -remainder;
69	if (divisor > 0)	71	if (divisor > 0)
70	quotient = -quotient;	72	quotient = -quotient;
71	} else {	73	} else {
72	quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder);	74	quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder);
73	if (divisor < 0)	75	if (divisor < 0)
74	quotient = -quotient;	76	quotient = -quotient;
75	}	77	}
76	return quotient;	78	return quotient;
77	}	79	}
78	EXPORT_SYMBOL(div_s64_rem);	80	EXPORT_SYMBOL(div_s64_rem);
79	#endif	81	#endif
80		82
81	/**	83	/**
82	* div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder	84	* div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
83	* @dividend: 64bit dividend	85	* @dividend: 64bit dividend
84	* @divisor: 64bit divisor	86	* @divisor: 64bit divisor
85	* @remainder: 64bit remainder	87	* @remainder: 64bit remainder
86	*	88	*
87	* This implementation is a comparable to algorithm used by div64_u64.	89	* This implementation is a comparable to algorithm used by div64_u64.
88	* But this operation, which includes math for calculating the remainder,	90	* But this operation, which includes math for calculating the remainder,
89	* is kept distinct to avoid slowing down the div64_u64 operation on 32bit	91	* is kept distinct to avoid slowing down the div64_u64 operation on 32bit
90	* systems.	92	* systems.
91	*/	93	*/
92	#ifndef div64_u64_rem	94	#ifndef div64_u64_rem
93	u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)	95	u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
94	{	96	{
95	u32 high = divisor >> 32;	97	u32 high = divisor >> 32;
96	u64 quot;	98	u64 quot;
97		99
98	if (high == 0) {	100	if (high == 0) {
99	u32 rem32;	101	u32 rem32;
100	quot = div_u64_rem(dividend, divisor, &rem32);	102	quot = div_u64_rem(dividend, divisor, &rem32);
101	*remainder = rem32;	103	*remainder = rem32;
102	} else {	104	} else {
103	int n = 1 + fls(high);	105	int n = 1 + fls(high);
104	quot = div_u64(dividend >> n, divisor >> n);	106	quot = div_u64(dividend >> n, divisor >> n);
105		107
106	if (quot != 0)	108	if (quot != 0)
107	quot--;	109	quot--;
108		110
109	remainder = dividend - quot divisor;	111	remainder = dividend - quot divisor;
110	if (*remainder >= divisor) {	112	if (*remainder >= divisor) {
111	quot++;	113	quot++;
112	*remainder -= divisor;	114	*remainder -= divisor;
113	}	115	}
114	}	116	}
115		117
116	return quot;	118	return quot;
117	}	119	}
118	EXPORT_SYMBOL(div64_u64_rem);	120	EXPORT_SYMBOL(div64_u64_rem);
119	#endif	121	#endif
120		122
121	/**	123	/**
122	* div64_u64 - unsigned 64bit divide with 64bit divisor	124	* div64_u64 - unsigned 64bit divide with 64bit divisor
123	* @dividend: 64bit dividend	125	* @dividend: 64bit dividend
124	* @divisor: 64bit divisor	126	* @divisor: 64bit divisor
125	*	127	*
126	* This implementation is a modified version of the algorithm proposed	128	* This implementation is a modified version of the algorithm proposed
127	* by the book 'Hacker's Delight'. The original source and full proof	129	* by the book 'Hacker's Delight'. The original source and full proof
128	* can be found here and is available for use without restriction.	130	* can be found here and is available for use without restriction.
129	*	131	*
130	* 'http://www.hackersdelight.org/hdcodetxt/divDouble.c.txt'	132	* 'http://www.hackersdelight.org/hdcodetxt/divDouble.c.txt'
131	*/	133	*/
132	#ifndef div64_u64	134	#ifndef div64_u64
133	u64 div64_u64(u64 dividend, u64 divisor)	135	u64 div64_u64(u64 dividend, u64 divisor)
134	{	136	{
135	u32 high = divisor >> 32;	137	u32 high = divisor >> 32;
136	u64 quot;	138	u64 quot;
137		139
138	if (high == 0) {	140	if (high == 0) {
139	quot = div_u64(dividend, divisor);	141	quot = div_u64(dividend, divisor);
140	} else {	142	} else {
141	int n = 1 + fls(high);	143	int n = 1 + fls(high);
142	quot = div_u64(dividend >> n, divisor >> n);	144	quot = div_u64(dividend >> n, divisor >> n);
143		145
144	if (quot != 0)	146	if (quot != 0)
145	quot--;	147	quot--;
146	if ((dividend - quot * divisor) >= divisor)	148	if ((dividend - quot * divisor) >= divisor)
147	quot++;	149	quot++;
148	}	150	}
149		151
150	return quot;	152	return quot;
151	}	153	}
152	EXPORT_SYMBOL(div64_u64);	154	EXPORT_SYMBOL(div64_u64);
153	#endif	155	#endif
154		156
155	/**	157	/**
156	* div64_s64 - signed 64bit divide with 64bit divisor	158	* div64_s64 - signed 64bit divide with 64bit divisor
157	* @dividend: 64bit dividend	159	* @dividend: 64bit dividend
158	* @divisor: 64bit divisor	160	* @divisor: 64bit divisor
159	*/	161	*/
160	#ifndef div64_s64	162	#ifndef div64_s64
161	s64 div64_s64(s64 dividend, s64 divisor)	163	s64 div64_s64(s64 dividend, s64 divisor)
162	{	164	{
163	s64 quot, t;	165	s64 quot, t;
164		166
165	quot = div64_u64(abs(dividend), abs(divisor));	167	quot = div64_u64(abs(dividend), abs(divisor));
166	t = (dividend ^ divisor) >> 63;	168	t = (dividend ^ divisor) >> 63;
167		169
168	return (quot ^ t) - t;	170	return (quot ^ t) - t;
169	}	171	}
170	EXPORT_SYMBOL(div64_s64);	172	EXPORT_SYMBOL(div64_s64);
171	#endif	173	#endif
172		174
173	#endif /* BITS_PER_LONG == 32 */	175	#endif /* BITS_PER_LONG == 32 */
174		176
175	/*	177	/*
176	* Iterative div/mod for use when dividend is not expected to be much	178	* Iterative div/mod for use when dividend is not expected to be much
177	* bigger than divisor.	179	* bigger than divisor.
178	*/	180	*/
179	u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)	181	u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
180	{	182	{
181	return __iter_div_u64_rem(dividend, divisor, remainder);	183	return __iter_div_u64_rem(dividend, divisor, remainder);
182	}	184	}
183	EXPORT_SYMBOL(iter_div_u64_rem);	185	EXPORT_SYMBOL(iter_div_u64_rem);

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(root)/drivers/ddk/linux/div64.c – Rev 6934 → 6936