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yaml
---
r: 95642
b: refs/heads/master
c: 2418f4f
h: refs/heads/master
v: v3
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Roman Zippel authored and Linus Torvalds committed May 1, 2008
1 parent dcb5d16 commit 8808f58
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Showing 4 changed files with 114 additions and 3 deletions.
2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: adafbedf0c31ae1cde62035c82857f5e376af553
refs/heads/master: 2418f4f28f8467b92a6177af32d05737ebf6206c
20 changes: 20 additions & 0 deletions trunk/include/asm-x86/div64.h
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Expand Up @@ -51,6 +51,26 @@ static inline long div_ll_X_l_rem(long long divs, long div, long *rem)

}

static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
{
union {
u64 v64;
u32 v32[2];
} d = { dividend };
u32 upper;

upper = d.v32[1];
d.v32[1] = 0;
if (upper >= divisor) {
d.v32[1] = upper / divisor;
upper %= divisor;
}
asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
"rm" (divisor), "0" (d.v32[0]), "1" (upper));
return d.v64;
}
#define div_u64_rem div_u64_rem

extern uint64_t div64_64(uint64_t dividend, uint64_t divisor);

#else
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72 changes: 72 additions & 0 deletions trunk/include/linux/math64.h
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@@ -0,0 +1,72 @@
#ifndef _LINUX_MATH64_H
#define _LINUX_MATH64_H

#include <linux/types.h>
#include <asm/div64.h>

#if BITS_PER_LONG == 64

/**
* div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
*
* This is commonly provided by 32bit archs to provide an optimized 64bit
* divide.
*/
static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
{
*remainder = dividend % divisor;
return dividend / divisor;
}

/**
* div_s64_rem - signed 64bit divide with 32bit divisor with remainder
*/
static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
{
*remainder = dividend % divisor;
return dividend / divisor;
}

#elif BITS_PER_LONG == 32

#ifndef div_u64_rem
static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
{
*remainder = do_div(dividend, divisor);
return dividend;
}
#endif

#ifndef div_s64_rem
extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
#endif

#endif /* BITS_PER_LONG */

/**
* div_u64 - unsigned 64bit divide with 32bit divisor
*
* This is the most common 64bit divide and should be used if possible,
* as many 32bit archs can optimize this variant better than a full 64bit
* divide.
*/
#ifndef div_u64
static inline u64 div_u64(u64 dividend, u32 divisor)
{
u32 remainder;
return div_u64_rem(dividend, divisor, &remainder);
}
#endif

/**
* div_s64 - signed 64bit divide with 32bit divisor
*/
#ifndef div_s64
static inline s64 div_s64(s64 dividend, s32 divisor)
{
s32 remainder;
return div_s64_rem(dividend, divisor, &remainder);
}
#endif

#endif /* _LINUX_MATH64_H */
23 changes: 21 additions & 2 deletions trunk/lib/div64.c
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Expand Up @@ -16,9 +16,8 @@
* assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S.
*/

#include <linux/types.h>
#include <linux/module.h>
#include <asm/div64.h>
#include <linux/math64.h>

/* Not needed on 64bit architectures */
#if BITS_PER_LONG == 32
Expand Down Expand Up @@ -58,6 +57,26 @@ uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)

EXPORT_SYMBOL(__div64_32);

#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

/* 64bit divisor, dividend and result. dynamic precision */
uint64_t div64_64(uint64_t dividend, uint64_t divisor)
{
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