cregit-Linux how code gets into the kernel

Release 4.7 include/linux/reciprocal_div.h

Directory: include/linux
#ifndef _LINUX_RECIPROCAL_DIV_H

#define _LINUX_RECIPROCAL_DIV_H

#include <linux/types.h>

/*
 * This algorithm is based on the paper "Division by Invariant
 * Integers Using Multiplication" by Torbjörn Granlund and Peter
 * L. Montgomery.
 *
 * The assembler implementation from Agner Fog, which this code is
 * based on, can be found here:
 * http://www.agner.org/optimize/asmlib.zip
 *
 * This optimization for A/B is helpful if the divisor B is mostly
 * runtime invariant. The reciprocal of B is calculated in the
 * slow-path with reciprocal_value(). The fast-path can then just use
 * a much faster multiplication operation with a variable dividend A
 * to calculate the division A/B.
 */


struct reciprocal_value {
	
u32 m;
	

u8 sh1, sh2;
};

struct reciprocal_value reciprocal_value(u32 d);


static inline u32 reciprocal_divide(u32 a, struct reciprocal_value R) { u32 t = (u32)(((u64)a * R.m) >> 32); return (t + ((a - t) >> R.sh1)) >> R.sh2; }

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PersonTokensPropCommitsCommitProp
hannes frederic sowahannes frederic sowa3053.57%150.00%
eric dumazeteric dumazet2646.43%150.00%
Total56100.00%2100.00%

#endif /* _LINUX_RECIPROCAL_DIV_H */

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hannes frederic sowahannes frederic sowa4752.22%150.00%
eric dumazeteric dumazet4347.78%150.00%
Total90100.00%2100.00%
Directory: include/linux
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