Commit dce1eb93 authored by Nicolas Pitre's avatar Nicolas Pitre
Browse files

__div64_32(): make it overridable at compile time 



Some architectures may want to override the default implementation
at compile time to do things inline.  For example, ARM uses a
non-standard calling convention for better efficiency in this case.

Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
parent f682b27c

include/asm-generic/div64.h

+2 −0
Original line number Diff line number Diff line
@@ -194,7 +194,9 @@ static inline uint64_t __arch_xprod_64(const uint64_t m, uint64_t n, bool bias) 
}

#endif



#ifndef __div64_32

extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);

#endif



/* The unnecessary pointer compare is there

 * to check for type safety (n must be 64bit)

lib/div64.c

+4 −2
Original line number Diff line number Diff line
@@ -13,7 +13,8 @@ 
 *

 * 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.

 * 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 <linux/export.h>
@@ -23,6 +24,7 @@ 
/* 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;
@@ -55,8 +57,8 @@ uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base) 
	*n = res;

	return rem;

}



EXPORT_SYMBOL(__div64_32);

#endif



#ifndef div_s64_rem

s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)

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