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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2015-11-02 13:02:46 -0500 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2015-11-16 14:42:12 -0500 |
| commit | dce1eb93b19b2a1a441708f51c97c4a554054d00 (patch) | |
| tree | 584554913e7eae7f3ab7686862fac8c59eaf0394 | |
| parent | f682b27c57aec2f0ca8927f9bb7c267c6165ad5a (diff) | |
| download | lwn-dce1eb93b19b2a1a441708f51c97c4a554054d00.tar.gz lwn-dce1eb93b19b2a1a441708f51c97c4a554054d00.zip | |
__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: Nicolas Pitre <nico@linaro.org>
| -rw-r--r-- | include/asm-generic/div64.h | 2 | ||||
| -rw-r--r-- | lib/div64.c | 6 |
2 files changed, 6 insertions, 2 deletions
diff --git a/include/asm-generic/div64.h b/include/asm-generic/div64.h index 408856a9aba1..163f77999ea4 100644 --- a/include/asm-generic/div64.h +++ b/include/asm-generic/div64.h @@ -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) diff --git a/lib/div64.c b/lib/div64.c index 62a698a432bc..7f345259c32f 100644 --- a/lib/div64.c +++ b/lib/div64.c @@ -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) |