41 lines
1.1 KiB
C
41 lines
1.1 KiB
C
#ifndef _LINUX_HELPER_MACROS_H_
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#define _LINUX_HELPER_MACROS_H_
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#define __find_closest(x, a, as, op) \
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({ \
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typeof(as) __fc_i, __fc_as = (as) - 1; \
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typeof(x) __fc_x = (x); \
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typeof(*a) const *__fc_a = (a); \
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for (__fc_i = 0; __fc_i < __fc_as; __fc_i++) { \
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if (__fc_x op DIV_ROUND_CLOSEST(__fc_a[__fc_i] + \
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__fc_a[__fc_i + 1], 2)) \
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break; \
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} \
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(__fc_i); \
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})
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/**
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* find_closest - locate the closest element in a sorted array
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* @x: The reference value.
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* @a: The array in which to look for the closest element. Must be sorted
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* in ascending order.
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* @as: Size of 'a'.
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*
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* Returns the index of the element closest to 'x'.
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*/
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#define find_closest(x, a, as) __find_closest(x, a, as, <=)
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/**
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* find_closest_descending - locate the closest element in a sorted array
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* @x: The reference value.
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* @a: The array in which to look for the closest element. Must be sorted
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* in descending order.
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* @as: Size of 'a'.
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*
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* Similar to find_closest() but 'a' is expected to be sorted in descending
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* order.
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*/
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#define find_closest_descending(x, a, as) __find_closest(x, a, as, >=)
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#endif
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