logd2.h

Newlib 嵌入式 C库 标准实现代码

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#ifdef __SPU__
#ifndef _LOGD2_H_
#define _LOGD2_H_	1

#include <spu_intrinsics.h>
#include "simdmath.h"
#include "log2d2.h"


/*
 * FUNCTION
 *	vector double _logd2(vector double x)
 *
 * DESCRIPTION
 *	The _logd2 function computes the natural log for each double word
 *      element of the input x. _logd2 is computed using log2d2 as follows:
 *
 *	logd2(x) = log2d2(x) / log2d2(e) = log2d2(x) * logd2(2)
 *
 */
static __inline vector double _logd2(vector double x)
{
  return (spu_mul(_log2d2(x), spu_splats(SM_LN2)));
}

#endif /* _LOGD2_H_ */
#endif /* __SPU__ */