MPFRとは 意味・読み方・使い方

GNU MPFR is a portable C library for arbitrary-precision binary floating-point computation with correct rounding, based on GNU Multi-Precision Library. The computation is both efficient and has a well-defined semantics. It copies the ideas from the ANSI/IEEE-754 standard for fixed-precision floating-point arithmetic. More precisely, its main features are:

• Support for special numbers: signed zeros (-0), infinities and not-a-number (a single NaN is currently supported).
• Each number has its own precision (in bits since MPFR uses radix 2). The floating-point results are correctly rounded to the precision of the target variable, in any of the four IEEE-754 rounding modes.
• Supported functions: MPFR implements all mathematical functions from C99: the logarithm and exponential in natural base, base 2 and base 10, the log(1+x) and exp(x)-1 functions (log1p and expm1), the six trigonometric and hyperbolic functions and their inverses, the gamma, zeta and error functions, the arithmetic geometric mean, the power (x^y) function. All those functions are correctly rounded over their complete range.
• Subnormals are not supported, but can be emulated with the mpfr_subnormalize function.