| @node machine,,syscalls,Top |
| @chapter NEC V70 Specific Functions |
| |
| The NEC V70 has machine instructions for fast IEEE floating-point |
| arithmetic, including operations normally provided by the library. |
| |
| When you use the @file{/usr/include/fastmath.h} header file, the |
| names of several library math functions are redefined to call the |
| @code{fastmath} routine (using the corresponding V70 machine instructions) |
| whenever possible. |
| |
| For example, |
| @example |
| |
| #include <fastmath.h> |
| |
| double sqsin(x) |
| double x; |
| @{ |
| return sin(x*x); |
| @} |
| |
| @end example |
| expands into the code |
| @example |
| |
| @dots{} |
| double sqsin(x) |
| double x; |
| @{ |
| return fast_sin(x*x); |
| @} |
| |
| @end example |
| |
| The library has an entry @code{fast_sin} which uses the machine |
| instruction @code{fsin.l} to perform the operation. Note that the |
| built-in instructions cannot call @code{matherr} or set @code{errno} |
| in the same way that the C coded functions do. Refer to a V70 |
| instruction manual to see how errors are generated and handled. |
| |
| Also, the library provides true @code{float} entry points. The |
| @code{fast_sinf} entry point really performs a @code{fsin.s} |
| operation. Because of this, the instructions are only useful when |
| using code compiled with an ANSI C compiler. The prototypes |
| and definitions for the floating-point versions of the math library |
| routines are only defined if compiling a module with an ANSI C |
| compiler. |
| |
| @page |
| @section Entry points |
| The functions provided by @file{fastmath.h} are |
| @example |
| |
| double fast_sin(double); /* fsin.l */ |
| double fast_cos(double); /* fcos.l */ |
| double fast_tan(double); /* ftan.l */ |
| double fast_asin(double); /* fasin.l */ |
| double fast_acos(double); /* facos.l */ |
| double fast_atan(double); /* fatan.l */ |
| double fast_sinh(double); /* fsinh.l */ |
| double fast_cosh(double); /* fcosh.l */ |
| double fast_tanh(double); /* ftanh.l */ |
| double fast_asinh(double); /* fasinh.l */ |
| double fast_acosh(double); /* facosh.l */ |
| double fast_atanh(double); /* fatanh.l */ |
| double fast_fabs(double); /* fabs.l */ |
| double fast_sqrt(double); /* fsqrt.l */ |
| double fast_exp2(double); /* fexp2.l */ |
| double fast_exp10(double); /* fexp10.l */ |
| double fast_expe(double); /* fexpe.l */ |
| double fast_log10(double); /* flog10.l */ |
| double fast_log2(double); /* flog2.l */ |
| double fast_loge(double); /* floge.l */ |
| |
| float fast_sinf(float); /* fsin.s */ |
| float fast_cosf(float); /* fcos.s */ |
| float fast_tanf(float); /* ftan.s */ |
| float fast_asinf(float); /* fasin.s */ |
| float fast_acosf(float); /* facos.s */ |
| float fast_atanf(float); /* fatan.s */ |
| float fast_sinhf(float); /* fsinh.s */ |
| float fast_coshf(float); /* fcosh.s */ |
| float fast_tanhf(float); /* ftanh.s */ |
| float fast_asinhf(float); /* fasinh.s */ |
| float fast_acoshf(float); /* facosh.s */ |
| float fast_atanhf(float); /* fatanh.s */ |
| float fast_fabsf(float); /* fabs.s */ |
| float fast_sqrtf(float); /* fsqrt.s */ |
| float fast_exp2f(float); /* fexp2.s */ |
| float fast_exp10f(float); /* fexp10.s */ |
| float fast_expef(float); /* fexpe.s */ |
| float fast_log10f(float); /* flog10.s */ |
| float fast_log2f(float); /* flog2.s */ |
| float fast_logef(float); /* floge.s */ |
| |
| @end example |
| |
| |
