mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-12 11:29:30 +00:00
100 lines
3.0 KiB
TeX
100 lines
3.0 KiB
TeX
|
@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
|
||
|
|
|
||
|
|
|