| 1 | @node machine,,syscalls,Top |
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| 2 | @chapter NEC V70 Specific Functions |
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| 3 | |
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| 4 | The NEC V70 has machine instructions for fast IEEE floating-point |
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| 5 | arithmetic, including operations normally provided by the library. |
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| 6 | |
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| 7 | When you use the @file{/usr/include/fastmath.h} header file, the |
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| 8 | names of several library math functions are redefined to call the |
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| 9 | @code{fastmath} routine (using the corresponding V70 machine instructions) |
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| 10 | whenever possible. |
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| 11 | |
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| 12 | For example, |
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| 13 | @example |
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| 14 | |
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| 15 | #include <fastmath.h> |
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| 16 | |
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| 17 | double sqsin(x) |
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| 18 | double x; |
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| 19 | @{ |
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| 20 | return sin(x*x); |
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| 21 | @} |
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| 22 | |
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| 23 | @end example |
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| 24 | expands into the code |
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| 25 | @example |
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| 26 | |
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| 27 | @dots{} |
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| 28 | double sqsin(x) |
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| 29 | double x; |
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| 30 | @{ |
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| 31 | return fast_sin(x*x); |
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| 32 | @} |
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| 33 | |
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| 34 | @end example |
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| 35 | |
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| 36 | The library has an entry @code{fast_sin} which uses the machine |
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| 37 | instruction @code{fsin.l} to perform the operation. Note that the |
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| 38 | built-in instructions cannot call @code{matherr} or set @code{errno} |
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| 39 | in the same way that the C coded functions do. Refer to a V70 |
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| 40 | instruction manual to see how errors are generated and handled. |
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| 41 | |
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| 42 | Also, the library provides true @code{float} entry points. The |
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| 43 | @code{fast_sinf} entry point really performs a @code{fsin.s} |
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| 44 | operation. Because of this, the instructions are only useful when |
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| 45 | using code compiled with an ANSI C compiler. The prototypes |
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| 46 | and definitions for the floating-point versions of the math library |
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| 47 | routines are only defined if compiling a module with an ANSI C |
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| 48 | compiler. |
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| 49 | |
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| 50 | @page |
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| 51 | @section Entry points |
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| 52 | The functions provided by @file{fastmath.h} are |
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| 53 | @example |
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| 54 | |
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| 55 | double fast_sin(double); /* fsin.l */ |
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| 56 | double fast_cos(double); /* fcos.l */ |
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| 57 | double fast_tan(double); /* ftan.l */ |
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| 58 | double fast_asin(double); /* fasin.l */ |
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| 59 | double fast_acos(double); /* facos.l */ |
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| 60 | double fast_atan(double); /* fatan.l */ |
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| 61 | double fast_sinh(double); /* fsinh.l */ |
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| 62 | double fast_cosh(double); /* fcosh.l */ |
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| 63 | double fast_tanh(double); /* ftanh.l */ |
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| 64 | double fast_asinh(double); /* fasinh.l */ |
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| 65 | double fast_acosh(double); /* facosh.l */ |
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| 66 | double fast_atanh(double); /* fatanh.l */ |
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| 67 | double fast_fabs(double); /* fabs.l */ |
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| 68 | double fast_sqrt(double); /* fsqrt.l */ |
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| 69 | double fast_exp2(double); /* fexp2.l */ |
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| 70 | double fast_exp10(double); /* fexp10.l */ |
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| 71 | double fast_expe(double); /* fexpe.l */ |
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| 72 | double fast_log10(double); /* flog10.l */ |
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| 73 | double fast_log2(double); /* flog2.l */ |
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| 74 | double fast_loge(double); /* floge.l */ |
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| 75 | |
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| 76 | float fast_sinf(float); /* fsin.s */ |
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| 77 | float fast_cosf(float); /* fcos.s */ |
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| 78 | float fast_tanf(float); /* ftan.s */ |
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| 79 | float fast_asinf(float); /* fasin.s */ |
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| 80 | float fast_acosf(float); /* facos.s */ |
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| 81 | float fast_atanf(float); /* fatan.s */ |
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| 82 | float fast_sinhf(float); /* fsinh.s */ |
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| 83 | float fast_coshf(float); /* fcosh.s */ |
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| 84 | float fast_tanhf(float); /* ftanh.s */ |
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| 85 | float fast_asinhf(float); /* fasinh.s */ |
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| 86 | float fast_acoshf(float); /* facosh.s */ |
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| 87 | float fast_atanhf(float); /* fatanh.s */ |
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| 88 | float fast_fabsf(float); /* fabs.s */ |
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| 89 | float fast_sqrtf(float); /* fsqrt.s */ |
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| 90 | float fast_exp2f(float); /* fexp2.s */ |
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| 91 | float fast_exp10f(float); /* fexp10.s */ |
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| 92 | float fast_expef(float); /* fexpe.s */ |
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| 93 | float fast_log10f(float); /* flog10.s */ |
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| 94 | float fast_log2f(float); /* flog2.s */ |
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| 95 | float fast_logef(float); /* floge.s */ |
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| 96 | |
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| 97 | @end example |
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| 98 | |
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| 99 | |
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