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Diffstat (limited to 'lib/pure/fenv.nim')
| -rw-r--r-- | lib/pure/fenv.nim | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/lib/pure/fenv.nim b/lib/pure/fenv.nim new file mode 100644 index 000000000..1d96fd6be --- /dev/null +++ b/lib/pure/fenv.nim @@ -0,0 +1,182 @@ +# +# +# Nim's Runtime Library +# (c) Copyright 2015 Andreas Rumpf +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +## Floating-point environment. Handling of floating-point rounding and +## exceptions (overflow, division by zero, etc.). +## The types, vars and procs are bindings for the C standard library +## [<fenv.h>](https://en.cppreference.com/w/c/numeric/fenv) header. + +when defined(posix) and not defined(genode) and not defined(macosx): + {.passl: "-lm".} + +var + FE_DIVBYZERO* {.importc, header: "<fenv.h>".}: cint + ## division by zero + FE_INEXACT* {.importc, header: "<fenv.h>".}: cint + ## inexact result + FE_INVALID* {.importc, header: "<fenv.h>".}: cint + ## invalid operation + FE_OVERFLOW* {.importc, header: "<fenv.h>".}: cint + ## result not representable due to overflow + FE_UNDERFLOW* {.importc, header: "<fenv.h>".}: cint + ## result not representable due to underflow + FE_ALL_EXCEPT* {.importc, header: "<fenv.h>".}: cint + ## bitwise OR of all supported exceptions + FE_DOWNWARD* {.importc, header: "<fenv.h>".}: cint + ## round toward -Inf + FE_TONEAREST* {.importc, header: "<fenv.h>".}: cint + ## round to nearest + FE_TOWARDZERO* {.importc, header: "<fenv.h>".}: cint + ## round toward 0 + FE_UPWARD* {.importc, header: "<fenv.h>".}: cint + ## round toward +Inf + FE_DFL_ENV* {.importc, header: "<fenv.h>".}: cint + ## macro of type pointer to `fenv_t` to be used as the argument + ## to functions taking an argument of type `fenv_t`; in this + ## case the default environment will be used + +type + Tfenv* {.importc: "fenv_t", header: "<fenv.h>", final, pure.} = + object ## Represents the entire floating-point environment. The + ## floating-point environment refers collectively to any + ## floating-point status flags and control modes supported + ## by the implementation. + Tfexcept* {.importc: "fexcept_t", header: "<fenv.h>", final, pure.} = + object ## Represents the floating-point status flags collectively, + ## including any status the implementation associates with the + ## flags. A floating-point status flag is a system variable + ## whose value is set (but never cleared) when a floating-point + ## exception is raised, which occurs as a side effect of + ## exceptional floating-point arithmetic to provide auxiliary + ## information. A floating-point control mode is a system variable + ## whose value may be set by the user to affect the subsequent + ## behavior of floating-point arithmetic. + +proc feclearexcept*(excepts: cint): cint {.importc, header: "<fenv.h>".} + ## Clear the supported exceptions represented by `excepts`. + +proc fegetexceptflag*(flagp: ptr Tfexcept, excepts: cint): cint {. + importc, header: "<fenv.h>".} + ## Store implementation-defined representation of the exception flags + ## indicated by `excepts` in the object pointed to by `flagp`. + +proc feraiseexcept*(excepts: cint): cint {.importc, header: "<fenv.h>".} + ## Raise the supported exceptions represented by `excepts`. + +proc fesetexceptflag*(flagp: ptr Tfexcept, excepts: cint): cint {. + importc, header: "<fenv.h>".} + ## Set complete status for exceptions indicated by `excepts` according to + ## the representation in the object pointed to by `flagp`. + +proc fetestexcept*(excepts: cint): cint {.importc, header: "<fenv.h>".} + ## Determine which of subset of the exceptions specified by `excepts` are + ## currently set. + +proc fegetround*(): cint {.importc, header: "<fenv.h>".} + ## Get current rounding direction. + +proc fesetround*(roundingDirection: cint): cint {.importc, header: "<fenv.h>".} + ## Establish the rounding direction represented by `roundingDirection`. + +proc fegetenv*(envp: ptr Tfenv): cint {.importc, header: "<fenv.h>".} + ## Store the current floating-point environment in the object pointed + ## to by `envp`. + +proc feholdexcept*(envp: ptr Tfenv): cint {.importc, header: "<fenv.h>".} + ## Save the current environment in the object pointed to by `envp`, clear + ## exception flags and install a non-stop mode (if available) for all + ## exceptions. + +proc fesetenv*(a1: ptr Tfenv): cint {.importc, header: "<fenv.h>".} + ## Establish the floating-point environment represented by the object + ## pointed to by `envp`. + +proc feupdateenv*(envp: ptr Tfenv): cint {.importc, header: "<fenv.h>".} + ## Save current exceptions in temporary storage, install environment + ## represented by object pointed to by `envp` and raise exceptions + ## according to saved exceptions. + +const + FLT_RADIX = 2 ## the radix of the exponent representation + + FLT_MANT_DIG = 24 ## the number of base FLT_RADIX digits in the mantissa part of a float + FLT_DIG = 6 ## the number of digits of precision of a float + FLT_MIN_EXP = -125 ## the minimum value of base FLT_RADIX in the exponent part of a float + FLT_MAX_EXP = 128 ## the maximum value of base FLT_RADIX in the exponent part of a float + FLT_MIN_10_EXP = -37 ## the minimum value in base 10 of the exponent part of a float + FLT_MAX_10_EXP = 38 ## the maximum value in base 10 of the exponent part of a float + FLT_MIN = 1.17549435e-38'f32 ## the minimum value of a float + FLT_MAX = 3.40282347e+38'f32 ## the maximum value of a float + FLT_EPSILON = 1.19209290e-07'f32 ## the difference between 1 and the least value greater than 1 of a float + + DBL_MANT_DIG = 53 ## the number of base FLT_RADIX digits in the mantissa part of a double + DBL_DIG = 15 ## the number of digits of precision of a double + DBL_MIN_EXP = -1021 ## the minimum value of base FLT_RADIX in the exponent part of a double + DBL_MAX_EXP = 1024 ## the maximum value of base FLT_RADIX in the exponent part of a double + DBL_MIN_10_EXP = -307 ## the minimum value in base 10 of the exponent part of a double + DBL_MAX_10_EXP = 308 ## the maximum value in base 10 of the exponent part of a double + DBL_MIN = 2.2250738585072014E-308 ## the minimal value of a double + DBL_MAX = 1.7976931348623157E+308 ## the minimal value of a double + DBL_EPSILON = 2.2204460492503131E-16 ## the difference between 1 and the least value greater than 1 of a double + +template fpRadix*: int = FLT_RADIX + ## The (integer) value of the radix used to represent any floating + ## point type on the architecture used to build the program. + +template mantissaDigits*(T: typedesc[float32]): int = FLT_MANT_DIG + ## Number of digits (in base `floatingPointRadix`) in the mantissa + ## of 32-bit floating-point numbers. +template digits*(T: typedesc[float32]): int = FLT_DIG + ## Number of decimal digits that can be represented in a + ## 32-bit floating-point type without losing precision. +template minExponent*(T: typedesc[float32]): int = FLT_MIN_EXP + ## Minimum (negative) exponent for 32-bit floating-point numbers. +template maxExponent*(T: typedesc[float32]): int = FLT_MAX_EXP + ## Maximum (positive) exponent for 32-bit floating-point numbers. +template min10Exponent*(T: typedesc[float32]): int = FLT_MIN_10_EXP + ## Minimum (negative) exponent in base 10 for 32-bit floating-point + ## numbers. +template max10Exponent*(T: typedesc[float32]): int = FLT_MAX_10_EXP + ## Maximum (positive) exponent in base 10 for 32-bit floating-point + ## numbers. +template minimumPositiveValue*(T: typedesc[float32]): float32 = FLT_MIN + ## The smallest positive (nonzero) number that can be represented in a + ## 32-bit floating-point type. +template maximumPositiveValue*(T: typedesc[float32]): float32 = FLT_MAX + ## The largest positive number that can be represented in a 32-bit + ## floating-point type. +template epsilon*(T: typedesc[float32]): float32 = FLT_EPSILON + ## The difference between 1.0 and the smallest number greater than + ## 1.0 that can be represented in a 32-bit floating-point type. + +template mantissaDigits*(T: typedesc[float64]): int = DBL_MANT_DIG + ## Number of digits (in base `floatingPointRadix`) in the mantissa + ## of 64-bit floating-point numbers. +template digits*(T: typedesc[float64]): int = DBL_DIG + ## Number of decimal digits that can be represented in a + ## 64-bit floating-point type without losing precision. +template minExponent*(T: typedesc[float64]): int = DBL_MIN_EXP + ## Minimum (negative) exponent for 64-bit floating-point numbers. +template maxExponent*(T: typedesc[float64]): int = DBL_MAX_EXP + ## Maximum (positive) exponent for 64-bit floating-point numbers. +template min10Exponent*(T: typedesc[float64]): int = DBL_MIN_10_EXP + ## Minimum (negative) exponent in base 10 for 64-bit floating-point + ## numbers. +template max10Exponent*(T: typedesc[float64]): int = DBL_MAX_10_EXP + ## Maximum (positive) exponent in base 10 for 64-bit floating-point + ## numbers. +template minimumPositiveValue*(T: typedesc[float64]): float64 = DBL_MIN + ## The smallest positive (nonzero) number that can be represented in a + ## 64-bit floating-point type. +template maximumPositiveValue*(T: typedesc[float64]): float64 = DBL_MAX + ## The largest positive number that can be represented in a 64-bit + ## floating-point type. +template epsilon*(T: typedesc[float64]): float64 = DBL_EPSILON + ## The difference between 1.0 and the smallest number greater than + ## 1.0 that can be represented in a 64-bit floating-point type. |