Move floating point rounding and exceptions handling to math

(it's C99 as well, not just POSIX)

1 files changed, 43 insertions, 0 deletions

diff --git a/lib/pure/math.nim b/lib/pure/math.nim
index 2f7a696b9..cc774539d 100644
--- a/lib/pure/math.nim
+++ b/lib/pure/math.nim
@@ -40,6 +40,19 @@ const
                                            ## after the decimal point 
                                            ## for Nimrod's ``float`` type.
 
+var
+  FE_DIVBYZERO* {.importc, header: "<fenv.h>".}: cint
+  FE_INEXACT* {.importc, header: "<fenv.h>".}: cint
+  FE_INVALID* {.importc, header: "<fenv.h>".}: cint
+  FE_OVERFLOW* {.importc, header: "<fenv.h>".}: cint
+  FE_UNDERFLOW* {.importc, header: "<fenv.h>".}: cint
+  FE_ALL_EXCEPT* {.importc, header: "<fenv.h>".}: cint
+  FE_DOWNWARD* {.importc, header: "<fenv.h>".}: cint
+  FE_TONEAREST* {.importc, header: "<fenv.h>".}: cint
+  FE_TOWARDZERO* {.importc, header: "<fenv.h>".}: cint
+  FE_UPWARD* {.importc, header: "<fenv.h>".}: cint
+  FE_DFL_ENV* {.importc, header: "<fenv.h>".}: cint
+
 type
   TFloatClass* = enum ## describes the class a floating point value belongs to.
                       ## This is the type that is returned by `classify`.
@@ -51,6 +64,22 @@ type
     fcInf,       ## value is positive infinity
     fcNegInf     ## value is negative infinity
 
+  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 classify*(x: float): TFloatClass = 
   ## classifies a floating point value. Returns `x`'s class as specified by
   ## `TFloatClass`.
@@ -321,6 +350,20 @@ proc standardDeviation*(s: TRunningStat): float =
   ## computes the current standard deviation of `s`
   result = sqrt(variance(s))
 
+proc feclearexcept*(a1: cint): cint {.importc, header: "<fenv.h>".}
+proc fegetexceptflag*(a1: ptr Tfexcept, a2: cint): cint {.
+  importc, header: "<fenv.h>".}
+proc feraiseexcept*(a1: cint): cint {.importc, header: "<fenv.h>".}
+proc fesetexceptflag*(a1: ptr Tfexcept, a2: cint): cint {.
+  importc, header: "<fenv.h>".}
+proc fetestexcept*(a1: cint): cint {.importc, header: "<fenv.h>".}
+proc fegetround*(): cint {.importc, header: "<fenv.h>".}
+proc fesetround*(a1: cint): cint {.importc, header: "<fenv.h>".}
+proc fegetenv*(a1: ptr Tfenv): cint {.importc, header: "<fenv.h>".}
+proc feholdexcept*(a1: ptr Tfenv): cint {.importc, header: "<fenv.h>".}
+proc fesetenv*(a1: ptr Tfenv): cint {.importc, header: "<fenv.h>".}
+proc feupdateenv*(a1: ptr Tfenv): cint {.importc, header: "<fenv.h>".}
+
 {.pop.}
 {.pop.}