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Diffstat (limited to 'manual/arith.texi')
| -rw-r--r-- | manual/arith.texi | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/manual/arith.texi b/manual/arith.texi index f35c3cd9f8..dec12a06ae 100644 --- a/manual/arith.texi +++ b/manual/arith.texi @@ -1495,6 +1495,37 @@ result can actually be represented as an @code{int}---for very large numbers, this is impossible. The functions listed here return the result as a @code{double} instead to get around this problem. +The @code{fromfp} functions use the following macros, from TS +18661-1:2014, to specify the direction of rounding. These correspond +to the rounding directions defined in IEEE 754-2008. + +@vtable @code +@comment math.h +@comment ISO +@item FP_INT_UPWARD +Round toward @math{+@infinity{}}. + +@comment math.h +@comment ISO +@item FP_INT_DOWNWARD +Round toward @math{-@infinity{}}. + +@comment math.h +@comment ISO +@item FP_INT_TOWARDZERO +Round toward zero. + +@comment math.h +@comment ISO +@item FP_INT_TONEARESTFROMZERO +Round to nearest, ties round away from zero. + +@comment math.h +@comment ISO +@item FP_INT_TONEAREST +Round to nearest, ties round to even. +@end vtable + @comment math.h @comment ISO @deftypefun double ceil (double @var{x}) @@ -1660,6 +1691,56 @@ These functions are just like @code{round}, but they return a @code{long long int} instead of a floating-point number. @end deftypefun +@comment math.h +@comment ISO +@deftypefun intmax_t fromfp (double @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx intmax_t fromfpf (float @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx intmax_t fromfpl (long double @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx uintmax_t ufromfp (double @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx uintmax_t ufromfpf (float @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx uintmax_t ufromfpl (long double @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx intmax_t fromfpx (double @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx intmax_t fromfpxf (float @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx intmax_t fromfpxl (long double @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx uintmax_t ufromfpx (double @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx uintmax_t ufromfpxf (float @var{x}, int @var{round}, unsigned int @var{width}) +@comment math.h +@comment ISO +@deftypefunx uintmax_t ufromfpxl (long double @var{x}, int @var{round}, unsigned int @var{width}) +@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}} +These functions, from TS 18661-1:2014, convert a floating-point number +to an integer according to the rounding direction @var{round} (one of +the @code{FP_INT_*} macros). If the integer is outside the range of a +signed or unsigned (depending on the return type of the function) type +of width @var{width} bits (or outside the range of the return type, if +@var{width} is larger), or if @var{x} is infinite or NaN, or if +@var{width} is zero, a domain error occurs and an unspecified value is +returned. The functions with an @samp{x} in their names raise the +inexact exception when a domain error does not occur and the argument +is not an integer; the other functions do not raise the inexact +exception. +@end deftypefun + @comment math.h @comment ISO |