diff options
Diffstat (limited to 'newlib/libm/common/s_isnan.c')
| -rw-r--r-- | newlib/libm/common/s_isnan.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/newlib/libm/common/s_isnan.c b/newlib/libm/common/s_isnan.c index 3ce5aa669..64deacd66 100644 --- a/newlib/libm/common/s_isnan.c +++ b/newlib/libm/common/s_isnan.c @@ -53,7 +53,7 @@ ANSI_SYNOPSIS int isnormal(real-floating <[x]>); [Archaic SUSv2 functions:] - #include <ieeefp.h> + #include <math.h> int isnan(double <[arg]>); int isinf(double <[arg]>); int finite(double <[arg]>); @@ -142,7 +142,7 @@ o- and <<isinf>> are macros that operate on multiple types of floating-point. The SUSv2 standard declares <<isnan>> as a function taking double. Newlib has decided to declare - them both as macros in math.h and as functions in ieeefp.h to + them both as functions and as macros in math.h to maintain backward compatibility. RETURNS @@ -154,9 +154,11 @@ The isnan macro returns nonzero if <[x]> is an NaN, else 0.@* The isnormal macro returns nonzero if <[x]> has a normal value, else 0. PORTABILITY -math.h macros are C99, POSIX. +math.h macros are C99, POSIX.1-2001. -ieeefp.h funtions are outdated and should be avoided. +The functions originate from BSD; isnan was listed in the X/Open +Portability Guide and Single Unix Specification, but was dropped when +the macro was standardized in POSIX.1-2001. QUICKREF isnan - pure @@ -179,8 +181,8 @@ QUICKREF * The C99 standard dictates that isnan is a macro taking * multiple floating-point types while the SUSv2 standard * notes it is a function taking a double argument. Newlib - * has chosen to implement it as a macro in <math.h> and - * declare it as a function in <ieeefp.h>. + * has chosen to declare it both as a function and as a macro in + * <math.h> for compatibility. */ #include "fdlibm.h" |