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diff --git a/man3p/fdim.3p b/man3p/fdim.3p new file mode 100644 index 000000000..5aef036d2 --- /dev/null +++ b/man3p/fdim.3p @@ -0,0 +1,111 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "FDIM" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" fdim +.SH NAME +fdim, fdimf, fdiml \- compute positive difference between two floating-point +numbers +.SH SYNOPSIS +.LP +\fB#include <math.h> +.br +.sp +double fdim(double\fP \fIx\fP\fB, double\fP \fIy\fP\fB); +.br +float fdimf(float\fP \fIx\fP\fB, float\fP \fIy\fP\fB); +.br +long double fdiml(long double\fP \fIx\fP\fB, long double\fP \fIy\fP\fB); +.br +\fP +.SH DESCRIPTION +.LP +These functions shall determine the positive difference between their +arguments. If \fIx\fP is greater than \fIy\fP, \fIx\fP- +\fIy\fP is returned. If \fIx\fP is less than or equal to \fIy\fP, ++0 is returned. +.LP +An application wishing to check for error situations should set \fIerrno\fP +to zero and call +\fIfeclearexcept\fP(FE_ALL_EXCEPT) before calling these functions. +On return, if \fIerrno\fP is non-zero or +\fIfetestexcept\fP(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) +is non-zero, an error has occurred. +.SH RETURN VALUE +.LP +Upon successful completion, these functions shall return the positive +difference value. +.LP +If \fIx\fP- \fIy\fP is positive and overflows, a range error shall +occur and \fIfdim\fP(), \fIfdimf\fP(), and \fIfdiml\fP() +shall return the value of the macro HUGE_VAL, HUGE_VALF, and HUGE_VALL, +respectively. +.LP +If \fIx\fP- \fIy\fP is positive and underflows, a range error may +occur, and either ( \fIx\fP- \fIy\fP) (if representable), +\ or 0.0 (if supported), or an implementation-defined value +shall be returned. +.LP +If +\fIx\fP or \fIy\fP is NaN, a NaN shall be returned. +.SH ERRORS +.LP +The \fIfdim\fP() function shall fail if: +.TP 7 +Range\ Error +The result overflows. +.LP +If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, +then \fIerrno\fP shall be set to [ERANGE]. If the +integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, +then the overflow floating-point exception shall be +raised. +.sp +.LP +The \fIfdim\fP() function may fail if: +.TP 7 +Range\ Error +The result underflows. +.LP +If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, +then \fIerrno\fP shall be set to [ERANGE]. If the +integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, +then the underflow floating-point exception shall be +raised. +.sp +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.LP +None. +.SH APPLICATION USAGE +.LP +On implementations supporting IEEE\ Std\ 754-1985, \fIx\fP- \fIy\fP +cannot underflow, and hence the 0.0 return value +is shaded as an extension for implementations supporting the XSI extension +rather than an MX extension. +.LP +On error, the expressions (math_errhandling & MATH_ERRNO) and (math_errhandling +& MATH_ERREXCEPT) are independent of +each other, but at least one of them must be non-zero. +.SH RATIONALE +.LP +None. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIfeclearexcept\fP() , \fIfetestexcept\fP() , \fIfmax\fP() , \fIfmin\fP() +, the Base Definitions volume of +IEEE\ Std\ 1003.1-2001, Section 4.18, Treatment of Error Conditions +for +Mathematical Functions, \fI<math.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |