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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH pow 3M "12 Jul 2006" "SunOS 5.11" "Mathematical Library Functions" .SH NAME pow, powf, powl \- power function .SH SYNOPSIS .LP .nf c99 [ \fIflag\fR... ] \fIfile\fR... \fB-lm\fR [ \fIlibrary\fR... ] #include \fBdouble\fR \fBpow\fR(\fBdouble\fR x, \fBdouble\fR y); .fi .LP .nf \fBfloat\fR \fBpowf\fR(\fBfloat\fR x, \fBfloat\fR y); .fi .LP .nf \fBlong double\fR \fBpowl\fR(\fBlong double\fR x, \fBlong double\fR y); .fi .LP .nf cc [ \fIflag\fR... ] \fIfile\fR... \fB-lm\fR [ \fIlibrary\fR... ] #include \fBdouble\fR \fBpow\fR(\fBdouble\fR x, \fBdouble\fR y); .fi .LP .nf \fBfloat\fR \fBpowf\fR(\fBfloat\fR x, \fBfloat\fR y); .fi .LP .nf \fBlong double\fR \fBpowl\fR(\fBlong double\fR x, \fBlong double\fR y); .fi .SH DESCRIPTION .sp .LP These functions compute the value of \fIx\fR raised to the power \fIy,\fR \fIx\fR^y>. If \fIx\fR is negative, \fIy\fR must be an integer value. .SH RETURN VALUES .sp .LP Upon successful completion, these functions return the value of \fIx\fR raised to the power \fIy\fR. .sp .LP For finite values of \fIx\fR < 0, and finite non-integer values of \fIy\fR, a domain error occurs and either a NaN (if representable), or an implementation-defined value is returned. .sp .LP If the correct value would cause overflow, a range error occurs and \fBpow()\fR, \fBpowf()\fR, and \fBpowl()\fR return \fBHUGE_VAL\fR, \fBHUGE_VALF\fR, and \fBHUGE_VALL\fR, respectively. .sp .LP If \fIx\fR or \fIy\fR is a NaN, a NaN is returned unless: .RS +4 .TP .ie t \(bu .el o If \fIx\fR is +1 and \fIy\fR is NaN and the application was compiled with the \fBc99\fR compiler driver and is therefore SUSv3-conforming (see \fBstandards\fR(5)), 1.0 is returned. .RE .RS +4 .TP .ie t \(bu .el o For any value of \fIx\fR (including NaN), if \fIy\fR is +0, 1.0 is returned. .RE .sp .LP For any odd integer value of \fIy\fR > 0, if \fIx\fR is \(+-0, \(+-0 is returned. .sp .LP For \fIy\fR > 0 and not an odd integer, if \fIx\fR is \(+-0, +0 is returned. .sp .LP If \fIx\fR is \(+-1 and \fIy\fR is \(+-Inf, and the application was compiled with the \fBcc\fR compiler driver, NaN is returned. If, however, the application was compiled with the \fBc99\fR compiler driver and is therefore SUSv3-conforming (see\fBstandards\fR(5)), 1.0 is returned. .sp .LP For |\fIx\fR| < 1, if \fIy\fR is \(miInf, +Inf is returned. .sp .LP For |\fIx\fR| > 1, if \fIy\fR is \(miInf, +0 is returned. .sp .LP For |\fIx\fR| < 1, if \fIy\fR is +Inf, +0 is returned. .sp .LP For |\fIx\fR| > 1, if \fIy\fR is +Inf, +Inf is returned. .sp .LP For \fIy\fR an odd integer < 0, if \fIx\fR is \(miInf, \(mi0 is returned. .sp .LP For \fIy\fR < 0 and not an odd integer, if \fIx\fR is \(miInf, +0 is returned. .sp .LP For \fIy\fR an odd integer > 0, if \fIx\fR is \(miInf, \(miInf is returned. .sp .LP For \fIy\fR > 0 and not an odd integer, if \fIx\fR is \(miInf, +Inf is returned. .sp .LP For \fIy\fR < 0, if \fIx\fR is +Inf, +0 is returned. .sp .LP For \fIy\fR > 0, if \fIx\fR is +Inf, +Inf is returned. .sp .LP For \fIy\fR an odd integer < 0, if \fIx\fR is \(+-0, a pole error occurs and \(+-\fBHUGE_VAL\fR, \(+-\fBHUGE_VALF\fR, and \(+-\fBHUGE_VALL\fR are returned for \fBpow()\fR, \fBpowf()\fR, and \fBpowl()\fR, respectively. .sp .LP For \fIy\fR < 0 and not an odd integer, if \fIx\fR is \(+-0, a pole error occurs and \fBHUGE_VAL\fR, \fBHUGE_VALF\fR, and \fBHUGE_VALL\fR are returned for \fBpow()\fR, \fBpowf()\fR, and \fBpowl()\fR, respectively. .sp .LP For exceptional cases, \fBmatherr\fR(3M) tabulates the values to be returned by \fBpow()\fR as specified by SVID3 and XPG3. .SH ERRORS .sp .LP These functions will fail if: .sp .ne 2 .mk .na \fBDomain Error\fR .ad .RS 16n .rt The value of \fIx\fR is negative and \fIy\fR is a finite non-integer. .sp If the integer expression (\fBmath_errhandling\fR & \fBMATH_ERREXCEPT\fR) is non-zero, the invalid floating-point exception is raised. .sp The \fBpow()\fR function sets \fBerrno\fR to \fBEDOM\fR if the value of \fIx\fR is negative and \fIy\fR is non-integral. .RE .sp .ne 2 .mk .na \fBPole Error\fR .ad .RS 16n .rt The value of \fIx\fR is 0 and \fIy\fR is negative. .sp If the integer expression (\fBmath_errhandling\fR & \fBMATH_ERREXCEPT\fR) is non-zero, the divide-by-zero floating-point exception is raised. .RE .sp .ne 2 .mk .na \fBRange Error\fR .ad .RS 16n .rt The result overflows. .sp If the integer expression (\fBmath_errhandling\fR & \fBMATH_ERREXCEPT\fR) is non-zero, the overflow floating-point exception is raised. .sp The \fBpow()\fR function sets \fBerrno\fR to \fBEDOM\fR if the value to be returned would cause overflow. .RE .SH USAGE .sp .LP An application wanting to check for exceptions should call \fBfeclearexcept\fR(\fBFE_ALL_EXCEPT\fR) before calling these functions. On return, if \fBfetestexcept\fR(\fBFE_INVALID\fR | \fBFE_DIVBYZERO\fR | \fBFE_OVERFLOW\fR | \fBFE_UNDERFLOW\fR) is non-zero, an exception has been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions. .sp .LP An application can also set \fBerrno\fR to 0 before calling \fBpow()\fR. On return, if \fBerrno\fR is non-zero, an error has occurred. The \fBpowf()\fR and \fBpowl()\fR functions do not set \fBerrno\fR. .SH ATTRIBUTES .sp .LP See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) . ATTRIBUTE TYPEATTRIBUTE VALUE _ Interface StabilityStandard _ MT-LevelMT-Safe .TE .SH SEE ALSO .sp .LP \fBexp\fR(3M), \fBfeclearexcept\fR(3M), \fBfetestexcept\fR(3M), \fBisnan\fR(3M), \fBmath.h\fR(3HEAD), \fBmatherr\fR(3M), \fBattributes\fR(5), \fBstandards\fR(5) .SH NOTES .sp .LP Prior to Solaris 2.6, there was a conflict between the \fBpow()\fR function in this library and the \fBpow()\fR function in the \fBlibmp\fR library. This conflict was resolved by prepending \fBmp_\fR to all functions in the \fBlibmp\fR library. See \fBmp\fR(3MP) for more information.