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HP-UX Reference > Sscalb(3M)HP-UX 11i Version 3: February 2007 |
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NAMEscalb(), scalbf(), scalbl(), scalbw(), scalbq() — scale exponent of a radix-independent floating-point number DESCRIPTIONThe scalb() function returns x * ry, where r is the radix of the machine's floating-point arithmetic. The radix r is 2 on all PA-RISC and Integrity servers. Integrity Server Onlyscalbf() is a float version of scalb(); it takes float arguments and returns a float result. scalbl() is a long double version of scalb(); it takes long double arguments and returns a long double result. scalbw() is an extended version of scalb(); it takes extended arguments and returns an extended result. scalbq() is equivalent to scalbl() on HP-UX systems. USAGETo use these functions, compile either with the default -Ae option or with the -Aa and -D_HPUX_SOURCE options. To use (for Integrity servers) scalbw() or scalbq(), compile also with the -fpwidetypes option. Make sure your program includes <math.h>. Link in the math library by specifying -lm on the compiler or linker command line. RETURN VALUEscalb(-x, y) and -scalb(x, y) are equivalent. If y is ±0, scalb() returns x. If x is +0 and y is +INFINITY, scalb() returns a NaN and raises the invalid exception. If x is +0 and y is an integer less than +INFINITY, scalb() returns +0. If x is +INFINITY and y is an integer greater than -INFINITY, scalb() returns +INFINITY. If x is finite and positive-signed and y is -INFINITY, scalb() returns +0. If x is positive and y is +INFINITY, scalb() returns +INFINITY. If x is +INFINITY and y is -INFINITY, scalb() returns a NaN. If x or y is NaN, scalb() returns a NaN. scalb() returns a properly signed infinity (equal to ±HUGE_VAL) (equal to +-HUGE_VAL) in lieu of a value whose magnitude is too large, and raises the overflow and inexact exceptions. scalb() raises the underflow and inexact exceptions whenever a result is tiny (essentially denormal or zero) and thereby suffers loss of accuracy, and may raise those exceptions if the result is merely tiny. |
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