opensolaris man page for vpowf_

vpow_(3MVEC)						   Vector Math Library Functions					      vpow_(3MVEC)

NAME
       vpow_, vpowf_ - vector power functions

SYNOPSIS
       cc [ flag... ] file... -lmvec [ library... ]

       void vpow_(int *n, double * restrict x, int *stridex,
	    double * restrict y, int *stridey, double * restrict z,
	    int *stridez);

       void vpowf_(int *n, float * restrict x, int *stridex,
	    float * restrict y, int *stridey, float * restrict z,
	    int *stridez);

DESCRIPTION
       These  functions evaluate the function pow(x, y) for an entire vector of values at once. The first parameter specifies the number of values
       to compute. Subsequent parameters specify the argument and result vectors. Each vector is described by a pointer to the first element and a
       stride, which is the increment between successive elements.

       Specifically,  vpow_(n, x, sx, y, sy, z, sz) computes z[i * *sz] = pow(x[i * *sx], y[i * *sy]) for each i = 0, 1, ..., *n - 1. The vpowf_()
       function performs the same computation for single precision data.

       These functions are not guaranteed to deliver results that are identical to the results of the pow(3M) functions given the same	arguments.
       Non-exceptional results, however, are accurate to within a unit in the last place.

USAGE
       The  element  count  *n must be greater than zero. The strides for the argument and result arrays can be arbitrary integers, but the arrays
       themselves must not be the same or overlap. A zero stride effectively collapses an entire vector into a single element. A  negative  stride
       causes a vector to be accessed in descending memory order, but note that the corresponding pointer must still point to the first element of
       the vector to be used; if the stride is negative, this will be the highest-addressed element in memory. This convention	differs  from  the
       Level 1 BLAS, in which array parameters always refer to the lowest-addressed element in memory even when negative increments are used.

       These functions assume that the default round-to-nearest rounding direction mode is in effect. On x86, these functions also assume that the
       default round-to-64-bit rounding precision mode is in effect. The result of calling a vector function with a non-default rounding  mode	in
       effect is undefined.

       The  results  of  these	functions for special cases and exceptions match that of the pow() functions when the latter are used in a program
       compiled with the cc compiler driver (that is, not SUSv3-conforming) and the expression (math_errhandling &  MATH_ERREXCEPT)  is  non-zero.
       These functions do not set errno. See pow(3M) for the results for special cases.

       An  application	wanting  to  check  for  exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if
       fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. The  application  can  then
       examine	the  result or argument vectors for exceptional values. Some vector functions can raise the inexact exception even if all elements
       of the argument array are such that the numerical results are exact.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed 		   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       pow(3M), feclearexcept(3M), fetestexcept(3M), attributes(5)

SunOS 5.11							    16 Jan 2009 						      vpow_(3MVEC)