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   6 .TH vpow_ 3MVEC "16 Jan 2009" "SunOS 5.11" "Vector Math Library Functions"
   7 .SH NAME
   8 vpow_, vpowf_ \- vector power functions
   9 .SH SYNOPSIS
  10 .LP
  11 .nf
  12 cc [ \fIflag\fR\&.\|.\|. ] \fIfile\fR\&.\|.\|. \fB-lmvec\fR [ \fIlibrary\fR\&.\|.\|. ]
  13 
  14 \fBvoid\fR \fBvpow_\fR(\fBint *\fR\fIn\fR, \fBdouble * restrict\fR \fIx\fR, \fBint *\fR\fIstridex\fR,
  15      \fBdouble * restrict\fR \fIy\fR, \fBint *\fR\fIstridey\fR, \fBdouble * restrict\fR \fIz\fR,
  16      \fBint *\fR\fIstridez\fR);
  17 .fi
  18 
  19 .LP
  20 .nf
  21 \fBvoid\fR \fBvpowf_\fR(\fBint *\fR\fIn\fR, \fBfloat * restrict\fR \fIx\fR, \fBint *\fR\fIstridex\fR,
  22      \fBfloat * restrict\fR \fIy\fR, \fBint *\fR\fIstridey\fR, \fBfloat * restrict\fR \fIz\fR,
  23      \fBint *\fR\fIstridez\fR);
  24 .fi
  25 
  26 .SH DESCRIPTION
  27 .sp
  28 .LP
  29 These functions evaluate the function \fBpow\fR(\fIx\fR, \fIy\fR) for an entire
  30 vector of values at once. The first parameter specifies the number of values to
  31 compute. Subsequent parameters specify the argument and result vectors. Each
  32 vector is described by a pointer to the first element and a stride, which is
  33 the increment between successive elements.
  34 .sp
  35 .LP
  36 Specifically, \fBvpow_\fR(\fIn\fR, \fIx\fR, \fIsx\fR, \fIy\fR, \fIsy\fR,
  37 \fIz\fR, \fIsz\fR) computes \fIz\fR[\fIi\fR * *\fIsz\fR] =
  38 \fBpow\fR(\fIx\fR[\fIi\fR * *\fIsx\fR], \fIy\fR[\fIi\fR * *\fIsy\fR]) for each
  39 \fIi\fR = 0, 1, ..., *\fIn\fR - 1. The \fBvpowf_()\fR function performs the
  40 same computation for single precision data.
  41 .sp
  42 .LP
  43 These functions are not guaranteed to deliver results that are identical to the
  44 results of the \fBpow\fR(3M) functions given the same arguments.
  45 Non-exceptional results, however, are accurate to within a unit in the last
  46 place.
  47 .SH USAGE
  48 .sp
  49 .LP
  50 The element count *\fIn\fR must be greater than zero. The strides for the
  51 argument and result arrays can be arbitrary integers, but the arrays themselves
  52 must not be the same or overlap. A zero stride effectively collapses an entire
  53 vector into a single element. A negative stride causes a vector to be accessed
  54 in descending memory order, but note that the corresponding pointer must still
  55 point to the first element of the vector to be used; if the stride is negative,
  56 this will be the highest-addressed element in memory. This convention differs
  57 from the Level 1 BLAS, in which array parameters always refer to the
  58 lowest-addressed element in memory even when negative increments are used.
  59 .sp
  60 .LP
  61 These functions assume that the default round-to-nearest rounding direction
  62 mode is in effect. On x86, these functions also assume that the default
  63 round-to-64-bit rounding precision mode is in effect. The result of calling a
  64 vector function with a non-default rounding mode in effect is undefined.
  65 .sp
  66 .LP
  67 The results of these functions for special cases and exceptions match that of
  68 the \fBpow()\fR functions when the latter are used in a program compiled with
  69 the \fBcc\fR compiler driver (that is, not SUSv3-conforming) and the expression
  70 (\fBmath_errhandling\fR & \fBMATH_ERREXCEPT\fR) is non-zero. These functions do
  71 not set \fBerrno\fR. See \fBpow\fR(3M) for the results for special cases.
  72 .sp
  73 .LP
  74 An application wanting to check for exceptions should call
  75 \fBfeclearexcept\fR(\fBFE_ALL_EXCEPT\fR) before calling these functions. On
  76 return, if \fBfetestexcept\fR(\fBFE_INVALID\fR | \fBFE_DIVBYZERO\fR |
  77 \fBFE_OVERFLOW\fR | \fBFE_UNDERFLOW\fR) is non-zero, an exception has been
  78 raised. The application can then examine the result or argument vectors for
  79 exceptional values. Some vector functions can raise the inexact exception even
  80 if all elements of the argument array are such that the numerical results are
  81 exact.
  82 .SH ATTRIBUTES
  83 .sp
  84 .LP
  85 See \fBattributes\fR(5) for descriptions of the following attributes:
  86 .sp
  87 
  88 .sp
  89 .TS
  90 tab() box;
  91 cw(2.75i) |cw(2.75i) 
  92 lw(2.75i) |lw(2.75i) 
  93 .
  94 ATTRIBUTE TYPEATTRIBUTE VALUE
  95 _
  96 Interface StabilityCommitted
  97 _
  98 MT-LevelMT-Safe
  99 .TE
 100 
 101 .SH SEE ALSO
 102 .sp
 103 .LP
 104 \fBpow\fR(3M), \fBfeclearexcept\fR(3M), \fBfetestexcept\fR(3M),
 105 \fBattributes\fR(5)