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6 .TH VSQRT_ 3MVEC "Dec 14, 2007" "SunOS 5.11" "Vector Math Library Functions"
8 vsqrt_, vsqrtf_ \- vector square root functions
12 cc [ \fIflag\fR\&.\|.\|. ] \fIfile\fR\&.\|.\|. \fB-lmvec\fR [ \fIlibrary\fR\&.\|.\|. ]
14 \fBvoid\fR \fBvsqrt_\fR(\fBint *\fR\fIn\fR, \fBdouble * restrict\fR \fIx\fR, \fBint *\fR\fIstridex\fR,
15 \fBdouble * restrict\fR \fIy\fR, \fBint *\fR\fIstridey\fR);
20 \fBvoid\fR \fBvsqrtf_\fR(\fBint *\fR\fIn\fR, \fBfloat * restrict\fR \fIx\fR, \fBint *\fR\fIstridex\fR,
21 \fBfloat * restrict\fR \fIy\fR, \fBint *\fR\fIstridey\fR);
27 These functions evaluate the function \fBsqrt\fR(\fIx\fR) for an entire vector
28 of values at once. The first parameter specifies the number of values to
29 compute. Subsequent parameters specify the argument and result vectors. Each
30 vector is described by a pointer to the first element and a stride, which is
31 the increment between successive elements.
34 Specifically, \fBvsqrt_\fR(\fIn\fR, \fIx\fR, \fIsx\fR, \fIy\fR, \fIsy\fR)
35 computes \fIy\fR[\fIi\fR * *\fIsy\fR] = \fBsqrt\fR(\fIx\fR[\fIi\fR *
36 *\fIsx\fR]) for each \fIi\fR = 0, 1, ..., *\fIn\fR - 1. The \fBvsqrtf_()\fR
37 function performs the same computation for single precision data.
40 Unlike their scalar counterparts, these functions do not always deliver
41 correctly rounded results. However, the error in each non-exceptional result is
42 less than one unit in the last place.
46 The element count *\fIn\fR must be greater than zero. The strides for the
47 argument and result arrays can be arbitrary integers, but the arrays themselves
48 must not be the same or overlap. A zero stride effectively collapses an entire
49 vector into a single element. A negative stride causes a vector to be accessed
50 in descending memory order, but note that the corresponding pointer must still
51 point to the first element of the vector to be used; if the stride is negative,
52 this will be the highest-addressed element in memory. This convention differs
53 from the Level 1 BLAS, in which array parameters always refer to the
54 lowest-addressed element in memory even when negative increments are used.
57 These functions assume that the default round-to-nearest rounding direction
58 mode is in effect. On x86, these functions also assume that the default
59 round-to-64-bit rounding precision mode is in effect. The result of calling a
60 vector function with a non-default rounding mode in effect is undefined.
63 These functions handle special cases and exceptions in the same way as the
64 \fBsqrt()\fR functions when \fBc99\fR \fBMATHERREXCEPT\fR conventions are in
65 effect. See \fBsqrt\fR(3M) for the results for special cases.
68 An application wanting to check for exceptions should call
69 \fBfeclearexcept\fR(\fBFE_ALL_EXCEPT\fR) before calling these functions. On
70 return, if \fBfetestexcept\fR(\fBFE_INVALID\fR | \fBFE_DIVBYZERO\fR |
71 \fBFE_OVERFLOW\fR | \fBFE_UNDERFLOW\fR) is non-zero, an exception has been
72 raised. The application can then examine the result or argument vectors for
73 exceptional values. Some vector functions can raise the inexact exception even
74 if all elements of the argument array are such that the numerical results are
79 See \fBattributes\fR(5) for descriptions of the following attributes:
88 ATTRIBUTE TYPE ATTRIBUTE VALUE
90 Interface Stability Committed
98 \fBsqrt\fR(3M), \fBfeclearexcept\fR(3M), \fBfetestexcept\fR(3M),