Developer Reference

  • 0.9
  • 09/09/2020
  • Public Content
Contents

vRngUniformBits

Generates
bits of underlying BRNG integer recurrence.

Syntax

status
=
viRngUniformBits
(
method
,
stream
,
n
,
r
);
Include Files
  • mkl.h
Input Parameters
Name
Type
Description
method
const MKL_INT
Generation method; the specific value is
VSL_RNG_METHOD_UNIFORMBITS_STD
stream
VSLStreamStatePtr
Pointer to the stream state structure
n
const MKL_INT
Number of random values to be generated
Output Parameters
Name
Type
Description
r
unsigned int*
Vector of
n
random integer numbers. If the
stream
was generated by a 64 or a 128-bit generator, each integer value is represented by two or four elements of
r
respectively. The number of bytes occupied by each integer is contained in the field
WordSize
of the structure
VSLBRngProperties
. The total number of bits that are actually used to store the value are contained in the field
NBits
of the same structure.
See Advanced Service Routines for a more detailed discussion of
VSLBRngProperties
.
Description
The
vRngUniformBits
function generates integer random values with uniform bit distribution. The generators of uniformly distributed numbers can be represented as recurrence relations over integer values in modular arithmetic. Apparently, each integer can be treated as a vector of several bits. In a truly random generator, these bits are random, while in pseudorandom generators this randomness can be violated. For example, a well known drawback of linear congruential generators is that lower bits are less random than higher bits (for example, see [Knuth81]). For this reason, care should be taken when using this function. Typically, in a 32-bit
LCG
only 24 higher bits of an integer value can be considered random. See VS Notes for details.
Optimization Notice
Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.
Notice revision #20110804
This notice covers the following instruction sets: SSE2, SSE4.2, AVX2, AVX-512.
Return Values
VSL_ERROR_OK, VSL_STATUS_OK
Indicates no error, execution is successful.
VSL_ERROR_NULL_PTR
stream
is a
NULL
pointer.
VSL_RNG_ERROR_BAD_STREAM
stream
is not a valid random stream.
VSL_RNG_ERROR_BAD_UPDATE
Callback function for an abstract BRNG returns an invalid number of updated entries in a buffer, that is,
< 0
or
>
nmax
.
VSL_RNG_ERROR_NO_NUMBERS
Callback function for an abstract BRNG returns 0 as the number of updated entries in a buffer.
VSL_RNG_ERROR_QRNG_PERIOD_ELAPSED
Period of the generator has been exceeded.
VSL_RNG_ERROR_NONDETERM_NRETRIES_EXCEEDED
Number of retries to generate a random number by using non-deterministic random number generator exceeds threshold.
VSL_RNG_ERROR_ARS5_NOT_SUPPORTED
ARS-5 random number generator is not supported on the CPU running the application.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804