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Added RNG unit test.

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This commit is contained in:
Branimir Karadžić
2017-10-29 09:26:15 -07:00
parent 58c8c68062
commit bf39e556b0
3 changed files with 88 additions and 37 deletions
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19
include/bx/inline/rng.inl
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@@ -28,25 +28,6 @@ namespace bx
return (m_z<<16)+m_w;
}
inline RngFib::RngFib(uint32_t _a, uint32_t _b)
: m_a(_a)
, m_b(_b)
{
}
inline void RngFib::reset(uint32_t _a, uint32_t _b)
{
m_a = _a;
m_b = _b;
}
inline uint32_t RngFib::gen()
{
m_b = m_a+m_b;
m_a = m_b-m_a;
return m_a;
}
inline RngShr3::RngShr3(uint32_t _jsr)
: m_jsr(_jsr)
{

18
include/bx/rng.h
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@@ -30,24 +30,6 @@ namespace bx
uint32_t m_w;
};
/// George Marsaglia's FIB
class RngFib
{
public:
///
RngFib(uint32_t _a = 9983651, uint32_t _b = 95746118);
///
void reset(uint32_t _a = 9983651, uint32_t _b = 95746118);
///
uint32_t gen();
private:
uint32_t m_a;
uint32_t m_b;
};
/// George Marsaglia's SHR3
class RngShr3
{

88
tests/rng_test.cpp Normal file
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@@ -0,0 +1,88 @@
/*
* Copyright 2010-2017 Branimir Karadzic. All rights reserved.
* License: https://github.com/bkaradzic/bx#license-bsd-2-clause
*/
#include "test.h"
#include <bx/rng.h>
#include <bx/file.h>
const uint32_t kMax = 10<<20;
template<typename Ty>
void testRng(const char* _name, Ty* _rng)
{
uint32_t histBits[32];
uint32_t histUint8[256];
bx::memSet(histBits, 0, sizeof(histBits) );
bx::memSet(histUint8, 0, sizeof(histUint8) );
for (uint32_t ii = 0; ii < kMax; ++ii)
{
uint32_t val = _rng->gen();
for (uint32_t shift = 0; shift < 32; ++shift)
{
const uint32_t mask = 1<<shift;
histBits[shift] += !!(0 != (val & mask) );
}
const uint32_t mf000 = (val & 0xff000000)>>24;
const uint32_t m0f00 = (val & 0x00ff0000)>>16;
const uint32_t m00f0 = (val & 0x0000ff00)>> 8;
const uint32_t m000f = (val & 0x000000ff)>> 0;
histUint8[mf000]++;
histUint8[m0f00]++;
histUint8[m00f0]++;
histUint8[m000f]++;
}
bx::WriterI* writer = bx::getNullOut();
bx::writePrintf(writer, "%s\n", _name);
{
bx::writePrintf(writer, "\tbits histogram:\n");
uint32_t min = UINT32_MAX;
uint32_t max = 0;
for (uint32_t ii = 0; ii < BX_COUNTOF(histBits); ++ii)
{
bx::writePrintf(writer, "\t\t%3d: %d\n", ii, histBits[ii]);
min = bx::min(min, histBits[ii]);
max = bx::max(max, histBits[ii]);
}
bx::writePrintf(writer, "\tmin: %d, max: %d (diff: %d)\n", min, max, max-min);
REQUIRE(max-min < 8000);
}
{
bx::writePrintf(writer, "\tuint8_t histogram:\n");
uint32_t min = UINT32_MAX;
uint32_t max = 0;
for (uint32_t ii = 0; ii < BX_COUNTOF(histUint8); ++ii)
{
bx::writePrintf(writer, "\t\t%3d: %d\n", ii, histUint8[ii]);
min = bx::min(min, histUint8[ii]);
max = bx::max(max, histUint8[ii]);
}
bx::writePrintf(writer, "\tmin: %d, max: %d (diff: %d)\n", min, max, max-min);
REQUIRE(max-min < 8000);
}
}
TEST_CASE("Rng", "")
{
bx::RngMwc mwc;
testRng("RngMwc", &mwc);
bx::RngShr3 shr3;
testRng("RngShr3", &shr3);
}