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Added SIMD version of BitArray find. (#464)

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This commit is contained in:
Branimir Karadžić
2026-10-17 09:37:35 -07:00
committed by GitHub
parent ad000aeb31
commit fbadfc3abc
6 changed files with 1426 additions and 300 deletions
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59
tests/math_test.cpp
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@@ -205,6 +205,65 @@ TEST_CASE("countTrailingZeros", "[math]")
STATIC_REQUIRE(64 == bx::countTrailingZeros<uint64_t>(0) );
}
template<typename Ty>
static uint8_t countLeadingZerosRef(Ty _val)
{
uint8_t count = 0;
for (int32_t ii = sizeof(Ty)*8 - 1; ii >= 0 && 0 == ( (_val >> ii) & 1); --ii)
{
++count;
}
return count;
}
template<typename Ty>
static uint8_t countTrailingZerosRef(Ty _val)
{
uint8_t count = 0;
for (uint32_t ii = 0; ii < sizeof(Ty)*8 && 0 == ( (_val >> ii) & 1); ++ii)
{
++count;
}
return count;
}
template<typename Ty>
static void testCountZeros(Ty _val)
{
volatile Ty val = _val;
REQUIRE(countLeadingZerosRef<Ty>(_val) == bx::countLeadingZeros<Ty>(val) );
REQUIRE(countTrailingZerosRef<Ty>(_val) == bx::countTrailingZeros<Ty>(val) );
}
TEST_CASE("countLeadingZeros/countTrailingZeros runtime", "[math]")
{
testCountZeros<uint32_t>(0);
testCountZeros<uint64_t>(0);
for (uint32_t ii = 0; ii < 64; ++ii)
{
testCountZeros<uint32_t>(uint32_t(1) << (ii & 31) );
testCountZeros<uint64_t>(uint64_t(1) << ii);
testCountZeros<uint64_t>(UINT64_MAX << ii);
testCountZeros<uint64_t>(UINT64_MAX >> ii);
}
bx::RngMwc rng;
for (uint32_t ii = 0; ii < 10000; ++ii)
{
const uint64_t val = (uint64_t(rng.gen() ) << 32) | rng.gen();
const uint32_t shift = rng.gen() % 64;
testCountZeros<uint32_t>(uint32_t(val) >> (shift & 31) );
testCountZeros<uint64_t>(val >> shift);
testCountZeros<uint64_t>(val << shift);
}
}
TEST_CASE("countLeadingZeros", "[math]")
{
STATIC_REQUIRE( 7 == bx::countLeadingZeros<uint8_t >(1) );