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Incorrect machine constant checks for Legendre recursion relations #106

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Merged
The9Cat merged 1 commit into from
Feb 7, 2025
Merged

Incorrect machine constant checks for Legendre recursion relations #106

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2 changes: 1 addition & 1 deletion src/Basis.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@

// Machine constant for Legendre
//
constexpr double MINEPS = 20.0*std::numeric_limits<double>::min();
constexpr double MINEPS = 3.0*std::numeric_limits<double>::epsilon();

Basis::Basis(Component* c0, const YAML::Node& conf) : PotAccel(c0, conf)
{
Expand Down
20 changes: 15 additions & 5 deletions src/cudaSphericalBasis.cu
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@
// Global symbols for coordinate transformation in SphericalBasis
//
__device__ __constant__
cuFP_t sphScale, sphRscale, sphHscale, sphXmin, sphXmax, sphDxi, sphCen[3];
cuFP_t sphScale, sphRscale, sphHscale, sphXmin, sphXmax, sphDxi, sphCen[3], sphEPS;

__device__ __constant__
int sphNumr, sphCmap;
Expand Down Expand Up @@ -80,7 +80,7 @@ void legendre_v(int lmax, cuFP_t x, cuFP_t* p)
}


__host__ __device__
__device__
void legendre_v2(int lmax, cuFP_t x, cuFP_t* p, cuFP_t* dp)
{
cuFP_t fact, somx2, pll, pl1, pl2;
Expand All @@ -106,9 +106,9 @@ void legendre_v2(int lmax, cuFP_t x, cuFP_t* p, cuFP_t* dp)
}
}

if (1.0-fabs(x) < MINEPS) {
if (x>0) x = 1.0 - MINEPS;
else x = -(1.0 - MINEPS);
if (1.0-fabs(x) < sphEPS) {
if (x>0) x = 1.0 - sphEPS;
else x = -(1.0 - sphEPS);
}

somx2 = 1.0/(x*x - 1.0);
Expand All @@ -134,6 +134,7 @@ void testConstantsSph()
printf(" Dxi = %f\n", sphDxi );
printf(" Numr = %d\n", sphNumr );
printf(" Cmap = %d\n", sphCmap );
printf(" Feps = %d\n", sphEPS );
printf("-------------------------\n");
}

Expand Down Expand Up @@ -231,6 +232,15 @@ void SphericalBasis::initialize_mapping_constants()
__FILE__, __LINE__, "Error copying sphEVEN_M");
cuda_safe_call(cudaMemcpyToSymbol(sphM0only, &M0_only, sizeof(bool), size_t(0), cudaMemcpyHostToDevice),
__FILE__, __LINE__, "Error copying sphM0only");

#if cuREAL == 4
cuFP_t feps = 3.0*std::numeric_limits<float>::epsilon();
#else
cuFP_t feps = 3.0*std::numeric_limits<double>::epsilon();
#endif

cuda_safe_call(cudaMemcpyToSymbol(sphEPS, &feps, sizeof(cuFP_t), size_t(0), cudaMemcpyHostToDevice),
__FILE__, __LINE__, "Error copying sphEPS");
}


Expand Down