Date: 2026-07-30T21:14:23+00:00

Actual source code: curand2.cu

      1: #include <petsc/private/randomimpl.h>
      2: #include <thrust/transform.h>
      3: #include <thrust/device_ptr.h>
      4: #include <thrust/iterator/counting_iterator.h>

      6: #if defined(PETSC_USE_COMPLEX)
      7: struct complexscalelw
      8:   #if PETSC_PKG_CUDA_VERSION_LT(12, 8, 0)
      9:   :
     10:   public thrust::unary_function<thrust::tuple<PetscReal, size_t>, PetscReal>
     11:   #endif
     12: {
     13:   PetscReal rl, rw;
     14:   PetscReal il, iw;

     16:   complexscalelw(PetscScalar low, PetscScalar width)
     17:   {
     18:     rl = PetscRealPart(low);
     19:     il = PetscImaginaryPart(low);
     20:     rw = PetscRealPart(width);
     21:     iw = PetscImaginaryPart(width);
     22:   }

     24:   __host__ __device__ PetscReal operator()(thrust::tuple<PetscReal, size_t> x) { return thrust::get<1>(x) % 2 ? thrust::get<0>(x) * iw + il : thrust::get<0>(x) * rw + rl; }
     25: };
     26: #endif

     28: struct realscalelw
     29: #if PETSC_PKG_CUDA_VERSION_LT(12, 8, 0) // To suppress the warning "thrust::THRUST_200700_860_NS::unary_function is deprecated"
     30:   :
     31:   public thrust::unary_function<PetscReal, PetscReal>
     32: #endif
     33: {
     34:   PetscReal l, w;

     36:   realscalelw(PetscReal low, PetscReal width) : l(low), w(width) { }

     38:   __host__ __device__ PetscReal operator()(PetscReal x) { return x * w + l; }
     39: };

     41: PETSC_INTERN PetscErrorCode PetscRandomCurandScale_Private(PetscRandom r, size_t n, PetscReal *val, PetscBool isneg)
     42: {
     43:   PetscFunctionBegin;
     44:   if (!r->iset) PetscFunctionReturn(PETSC_SUCCESS);
     45:   if (isneg) { /* complex case, need to scale differently */
     46: #if defined(PETSC_USE_COMPLEX)
     47:     thrust::device_ptr<PetscReal> pval  = thrust::device_pointer_cast(val);
     48:     auto                          zibit = thrust::make_zip_iterator(thrust::make_tuple(pval, thrust::counting_iterator<size_t>(0)));
     49:     thrust::transform(zibit, zibit + n, pval, complexscalelw(r->low, r->width));
     50: #else
     51:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Negative array size %" PetscInt_FMT, (PetscInt)n);
     52: #endif
     53:   } else {
     54:     PetscReal                     rl   = PetscRealPart(r->low);
     55:     PetscReal                     rw   = PetscRealPart(r->width);
     56:     thrust::device_ptr<PetscReal> pval = thrust::device_pointer_cast(val);
     57:     thrust::transform(pval, pval + n, pval, realscalelw(rl, rw));
     58:   }
     59:   PetscFunctionReturn(PETSC_SUCCESS);
     60: }