cuda: Add support for constexpr array compilation inputs

Author: zatkins-dev

backends/cuda/ceed-cuda-compile.cpp

@@ -21,6 +21,7 @@
 
 #include <cstdlib>
 #include <fstream>
+#include <iomanip>
 #include <iostream>
 #include <sstream>
 #include <string>
@@ -421,6 +422,29 @@ static int CeedCompileCore_Cuda(Ceed ceed, const char *source, const bool throw_
   return CEED_ERROR_SUCCESS;
 }
 
+template <typename ArrayT>
+struct CeedArrayView {
+  const ArrayT *array;
+  CeedInt       size;
+
+  CeedArrayView(const ArrayT *array_, CeedInt size_) : array(array_), size(size_) {}
+};
+
+template <typename OStream, typename ArrayT>
+OStream &operator<<(OStream &ostream, const CeedArrayView<ArrayT> &view) {
+  ostream << "{";
+  for (CeedInt i = 0; i < view.size; i++) ostream << std::setprecision(17) << view.array[i] << (i == view.size - 1 ? "}" : ", ");
+  return ostream;
+}
+
+int CeedBuildArrayConstantSize_Cuda(Ceed ceed, const char *name, CeedInt length, const CeedSize *array, char **line) {
+  std::ostringstream code;
+
+  code << "constexpr CeedSize " << name << "[" << length << "] = " << CeedArrayView<CeedSize>(array, length) << ";";
+  CeedCallBackend(CeedStringAllocCopy(code.str().c_str(), line));
+  return CEED_ERROR_SUCCESS;
+}
+
 int CeedCompile_Cuda(Ceed ceed, const char *source, CUmodule *module, const CeedInt num_defines, ...) {
   bool    is_compile_good = true;
   va_list args;

backends/cuda/ceed-cuda-compile.h

@@ -12,6 +12,8 @@
 
 static inline CeedInt CeedDivUpInt(CeedInt numerator, CeedInt denominator) { return (numerator + denominator - 1) / denominator; }
 
+CEED_INTERN int CeedBuildArrayConstantSize_Cuda(Ceed ceed, const char *name, CeedInt length, const CeedSize *array, char **line);
+
 CEED_INTERN int CeedCompile_Cuda(Ceed ceed, const char *source, CUmodule *module, const CeedInt num_defines, ...);
 CEED_INTERN int CeedTryCompile_Cuda(Ceed ceed, const char *source, bool *is_compile_good, CUmodule *module, const CeedInt num_defines, ...);