update the type name and add more assert to check foci

Co-authored-by: Marcel Koch <marcel.koch@kit.edu>

Author: yhmtsai

common/unified/solver/chebyshev_kernels.cpp

@@ -47,13 +47,13 @@ void init_update(std::shared_ptr<const DefaultExecutor> exec,
                  matrix::Dense<ValueType>* update_sol,
                  matrix::Dense<ValueType>* output)
 {
-    using backend_coeff_type =
+    using coeff_type =
         if_single_only_type<solver::detail::coeff_type<ValueType>>;
-    // the backend_coeff_type always be the highest precision, so we need
+    // the coeff_type always be the highest precision, so we need
     // to cast the others from ValueType to this precision.
-    using arithmetic_type = device_type<backend_coeff_type>;
+    using arithmetic_type = device_type<coeff_type>;
 
-    auto alpha_val = static_cast<backend_coeff_type>(alpha);
+    auto alpha_val = static_cast<coeff_type>(alpha);
 
     run_kernel(
         exec,
@@ -81,14 +81,14 @@ void update(std::shared_ptr<const DefaultExecutor> exec,
             matrix::Dense<ValueType>* update_sol,
             matrix::Dense<ValueType>* output)
 {
-    using backend_coeff_type =
+    using coeff_type =
         if_single_only_type<solver::detail::coeff_type<ValueType>>;
-    // the backend_coeff_type always be the highest precision, so we need
+    // the coeff_type always be the highest precision, so we need
     // to cast the others from ValueType to this precision.
-    using arithmetic_type = device_type<backend_coeff_type>;
+    using arithmetic_type = device_type<coeff_type>;
 
-    auto alpha_val = static_cast<backend_coeff_type>(alpha);
-    auto beta_val = static_cast<backend_coeff_type>(beta);
+    auto alpha_val = static_cast<coeff_type>(alpha);
+    auto beta_val = static_cast<coeff_type>(beta);
 
     run_kernel(
         exec,

core/solver/chebyshev.cpp

@@ -85,10 +85,13 @@ Chebyshev<ValueType>::Chebyshev(const Factory* factory,
     auto left_foci = std::get<0>(parameters_.foci);
     auto right_foci = std::get<1>(parameters_.foci);
     GKO_ASSERT(real(left_foci) <= real(right_foci));
+    GKO_ASSERT(is_nonzero(left_foci) || is_nonzero(right_foci));
     center_ =
         (left_foci + right_foci) / solver::detail::coeff_type<ValueType>{2};
     foci_direction_ =
         (right_foci - left_foci) / solver::detail::coeff_type<ValueType>{2};
+    // if the center is zero then the alpha will be inf
+    GKO_ASSERT(is_nonzero(center_));
 }
 
 

reference/solver/chebyshev_kernels.cpp

@@ -20,7 +20,7 @@ void init_update(std::shared_ptr<const DefaultExecutor> exec,
                  matrix::Dense<ValueType>* update_sol,
                  matrix::Dense<ValueType>* output)
 {
-    // the backend_coeff_type always be the highest precision, so we need
+    // the coeff_type always be the highest precision, so we need
     // to cast the others from ValueType to this precision.
     using arithmetic_type = solver::detail::coeff_type<ValueType>;
     for (size_t row = 0; row < output->get_size()[0]; row++) {
@@ -46,7 +46,7 @@ void update(std::shared_ptr<const DefaultExecutor> exec,
             matrix::Dense<ValueType>* update_sol,
             matrix::Dense<ValueType>* output)
 {
-    // the backend_coeff_type always be the highest precision, so we need
+    // the coeff_type always be the highest precision, so we need
     // to cast the others from ValueType to this precision.
     using arithmetic_type = solver::detail::coeff_type<ValueType>;
     for (size_t row = 0; row < output->get_size()[0]; row++) {