Avoid allocations due to usage of broadcasting operation (#1656)

* Avoid allocations due to usage of broadcasting operation * Comments & correcting copy-paste error --------- Co-authored-by: Hendrik Ranocha <[email protected]>
trixi-framework · Oct 5, 2023 · 67ddfbb · 67ddfbb
1 parent adce486
commit 67ddfbb
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/src/solvers/dgmulti/dg.jl b/src/solvers/dgmulti/dg.jl
@@ -302,7 +302,12 @@ function calc_volume_integral!(du, u, mesh::DGMultiMesh,
     @threaded for e in eachelement(mesh, dg, cache)
         flux_values = local_values_threaded[Threads.threadid()]
         for i in eachdim(mesh)
-            flux_values .= flux.(view(u_values, :, e), i, equations)
+            # Here, the broadcasting operation does allocate
+            #flux_values .= flux.(view(u_values, :, e), i, equations)
+            # Use loop instead
+            for j in eachindex(flux_values)
+                flux_values[j] = flux(u_values[j, e], i, equations)
+            end
             for j in eachdim(mesh)
                 apply_to_each_field(mul_by_accum!(weak_differentiation_matrices[j],
                                                   dxidxhatj[i, j][1, e]),
@@ -327,6 +332,7 @@ function calc_volume_integral!(du, u, mesh::DGMultiMesh{NDIMS, <:NonAffine},
     @threaded for e in eachelement(mesh, dg, cache)
         flux_values = cache.flux_threaded[Threads.threadid()]
         for i in eachdim(mesh)
+            # Here, the broadcasting operation does not allocate
             flux_values[i] .= flux.(view(u_values, :, e), i, equations)
         end