Generate primitive velocity momenta BC for C++ target

1 files changed, 36 insertions, 0 deletions

diff --git a/boltzgen/kernel/template/basic.cpp.mako b/boltzgen/kernel/template/basic.cpp.mako
index 3e16d2e..468a292 100644
--- a/boltzgen/kernel/template/basic.cpp.mako
+++ b/boltzgen/kernel/template/basic.cpp.mako
@@ -43,6 +43,42 @@ void collide_and_stream(      ${float_type}* f_next,
 % endfor
 }
 
+void velocity_momenta_boundary(      ${float_type}* f_next,
+                               const ${float_type}* f_prev,
+                               std::size_t gid,
+                               ${float_type} velocity[${descriptor.d}])
+{
+          ${float_type}* preshifted_f_next = f_next + gid*${layout.gid_offset()};
+    const ${float_type}* preshifted_f_prev = f_prev + gid*${layout.gid_offset()};
+
+% for i, c_i in enumerate(descriptor.c):
+    const ${float_type} f_curr_${i} = preshifted_f_prev[${layout.pop_offset(i) + layout.neighbor_offset(-c_i)}];
+% endfor
+
+% for i, expr in enumerate(moments_subexpr):
+    const ${float_type} ${expr[0]} = ${ccode(expr[1])};
+% endfor
+
+% for i, expr in enumerate(moments_assignment):
+    ${float_type} ${ccode(expr)}
+% endfor
+% for i, expr in enumerate(moments_assignment[1:]):
+    ${expr.lhs} = velocity[${i}];
+% endfor
+
+% for i, expr in enumerate(collision_subexpr):
+    const ${float_type} ${expr[0]} = ${ccode(expr[1])};
+% endfor
+
+% for i, expr in enumerate(collision_assignment):
+    const ${float_type} ${ccode(expr)}
+% endfor
+
+% for i, expr in enumerate(collision_assignment):
+    preshifted_f_next[${layout.pop_offset(i)}] = f_next_${i};
+% endfor
+}
+
 void collect_moments(const ${float_type}* f,
                      std::size_t gid,
                      ${float_type}& rho,