Codegen C - Structured SwitchValue partial support, unify Switch handling

3 files changed, 66 insertions, 34 deletions

diff --git a/src/trans/codegen_c.cpp b/src/trans/codegen_c.cpp
index c42b4b1f..4b0f0fc6 100644
--- a/src/trans/codegen_c.cpp
+++ b/src/trans/codegen_c.cpp
@@ -2058,38 +2058,9 @@ namespace {
                     m_of << "\tif("; emit_lvalue(e.cond); m_of << ") goto bb" << e.bb0 << "; else goto bb" << e.bb1 << ";\n";
                     ),
                 (Switch,
-                    ::HIR::TypeRef  tmp;
-                    const auto& ty = mir_res.get_lvalue_type(tmp, e.val);
-                    MIR_ASSERT(mir_res, ty.m_data.is_Path(), "Switch of a non-enum - " << ty);
-                    MIR_ASSERT(mir_res, ty.m_data.as_Path().binding.is_Enum(), "Switch of a non-enum - " << ty);
-                    const auto* enm = ty.m_data.as_Path().binding.as_Enum();
-                    auto it = m_enum_repr_cache.find( ty.m_data.as_Path().path.m_data.as_Generic() );
-                    if( it != m_enum_repr_cache.end() )
-                    {
-                        MIR_ASSERT(mir_res, e.targets.size() == 2, "Non-zero optimised type a variant count that isn't 2");
-                        m_of << "\tif("; emit_lvalue(e.val); m_of << "._1"; emit_nonzero_path(it->second); m_of << ")\n";
-                        m_of << "\t\tgoto bb" << e.targets[1] << ";\n";
-                        m_of << "\telse\n";
-                        m_of << "\t\tgoto bb" << e.targets[0] << ";\n";
-                    }
-                    else if( enm->is_value() )
-                    {
-                        m_of << "\tswitch("; emit_lvalue(e.val); m_of << ".TAG) {\n";
-                        for(unsigned int j = 0; j < e.targets.size(); j ++)
-                        {
-                            m_of << "\t\tcase " << enm->get_value(j) << ": goto bb" << e.targets[j] << ";\n";
-                        }
-                        m_of << "\t\tdefault: abort();\n";
-                        m_of << "\t}\n";
-                    }
-                    else
-                    {
-                        m_of << "\tswitch("; emit_lvalue(e.val); m_of << ".TAG) {\n";
-                        for(unsigned int j = 0; j < e.targets.size(); j ++)
-                            m_of << "\t\tcase " << j << ": goto bb" << e.targets[j] << ";\n";
-                        m_of << "\t\tdefault: abort();\n";
-                        m_of << "\t}\n";
-                    }
+                    emit_term_switch(mir_res, e.val, e.targets.size(), 1, [&](size_t idx) {
+                        m_of << "goto bb" << e.targets[idx] << ";";
+                        });
                     ),
                 (SwitchValue,
                     ::HIR::TypeRef  tmp;
@@ -2203,7 +2174,6 @@ namespace {
                             //assert(i == e.nodes.size()-1 && "If");
                             ),
                         (Call,
-                            // TODO: Emit call
                             emit_term_call(mir_res, te, indent_level);
                             ),
                         (Switch,
@@ -2253,6 +2223,9 @@ namespace {
                     }
                     });
                 ),
+            (SwitchValue,
+                MIR_TODO(mir_res, "SwitchValue");
+                ),
             (Loop,
                 m_of << indent << "for(;;) {\n";
                 assert(e.code.node);
diff --git a/src/trans/codegen_c.hpp b/src/trans/codegen_c.hpp
index 72d0c796..5c9afe12 100644
--- a/src/trans/codegen_c.hpp
+++ b/src/trans/codegen_c.hpp
@@ -38,6 +38,13 @@ TAGGED_UNION(Node, Block,
     const ::MIR::LValue* val;
     ::std::vector<NodeRef>  arms;
     }),
+(SwitchValue, struct {
+    size_t  next_bb;
+    const ::MIR::LValue* val;
+    NodeRef def_arm;
+    ::std::vector<NodeRef>  arms;
+    const ::MIR::SwitchValues*  vals;
+    }),
 (Loop, struct {
     size_t  next_bb;
     NodeRef code;
diff --git a/src/trans/codegen_c_structured.cpp b/src/trans/codegen_c_structured.cpp
index 888f9a26..f35de9f8 100644
--- a/src/trans/codegen_c_structured.cpp
+++ b/src/trans/codegen_c_structured.cpp
@@ -28,6 +28,9 @@ bool NodeRef::has_target() const
         (Switch,
             return e.next_bb != SIZE_MAX;
             ),
+        (SwitchValue,
+            return e.next_bb != SIZE_MAX;
+            ),
         (Loop,
             return e.next_bb != SIZE_MAX;
             )
@@ -51,6 +54,9 @@ size_t NodeRef::target() const
         (Switch,
             return e.next_bb;
             ),
+        (SwitchValue,
+            return e.next_bb;
+            ),
         (Loop,
             return e.next_bb;
             )
@@ -164,6 +170,7 @@ public:
                         next_blocks.push_back( arms.back().target() );
                     }
                 }
+                // TODO: Make the next block common
                 ::std::sort(next_blocks.begin(), next_blocks.end());
                 size_t  exit_bb = SIZE_MAX;
                 if(!next_blocks.empty())
@@ -189,10 +196,55 @@ public:
                     }
                 }
                 refs.push_back(Node::make_Switch({ exit_bb, &te.val, mv$(arms) }));
+                // TODO: Continue with the exit bb?
                 stop = true;
                 ),
             (SwitchValue,
-                TODO(Span(), "SwitchValue");
+                ::std::vector<NodeRef>  arms;
+                ::std::vector<size_t>   next_blocks;
+                for(auto& tgt : te.targets)
+                {
+                    arms.push_back( process_node_ref(tgt) );
+                    if( arms.back().has_target() )
+                    {
+                        next_blocks.push_back( arms.back().target() );
+                    }
+                }
+                auto def_arm = process_node_ref(te.def_target);
+                if(def_arm.has_target())
+                {
+                    next_blocks.push_back(def_arm.target());
+                }
+
+                // TODO: Make the next block common
+                ::std::sort(next_blocks.begin(), next_blocks.end());
+                size_t  exit_bb = SIZE_MAX;
+                if(!next_blocks.empty())
+                {
+                    size_t  cur = next_blocks[0];
+                    size_t  cur_count = 0;
+                    size_t  max_count = 0;
+                    for(auto b : next_blocks)
+                    {
+                        if(cur == b) {
+                            cur_count ++;
+                        }
+                        else {
+                            if( cur_count > max_count ) {
+                                exit_bb = cur;
+                            }
+                            cur = b;
+                            cur_count = 1;
+                        }
+                    }
+                    if( cur_count > max_count ) {
+                        exit_bb = cur;
+                    }
+                }
+
+                refs.push_back(Node::make_SwitchValue({ exit_bb, &te.val, mv$(def_arm), mv$(arms), &te.values }));
+                stop = true;
+
                 ),
             (Call,
                 // NOTE: Let the panic arm just be a goto