compiler: create var in `shortcut_equate` only if needed

[nit.git] / src / compiler / separate_compiler.nit

diff --git a/src/compiler/separate_compiler.nit b/src/compiler/separate_compiler.nit
index 491ebfe..54c51b2 100644 (file)
--- a/src/compiler/separate_compiler.nit
+++ b/src/compiler/separate_compiler.nit
@@ -418,13 +418,12 @@ class SeparateCompiler
                var live_cast_types = runtime_type_analysis.live_cast_types
                var mtypes = new HashSet[MType]
                mtypes.add_all(live_types)
-               mtypes.add_all(live_cast_types)
                for c in self.box_kinds.keys do
                        mtypes.add(c.mclass_type)
                end
 
                # Compute colors
-               var poset = poset_from_mtypes(mtypes)
+               var poset = poset_from_mtypes(mtypes, live_cast_types)
                var colorer = new POSetColorer[MType]
                colorer.colorize(poset)
                type_ids = colorer.ids
@@ -437,12 +436,13 @@ class SeparateCompiler
                return poset
        end
 
-       private fun poset_from_mtypes(mtypes: Set[MType]): POSet[MType] do
+       private fun poset_from_mtypes(mtypes, cast_types: Set[MType]): POSet[MType] do
                var poset = new POSet[MType]
                for e in mtypes do
                        poset.add_node(e)
-                       for o in mtypes do
+                       for o in cast_types do
                                if e == o then continue
+                               poset.add_node(o)
                                if e.is_subtype(mainmodule, null, o) then
                                        poset.add_edge(e, o)
                                end
@@ -1143,10 +1143,10 @@ class SeparateCompilerVisitor
                        self.add("\{")
                end
                if not self.compiler.modelbuilder.toolcontext.opt_no_shortcut_equate.value and (mmethod.name == "==" or mmethod.name == "!=") then
-                       if res == null then res = self.new_var(bool_type)
-                       # Recv is not null, thus is arg is, it is easy to conclude (and respect the invariants)
+                       # Recv is not null, thus if arg is, it is easy to conclude (and respect the invariants)
                        var arg = arguments[1]
                        if arg.mcasttype isa MNullType then
+                               if res == null then res = self.new_var(bool_type)
                                if mmethod.name == "==" then
                                        self.add("{res} = 0; /* arg is null but recv is not */")
                                else