separate_compiler: `shortcut_equate` works on `is_same_instance`

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

diff --git a/src/compiler/separate_compiler.nit b/src/compiler/separate_compiler.nit
index 491ebfe..33e8d8a 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
@@ -1112,10 +1112,10 @@ class SeparateCompilerVisitor
                var res: nullable RuntimeVariable = null
                var recv = arguments.first
                var consider_null = not self.compiler.modelbuilder.toolcontext.opt_no_check_null.value or mmethod.name == "==" or mmethod.name == "!="
-               var maybenull = recv.mcasttype isa MNullableType and consider_null
+               var maybenull = (recv.mcasttype isa MNullableType or recv.mcasttype isa MNullType) and consider_null
                if maybenull then
                        self.add("if ({recv} == NULL) \{")
-                       if mmethod.name == "==" then
+                       if mmethod.name == "==" or mmethod.name == "is_same_instance" then
                                res = self.new_var(bool_type)
                                var arg = arguments[1]
                                if arg.mcasttype isa MNullableType then
@@ -1142,15 +1142,15 @@ class SeparateCompilerVisitor
                else
                        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)
+               if not self.compiler.modelbuilder.toolcontext.opt_no_shortcut_equate.value and (mmethod.name == "==" or mmethod.name == "!=" or mmethod.name == "is_same_instance") then
+                       # 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 mmethod.name == "==" then
-                                       self.add("{res} = 0; /* arg is null but recv is not */")
-                               else
+                               if res == null then res = self.new_var(bool_type)
+                               if mmethod.name == "!=" then
                                        self.add("{res} = 1; /* arg is null and recv is not */")
+                               else # `==` and `is_same_instance`
+                                       self.add("{res} = 0; /* arg is null but recv is not */")
                                end
                                self.add("\}") # closes the null case
                                self.add("if (0) \{") # what follow is useless, CC will drop it