nitgs: opt_direct_call_monomorph call `before_send` to deal with special cases
[nit.git] / src / separate_compiler.nit
index 62dc582..96978f0 100644 (file)
@@ -1012,13 +1012,21 @@ class SeparateCompilerVisitor
        do
                var rta = compiler.runtime_type_analysis
                var recv = args.first.mtype
-               if compiler.modelbuilder.toolcontext.opt_direct_call_monomorph.value and rta != null and recv isa MClassType then
+               if compiler.modelbuilder.toolcontext.opt_direct_call_monomorph.value and rta != null then
                        var tgs = rta.live_targets(callsite)
                        if tgs.length == 1 then
                                # DIRECT CALL
                                var mmethod = callsite.mproperty
                                self.varargize(mmethod.intro, mmethod.intro.msignature.as(not null), args)
-                               return call(tgs.first, recv, args)
+                               var res0 = before_send(mmethod, args)
+                               var res = call(tgs.first, tgs.first.mclassdef.bound_mtype, args)
+                               if res0 != null then
+                                       assert res != null
+                                       self.assign(res0, res)
+                                       res = res0
+                               end
+                               add("\}") # close the before_send
+                               return res
                        end
                end
                return super
@@ -1040,48 +1048,27 @@ class SeparateCompilerVisitor
                return table_send(mmethod, arguments, mmethod.const_color)
        end
 
-       private fun table_send(mmethod: MMethod, arguments: Array[RuntimeVariable], const_color: String): nullable RuntimeVariable
+       # Handel common special cases before doing the effective method invocation
+       # This methods handle the `==` and `!=` methods and the case of the null receiver.
+       # Note: a { is open in the generated C, that enclose and protect the effective method invocation.
+       # Client must not forget to close the } after them.
+       #
+       # The value returned is the result of the common special cases.
+       # If not null, client must compine it with the result of their own effective method invocation.
+       #
+       # If `before_send` can shortcut the whole message sending, a dummy `if(0){`
+       # is generated to cancel the effective method invocation that will follow
+       # TODO: find a better approach
+       private fun before_send(mmethod: MMethod, arguments: Array[RuntimeVariable]): nullable RuntimeVariable
        do
-               compiler.modelbuilder.nb_invok_by_tables += 1
-               if compiler.modelbuilder.toolcontext.opt_invocation_metrics.value then add("count_invoke_by_tables++;")
-
-               assert arguments.length == mmethod.intro.msignature.arity + 1 else debug("Invalid arity for {mmethod}. {arguments.length} arguments given.")
-
-               var res: nullable RuntimeVariable
-               var msignature = mmethod.intro.msignature.resolve_for(mmethod.intro.mclassdef.bound_mtype, mmethod.intro.mclassdef.bound_mtype, mmethod.intro.mclassdef.mmodule, true)
-               var ret = msignature.return_mtype
-               if mmethod.is_new then
-                       ret = arguments.first.mtype
-                       res = self.new_var(ret)
-               else if ret == null then
-                       res = null
-               else
-                       res = self.new_var(ret)
-               end
-
-               var s = new Buffer
-               var ss = new Buffer
-
+               var res: nullable RuntimeVariable = null
                var recv = arguments.first
-               s.append("val*")
-               ss.append("{recv}")
-               for i in [0..msignature.arity[ do
-                       var a = arguments[i+1]
-                       var t = msignature.mparameters[i].mtype
-                       if i == msignature.vararg_rank then
-                               t = arguments[i+1].mcasttype
-                       end
-                       s.append(", {t.ctype}")
-                       a = self.autobox(a, t)
-                       ss.append(", {a}")
-               end
-
                var consider_null = not self.compiler.modelbuilder.toolcontext.opt_no_check_other.value or mmethod.name == "==" or mmethod.name == "!="
                var maybenull = recv.mcasttype isa MNullableType and consider_null
                if maybenull then
                        self.add("if ({recv} == NULL) \{")
                        if mmethod.name == "==" then
-                               assert res != null
+                               res = self.new_var(bool_type)
                                var arg = arguments[1]
                                if arg.mcasttype isa MNullableType then
                                        self.add("{res} = ({arg} == NULL);")
@@ -1091,7 +1078,7 @@ class SeparateCompilerVisitor
                                        self.add("{res} = 0; /* {arg.inspect} cannot be null */")
                                end
                        else if mmethod.name == "!=" then
-                               assert res != null
+                               res = self.new_var(bool_type)
                                var arg = arguments[1]
                                if arg.mcasttype isa MNullableType then
                                        self.add("{res} = ({arg} != NULL);")
@@ -1104,9 +1091,11 @@ class SeparateCompilerVisitor
                                self.add_abort("Receiver is null")
                        end
                        self.add("\} else \{")
+               else
+                       self.add("\{")
                end
                if not self.compiler.modelbuilder.toolcontext.opt_no_shortcut_equate.value and (mmethod.name == "==" or mmethod.name == "!=") then
-                       assert res != null
+                       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)
                        var arg = arguments[1]
                        if arg.mcasttype isa MNullType then
@@ -1115,13 +1104,52 @@ class SeparateCompilerVisitor
                                else
                                        self.add("{res} = 1; /* arg is null and recv is not */")
                                end
-                               if maybenull then
-                                       self.add("\}")
-                               end
-                               return res
+                               self.add("\}") # closes the null case
+                               self.add("if (0) \{") # what follow is useless, CC will drop it
+                       end
+               end
+               return res
+       end
+
+       private fun table_send(mmethod: MMethod, arguments: Array[RuntimeVariable], const_color: String): nullable RuntimeVariable
+       do
+               compiler.modelbuilder.nb_invok_by_tables += 1
+               if compiler.modelbuilder.toolcontext.opt_invocation_metrics.value then add("count_invoke_by_tables++;")
+
+               assert arguments.length == mmethod.intro.msignature.arity + 1 else debug("Invalid arity for {mmethod}. {arguments.length} arguments given.")
+               var recv = arguments.first
+
+               var res0 = before_send(mmethod, arguments)
+
+               var res: nullable RuntimeVariable
+               var msignature = mmethod.intro.msignature.resolve_for(mmethod.intro.mclassdef.bound_mtype, mmethod.intro.mclassdef.bound_mtype, mmethod.intro.mclassdef.mmodule, true)
+               var ret = msignature.return_mtype
+               if mmethod.is_new then
+                       ret = arguments.first.mtype
+                       res = self.new_var(ret)
+               else if ret == null then
+                       res = null
+               else
+                       res = self.new_var(ret)
+               end
+
+               var s = new Buffer
+               var ss = new Buffer
+
+               s.append("val*")
+               ss.append("{recv}")
+               for i in [0..msignature.arity[ do
+                       var a = arguments[i+1]
+                       var t = msignature.mparameters[i].mtype
+                       if i == msignature.vararg_rank then
+                               t = arguments[i+1].mcasttype
                        end
+                       s.append(", {t.ctype}")
+                       a = self.autobox(a, t)
+                       ss.append(", {a}")
                end
 
+
                var r
                if ret == null then r = "void" else r = ret.ctype
                self.require_declaration(const_color)
@@ -1133,10 +1161,14 @@ class SeparateCompilerVisitor
                        self.add("{call};")
                end
 
-               if maybenull then
-                       self.add("\}")
+               if res0 != null then
+                       assert res != null
+                       assign(res0,res)
+                       res = res0
                end
 
+               self.add("\}") # closes the null case
+
                return res
        end