sep_compiler: add option --substitute-monomorph to substitute monomorph trampoline...

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/compiler/separate_compiler.nit b/src/compiler/separate_compiler.nit
index 6b7a004..e0cfd98 100644 (file)
--- a/src/compiler/separate_compiler.nit
+++ b/src/compiler/separate_compiler.nit
@@ -33,6 +33,8 @@ redef class ToolContext
        var opt_colors_are_symbols = new OptionBool("Store colors as symbols (faster)", "--colors-are-symbols")
        # --trampoline-call
        var opt_trampoline_call = new OptionBool("Use an indirection when calling", "--trampoline-call")
+       # --substitute-monomorph
+       var opt_substitute_monomorph = new OptionBool("Replace monomorph trampoline with direct call", "--substitute-monomorph")
 
        # --inline-coloring-numbers
        var opt_inline_coloring_numbers = new OptionBool("Inline colors and ids (semi-global)", "--inline-coloring-numbers")
@@ -55,7 +57,7 @@ redef class ToolContext
                self.option_context.add_option(self.opt_separate)
                self.option_context.add_option(self.opt_no_inline_intern)
                self.option_context.add_option(self.opt_no_union_attribute)
-               self.option_context.add_option(self.opt_no_shortcut_equate, opt_colors_are_symbols, opt_trampoline_call)
+               self.option_context.add_option(self.opt_no_shortcut_equate, opt_colors_are_symbols, opt_trampoline_call, opt_substitute_monomorph)
                self.option_context.add_option(self.opt_inline_coloring_numbers, opt_inline_some_methods, opt_direct_call_monomorph, opt_skip_dead_methods, opt_semi_global)
                self.option_context.add_option(self.opt_colo_dead_methods)
                self.option_context.add_option(self.opt_tables_metrics)
@@ -567,6 +569,24 @@ class SeparateCompiler
                                # Generate trampolines
                                if modelbuilder.toolcontext.opt_trampoline_call.value then
                                        r2.compile_trampolines(self)
+
+                                       # Replace monomorphic call to a trampoline by a direct call to the virtual implementation
+                                       if modelbuilder.toolcontext.opt_substitute_monomorph.value then do
+                                               var m = pd.mproperty
+                                               if rta == null then
+                                                       # Without RTA, monomorphic means alone (uniq name)
+                                                       if m.mpropdefs.length != 1 then break label
+                                               else
+                                                       # With RTA, monomorphic means only live methoddef
+                                                       if not rta.live_methoddefs.has(pd) then break label
+                                                       for md in m.mpropdefs do
+                                                               if md != pd and rta.live_methoddefs.has(md) then break label
+                                                       end
+                                               end
+                                               # Here the trick, GNU ld can substitute symbols with specific values.
+                                               var n2 = "CALL_" + m.const_color
+                                               linker_script.add("{n2} = {r2.c_name};")
+                                       end label
                                end
                        end
                end