vm_exec.h: introduce macros for abstarction.

* vm_exec.h: declare two macros
  * START_OF_ORIGINAL_INSN()
  * DISPATCH_ORIGINAL_INSN()
  instead of inserting label and goto lines.
  For OPT_CALL_THREADED_CODE, first macro is empty and second macro
  is simply call the original insn function.

* tool/instruction.rb: use above macros.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61120 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

tool/instruction.rb

@@ -540,7 +540,7 @@ class RubyVM
       @insns.dup.each{|insn|
         body = <<-EOS
         vm_trace(ec, GET_CFP(), GET_PC());
-        goto start_of_#{insn.name};
+        DISPATCH_ORIGINAL_INSN(#{insn.name});
         EOS
 
         trace_insn = Instruction.new(name = "trace_#{insn.name}",
@@ -884,7 +884,7 @@ class RubyVM
     end
 
     def make_header insn
-      label = insn.trace ? '' : "start_of_#{insn.name}:;"
+      label = insn.trace ? '' : "START_OF_ORIGINAL_INSN(#{insn.name});"
       commit "INSN_ENTRY(#{insn.name}){#{label}"
       make_header_prepare_stack insn
       commit "{"

vm_exec.h

@@ -66,6 +66,9 @@ error !
 
 #define NEXT_INSN() return reg_cfp;
 
+#define START_OF_ORIGINAL_INSN(x) /* ignore */
+#define DISPATCH_ORIGINAL_INSN(x) return LABEL(x)(ec, reg_cfp);
+
 /************************************************/
 #elif OPT_TOKEN_THREADED_CODE || OPT_DIRECT_THREADED_CODE
 /* threaded code with gcc */
@@ -95,10 +98,8 @@ error !
 #else
 #define DISPATCH_ARCH_DEPEND_WAY(addr) \
 				/* do nothing */
-
 #endif
 
-
 /**********************************/
 #if OPT_DIRECT_THREADED_CODE
 
@@ -134,6 +135,9 @@ error !
 
 #define NEXT_INSN() TC_DISPATCH(__NEXT_INSN__)
 
+#define START_OF_ORIGINAL_INSN(x) start_of_##x:
+#define DISPATCH_ORIGINAL_INSN(x) goto  start_of_##x;
+
 /************************************************/
 #else /* no threaded code */
 /* most common method */
@@ -145,7 +149,6 @@ case BIN(insn):
   DEBUG_END_INSN();                           \
   break;
 
-
 #define INSN_DISPATCH()         \
   while (1) {			\
     switch (GET_CURRENT_INSN()) {
@@ -159,6 +162,9 @@ default:                        \
 
 #define NEXT_INSN() goto first
 
+#define START_OF_ORIGINAL_INSN(x) start_of_##x:
+#define DISPATCH_ORIGINAL_INSN(x) goto  start_of_##x;
+
 #endif
 
 #define VM_SP_CNT(ec, sp) ((sp) - (ec)->vm_stack)