vm_core.h (struct rb_iseq_struct): stack_max is uint32_t

* vm_core.h (struct rb_iseq_struct): stack_max is uint32_t
  No program will ever need more than a few megabytes of stack,
  so there's no sense in using a 64-bit counter for stack
  accounting.  Packing this with the 32-bit type enum reduces
  rb_iseq_struct from 312 to 304 bytes on 64-bit systems.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46798 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Sun Jul 13 15:53:25 2014  Eric Wong  <e@80x24.org>
+
+	* vm_core.h (struct rb_iseq_struct): stack_max is uint32_t
+
 Sun Jul 13 10:56:26 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* configure.in (rb_cv_broken_backtrace): exit with failure

vm_core.h

@@ -204,6 +204,7 @@ struct rb_iseq_struct {
 	ISEQ_TYPE_MAIN,
 	ISEQ_TYPE_DEFINED_GUARD
     } type;              /* instruction sequence type */
+    uint32_t stack_max; /* for stack overflow check */
 
     rb_iseq_location_t location;
 
@@ -271,8 +272,6 @@ struct rb_iseq_struct {
     int arg_keyword_required;
     ID *arg_keyword_table;
 
-    size_t stack_max; /* for stack overflow check */
-
     /* catch table */
     struct iseq_catch_table_entry *catch_table;
     int catch_table_size;