[PATCH 2/2] better packing for command struct

[Tom Tromey <tromey at redhat dot com>]

This moves all the bitfields in struct cmd_list_element to be closer
together.  This packs the structure somewhat better.  On a 64 bit
machine, this simple rearrangement saves around 50k at startup.

2014-01-13  Tom Tromey  <tromey@redhat.com>

	* cli/cli-decode.h (struct cmd_list_element): Move all bitfields
	together.
---
 gdb/ChangeLog        |  5 +++
 gdb/cli/cli-decode.h | 96 ++++++++++++++++++++++++++--------------------------
 2 files changed, 53 insertions(+), 48 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2862b3f..89d975c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2014-01-13  Tom Tromey  <tromey@redhat.com>
 
+	* cli/cli-decode.h (struct cmd_list_element): Move all bitfields
+	together.
+
+2014-01-13  Tom Tromey  <tromey@redhat.com>
+
 	* cli/cli-decode.c (add_cmd, deprecate_cmd, add_alias_cmd)
 	(add_setshow_cmd_full, delete_cmd, lookup_cmd_1)
 	(deprecated_cmd_warning, complete_on_cmdlist): Update.
diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
index 10ff36d..c6edc87 100644
--- a/gdb/cli/cli-decode.h
+++ b/gdb/cli/cli-decode.h
@@ -55,6 +55,54 @@ struct cmd_list_element
     /* Command class; class values are chosen by application program.  */
     enum command_class class;
 
+    /* When 1 indicated that this command is deprecated.  It may be
+       removed from gdb's command set in the future.  */
+
+    unsigned int cmd_deprecated : 1;
+
+    /* The user needs to be warned that this is a deprecated command.
+       The user should only be warned the first time a command is
+       used.  */
+        
+    unsigned int deprecated_warn_user : 1;
+
+    /* When functions are deprecated at compile time (this is the way
+       it should, in general, be done) the memory containing the
+       replacement string is statically allocated.  In some cases it
+       makes sense to deprecate commands at runtime (the testsuite is
+       one example).  In this case the memory for replacement is
+       malloc'ed.  When a command is undeprecated or re-deprecated at
+       runtime we don't want to risk calling free on statically
+       allocated memory, so we check this flag.  */
+
+    unsigned int malloced_replacement : 1;
+
+    /* Set if the doc field should be xfree'd.  */
+
+    unsigned int doc_allocated : 1;
+
+    /* Flag that specifies if this command is already running its hook.  */
+    /* Prevents the possibility of hook recursion.  */
+    unsigned int hook_in : 1;
+
+    /* For prefix commands only:
+       nonzero means do not get an error if subcommand is not
+       recognized; call the prefix's own function in that case.  */
+    unsigned int allow_unknown : 1;
+
+    /* Nonzero says this is an abbreviation, and should not
+       be mentioned in lists of commands.
+       This allows "br<tab>" to complete to "break", which it
+       otherwise wouldn't.  */
+    unsigned int abbrev_flag : 1;
+
+    /* Type of "set" or "show" command (or SET_NOT_SET if not "set"
+       or "show").  */
+    ENUM_BITFIELD (cmd_types) type : 2;
+
+    /* What kind of variable is *VAR?  */
+    ENUM_BITFIELD (var_types) var_type : 4;
+
     /* Function definition of this command.  NULL for command class
        names and for help topics that are not really commands.  NOTE:
        cagney/2002-02-02: This function signature is evolving.  For
@@ -86,32 +134,6 @@ struct cmd_list_element
        specified stream.  */
     show_value_ftype *show_value_func;
 
-    /* When 1 indicated that this command is deprecated.  It may be
-       removed from gdb's command set in the future.  */
-
-    unsigned int cmd_deprecated : 1;
-
-    /* The user needs to be warned that this is a deprecated command.
-       The user should only be warned the first time a command is
-       used.  */
-        
-    unsigned int deprecated_warn_user : 1;
-
-    /* When functions are deprecated at compile time (this is the way
-       it should, in general, be done) the memory containing the
-       replacement string is statically allocated.  In some cases it
-       makes sense to deprecate commands at runtime (the testsuite is
-       one example).  In this case the memory for replacement is
-       malloc'ed.  When a command is undeprecated or re-deprecated at
-       runtime we don't want to risk calling free on statically
-       allocated memory, so we check this flag.  */
-
-    unsigned int malloced_replacement : 1;
-
-    /* Set if the doc field should be xfree'd.  */
-
-    unsigned int doc_allocated : 1;
-
     /* If this command is deprecated, this is the replacement name.  */
     char *replacement;
 
@@ -122,10 +144,6 @@ struct cmd_list_element
     /* Hook for another command to be executed before this command.  */
     struct cmd_list_element *hook_pre;
 
-    /* Flag that specifies if this command is already running its hook.  */
-    /* Prevents the possibility of hook recursion.  */
-    unsigned int hook_in : 1;
-
     /* Hook for another command to be executed after this command.  */
     struct cmd_list_element *hook_post;
 
@@ -140,20 +158,9 @@ struct cmd_list_element
        commands reached through this prefix.  */
     char *prefixname;
 
-    /* For prefix commands only:
-       nonzero means do not get an error if subcommand is not
-       recognized; call the prefix's own function in that case.  */
-    unsigned int allow_unknown : 1;
-
     /* The prefix command of this command.  */
     struct cmd_list_element *prefix;
 
-    /* Nonzero says this is an abbreviation, and should not
-       be mentioned in lists of commands.
-       This allows "br<tab>" to complete to "break", which it
-       otherwise wouldn't.  */
-    unsigned int abbrev_flag : 1;
-
     /* Completion routine for this command.  TEXT is the text beyond
        what was matched for the command itself (leading whitespace is
        skipped).  It stops where we are supposed to stop completing
@@ -174,17 +181,10 @@ struct cmd_list_element
        used to finalize the CONTEXT field, if needed.  */
     void (*destroyer) (struct cmd_list_element *self, void *context);
 
-    /* Type of "set" or "show" command (or SET_NOT_SET if not "set"
-       or "show").  */
-    ENUM_BITFIELD (cmd_types) type : 2;
-
     /* Pointer to variable affected by "set" and "show".  Doesn't
        matter if type is not_set.  */
     void *var;
 
-    /* What kind of variable is *VAR?  */
-    ENUM_BITFIELD (var_types) var_type : 4;
-
     /* Pointer to NULL terminated list of enumerated values (like
        argv).  */
     const char *const *enums;
-- 
1.8.1.4