[PATCH] rearrange struct value to save memory

[Tom Tromey <tromey@redhat.com>]

This patch rearranges struct value a tiny bit, moving the "regnum"
field into a hole.  This saves 8 bytes per value on a 64-bit machine,
and 4 bytes per value on a 32 bit machine.  I think it does not
negatively affect readability or performance.

Built and regtested on x86-64 Fedora 18.

Let me know what you think.

2014-01-09  Tom Tromey  <tromey@redhat.com>

	* value.c (struct value) <regnum>: Move earlier.
---
 gdb/ChangeLog | 4 ++++
 gdb/value.c   | 6 +++---
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/gdb/value.c b/gdb/value.c
index 8542316..0e13b76 100644
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -216,6 +216,9 @@ struct value
   /* If the value has been released.  */
   unsigned int released : 1;
 
+  /* Register number if the value is from a register.  */
+  short regnum;
+
   /* Location of value (if lval).  */
   union
   {
@@ -324,9 +327,6 @@ struct value
      taken off this list.  */
   struct value *next;
 
-  /* Register number if the value is from a register.  */
-  short regnum;
-
   /* Actual contents of the value.  Target byte-order.  NULL or not
      valid if lazy is nonzero.  */
   gdb_byte *contents;
-- 
1.8.1.4