Re: GC special object sizes

[Steven Bosscher <s dot bosscher at student dot tudelft dot nl>]

Op di 29-04-2003, om 20:36 schreef Steven Bosscher:
> Op di 29-04-2003, om 20:31 schreef Geoff Keating:
> > That's a good question.  A good thing to do next would be to try
> > adding such a page (for trees with two operands) and see whether it
> > helps or hurts performance.

With the attached patch I get just over 1% better with checking
enabled.  You think that's worth it?

Bootstrapped and regtested on i586-pc-linux-gnu.  Timed by compiling g95
(~75000 lines) three times at -O3 with and without the patch.  Goes from
89.5s avarage to 88.2s.  OK?

Diego, you get this because if this goes on the trunk, you should _not_
merge it into the tree-ssa branch, because tree_common is 8 bytes larger
on the branch, so two operand tree_exps are 32 bytes.

Greetz
Steven


2003-04-30  Steven Bosscher  <steven@gcc.gnu.org>

	* ggc-page.c (TREE_EXP_SIZE): Define.
	(extra_order_size_table): New entry for expr trees with
	two operands.


Index: ggc-page.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ggc-page.c,v
retrieving revision 1.64
diff -c -3 -p -r1.64 ggc-page.c
*** ggc-page.c	17 Mar 2003 18:42:23 -0000	1.64
--- ggc-page.c	30 Apr 2003 15:05:24 -0000
*************** Software Foundation, 59 Temple Place - S
*** 173,178 ****
--- 173,181 ----
  #define RTL_SIZE(NSLOTS) \
    (sizeof (struct rtx_def) + ((NSLOTS) - 1) * sizeof (rtunion))
  
+ #define TREE_EXP_SIZE(OPS) \
+   (sizeof (struct tree_exp) + ((OPS) - 1) * sizeof (tree))
+ 
  /* The Ith entry is the maximum size of an object to be stored in the
     Ith extra order.  Adding a new entry to this array is the *only*
     thing you need to do to add a new special allocation size.  */
*************** Software Foundation, 59 Temple Place - S
*** 180,185 ****
--- 183,189 ----
  static const size_t extra_order_size_table[] = {
    sizeof (struct tree_decl),
    sizeof (struct tree_list),
+   TREE_EXP_SIZE (2),
    RTL_SIZE (2),			/* REG, MEM, PLUS, etc.  */
    RTL_SIZE (10),		/* INSN, CALL_INSN, JUMP_INSN */
  };