Re: Scheduling complete loop unrolling early and unconditional?

[Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>]

On Thu, 16 Dec 2004, David Edelsohn wrote:

> >>>>> Diego Novillo writes:
>
> Diego> Scheduling SRA after loop optimizations sounds better.  SRA should be
> Diego> able to run more than once.
>
> 	After some loop optimizations.  Increasing the granularity of the
> new loop optimizations could help with this overall goal.

Ok, scheduling another SRA after loop did not help.  Instead I scheduled
a complete unroll pass after the first dce run which works well for me.
Though I get garbled -ftime-report output.  Maybe I am not supposed to
re-use any of the struct passes??  I thought not.  It still works
only with -funroll-loops although I specified NULL gate for
pass_loop1 and pass_complete_unroll1.

Anyway, stuff is now scalarized nicely.  Patch below for anyone who is
interested.

Richard.


Index: tree-pass.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-pass.h,v
retrieving revision 2.22
diff -u -c -p -3 -r2.22 tree-pass.h
*** tree-pass.h	28 Nov 2004 21:02:31 -0000	2.22
--- tree-pass.h	16 Dec 2004 16:51:28 -0000
*************** extern struct tree_opt_pass pass_sra;
*** 125,130 ****
--- 125,131 ----
  extern struct tree_opt_pass pass_tail_recursion;
  extern struct tree_opt_pass pass_tail_calls;
  extern struct tree_opt_pass pass_loop;
+ extern struct tree_opt_pass pass_loop1;
  extern struct tree_opt_pass pass_loop_init;
  extern struct tree_opt_pass pass_lim;
  extern struct tree_opt_pass pass_unswitch;
*************** extern struct tree_opt_pass pass_iv_cano
*** 132,137 ****
--- 133,139 ----
  extern struct tree_opt_pass pass_record_bounds;
  extern struct tree_opt_pass pass_if_conversion;
  extern struct tree_opt_pass pass_vectorize;
+ extern struct tree_opt_pass pass_complete_unroll1;
  extern struct tree_opt_pass pass_complete_unroll;
  extern struct tree_opt_pass pass_iv_optimize;
  extern struct tree_opt_pass pass_loop_done;
Index: tree-optimize.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-optimize.c,v
retrieving revision 2.65
diff -u -c -p -3 -r2.65 tree-optimize.c
*** tree-optimize.c	30 Nov 2004 15:38:33 -0000	2.65
--- tree-optimize.c	16 Dec 2004 16:51:28 -0000
*************** init_tree_optimization_passes (void)
*** 351,356 ****
--- 351,357 ----
    NEXT_PASS (pass_rename_ssa_copies);
    NEXT_PASS (pass_early_warn_uninitialized);
    NEXT_PASS (pass_dce);
+   NEXT_PASS (pass_loop1);
    NEXT_PASS (pass_dominator);
    NEXT_PASS (pass_redundant_phi);
    NEXT_PASS (pass_dce);
*************** init_tree_optimization_passes (void)
*** 407,412 ****
--- 408,419 ----
    NEXT_PASS (pass_loop_done);
    *p = NULL;

+   p = &pass_loop1.sub;
+   NEXT_PASS (pass_loop_init);
+   NEXT_PASS (pass_complete_unroll1);
+   NEXT_PASS (pass_loop_done);
+   *p = NULL;
+
  #undef NEXT_PASS

    /* Register the passes with the tree dump code.  */
Index: tree-ssa-loop.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-ssa-loop.c,v
retrieving revision 2.23
diff -u -c -p -3 -r2.23 tree-ssa-loop.c
*** tree-ssa-loop.c	26 Nov 2004 06:42:25 -0000	2.23
--- tree-ssa-loop.c	16 Dec 2004 16:51:28 -0000
*************** struct tree_opt_pass pass_loop =
*** 93,98 ****
--- 93,115 ----
    0					/* letter */
  };

+ struct tree_opt_pass pass_loop1 =
+ {
+   "loop1",				/* name */
+   NULL,					/* gate */
+   NULL,					/* execute */
+   NULL,					/* sub */
+   NULL,					/* next */
+   0,					/* static_pass_number */
+   TV_TREE_LOOP,				/* tv_id */
+   PROP_cfg,				/* properties_required */
+   0,					/* properties_provided */
+   0,					/* properties_destroyed */
+   TODO_ggc_collect,			/* todo_flags_start */
+   TODO_dump_func | TODO_verify_ssa | TODO_ggc_collect,	/* todo_flags_finish */
+   0					/* letter */
+ };
+
  /* Loop optimizer initialization.  */

  static void
*************** struct tree_opt_pass pass_complete_unrol
*** 360,365 ****
--- 377,399 ----
    0					/* letter */
  };

+ struct tree_opt_pass pass_complete_unroll1 =
+ {
+   "cunroll1",				/* name */
+   NULL,					/* gate */
+   tree_complete_unroll,		       	/* execute */
+   NULL,					/* sub */
+   NULL,					/* next */
+   0,					/* static_pass_number */
+   TV_COMPLETE_UNROLL,	  		/* tv_id */
+   PROP_cfg | PROP_ssa,			/* properties_required */
+   0,					/* properties_provided */
+   0,					/* properties_destroyed */
+   0,					/* todo_flags_start */
+   TODO_dump_func,                	/* todo_flags_finish */
+   0					/* letter */
+ };
+
  /* Induction variable optimizations.  */

  static void