Re: [rfc] Fix SPU build (Re: [PATCH] Remove basic_block->loop_depth)

["Ulrich Weigand" <uweigand@de.ibm.com>]

Richard Guenther wrote:
> On Wed, 15 Aug 2012, Ulrich Weigand wrote:
> > It seems flow_loops_find by itself is not quite enough, but everything
> > necessary to use the loop structures seems to be encapsulated in
> > loop_optimizer_init / loop_optimizer_finalize, which are already called
> > by a number of optimization passes.  When I do the same in the SPU
> > md-reorg pass, loop_father seems to be set up OK.
> > 
> > Does this look reasonable?
> 
> Yes.  You can use bb_loop_depth instead of loop_depth (bb->loop_father).

Ah, good point.  Below the version I committed.  Tested on spu-elf.

Thanks,
Ulrich

ChangeLog:

	* config/spu/spu.c: Include "cfgloop.h".
	(spu_machine_dependent_reorg): Call loop_optimizer_init and
	loop_optimizer_finalize.  Use bb_loop_depth instead of loop_depth.
	Directly compare loop_father values where appropriate.
	* config/spu/t-spu-elf (spu.o): Update dependencies.

Index: gcc/config/spu/spu.c
===================================================================
*** gcc/config/spu/spu.c	(revision 190390)
--- gcc/config/spu/spu.c	(working copy)
***************
*** 53,58 ****
--- 53,59 ----
  #include "timevar.h"
  #include "df.h"
  #include "dumpfile.h"
+ #include "cfgloop.h"
  
  /* Builtin types, data and prototypes. */
  
*************** spu_machine_dependent_reorg (void)
*** 2458,2463 ****
--- 2459,2468 ----
    in_spu_reorg = 1;
    compute_bb_for_insn ();
  
+   /* (Re-)discover loops so that bb->loop_father can be used
+      in the analysis below.  */
+   loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
+ 
    compact_blocks ();
  
    spu_bb_info =
*************** spu_machine_dependent_reorg (void)
*** 2562,2575 ****
  	     fallthru block. This catches the cases when it is a simple
  	     loop or when there is an initial branch into the loop. */
  	  if (prev && (loop_exit || simple_loop)
! 	      && prev->loop_depth <= bb->loop_depth)
  	    prop = prev;
  
  	  /* If there is only one adjacent predecessor.  Don't propagate
! 	     outside this loop.  This loop_depth test isn't perfect, but
! 	     I'm not sure the loop_father member is valid at this point.  */
  	  else if (prev && single_pred_p (bb)
! 		   && prev->loop_depth == bb->loop_depth)
  	    prop = prev;
  
  	  /* If this is the JOIN block of a simple IF-THEN then
--- 2567,2579 ----
  	     fallthru block. This catches the cases when it is a simple
  	     loop or when there is an initial branch into the loop. */
  	  if (prev && (loop_exit || simple_loop)
! 	      && bb_loop_depth (prev) <= bb_loop_depth (bb))
  	    prop = prev;
  
  	  /* If there is only one adjacent predecessor.  Don't propagate
! 	     outside this loop.  */
  	  else if (prev && single_pred_p (bb)
! 		   && prev->loop_father == bb->loop_father)
  	    prop = prev;
  
  	  /* If this is the JOIN block of a simple IF-THEN then
*************** spu_machine_dependent_reorg (void)
*** 2578,2584 ****
  		   && EDGE_COUNT (bb->preds) == 2
  		   && EDGE_COUNT (prev->preds) == 1
  		   && EDGE_PRED (prev, 0)->src == prev2
! 		   && prev2->loop_depth == bb->loop_depth
  		   && GET_CODE (branch_target) != REG)
  	    prop = prev;
  
--- 2582,2588 ----
  		   && EDGE_COUNT (bb->preds) == 2
  		   && EDGE_COUNT (prev->preds) == 1
  		   && EDGE_PRED (prev, 0)->src == prev2
! 		   && prev2->loop_father == bb->loop_father
  		   && GET_CODE (branch_target) != REG)
  	    prop = prev;
  
*************** spu_machine_dependent_reorg (void)
*** 2600,2606 ****
  	      if (dump_file)
  		fprintf (dump_file, "propagate from %i to %i (loop depth %i) "
  			 "for %i (loop_exit %i simple_loop %i dist %i)\n",
! 			 bb->index, prop->index, bb->loop_depth,
  			 INSN_UID (branch), loop_exit, simple_loop,
  			 branch_addr - INSN_ADDRESSES (INSN_UID (bbend)));
  
--- 2604,2610 ----
  	      if (dump_file)
  		fprintf (dump_file, "propagate from %i to %i (loop depth %i) "
  			 "for %i (loop_exit %i simple_loop %i dist %i)\n",
! 			 bb->index, prop->index, bb_loop_depth (bb),
  			 INSN_UID (branch), loop_exit, simple_loop,
  			 branch_addr - INSN_ADDRESSES (INSN_UID (bbend)));
  
*************** spu_machine_dependent_reorg (void)
*** 2657,2662 ****
--- 2661,2668 ----
  
    spu_var_tracking ();
  
+   loop_optimizer_finalize ();
+ 
    free_bb_for_insn ();
  
    in_spu_reorg = 0;
Index: gcc/config/spu/t-spu-elf
===================================================================
*** gcc/config/spu/t-spu-elf	(revision 190390)
--- gcc/config/spu/t-spu-elf	(working copy)
*************** spu.o: $(CONFIG_H) $(SYSTEM_H) coretypes
*** 23,29 ****
    real.h insn-config.h conditions.h insn-attr.h flags.h $(RECOG_H) \
    $(OBSTACK_H) $(TREE_H) $(EXPR_H) $(OPTABS_H) except.h function.h \
    output.h $(BASIC_BLOCK_H) $(GGC_H) $(HASHTAB_H) \
!   $(TM_P_H) $(TARGET_H) $(TARGET_DEF_H) langhooks.h reload.h \
    $(srcdir)/config/spu/spu-protos.h \
    $(srcdir)/config/spu/spu-builtins.def 
  
--- 23,29 ----
    real.h insn-config.h conditions.h insn-attr.h flags.h $(RECOG_H) \
    $(OBSTACK_H) $(TREE_H) $(EXPR_H) $(OPTABS_H) except.h function.h \
    output.h $(BASIC_BLOCK_H) $(GGC_H) $(HASHTAB_H) \
!   $(TM_P_H) $(TARGET_H) $(TARGET_DEF_H) langhooks.h reload.h $(CFGLOOP_H) \
    $(srcdir)/config/spu/spu-protos.h \
    $(srcdir)/config/spu/spu-builtins.def 
  


-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com