move register renaming before sched2

[Stan Cox <scox at cygnus dot com>]

This patch moves register renaming before sched2.  It also improves the
REG_DEAD handling in insns containing renamed registers.

2000-05-10 Stan Cox <scox@cygnus.com>

	* regrename.c (replace_reg_in_block): Improve REG_DEAD handling.
	* timevar.def (TV_RENAME_REGISTERS): Move before TV_SCHED2.
	* toplev.c (rest_of_compilation): Call regrename_optimize before sched2.

Index: timevar.def
===================================================================
RCS file: /cvs/gcc/egcs/gcc/timevar.def,v
retrieving revision 1.2
diff -c -2 -p -r1.2 timevar.def
*** timevar.def	2000/04/30 11:01:53	1.2
--- timevar.def	2000/05/11 01:13:31
*************** DEFTIMEVAR (TV_FLOW2                 , "
*** 61,68 ****
  DEFTIMEVAR (TV_IFCVT2		     , "if-conversion 2")
  DEFTIMEVAR (TV_PEEPHOLE2             , "peephole 2")
! DEFTIMEVAR (TV_SCHED2                , "schedulding 2")
  DEFTIMEVAR (TV_DBR_SCHED             , "delay branch sched")
  DEFTIMEVAR (TV_REORDER_BLOCKS        , "reorder blocks")
- DEFTIMEVAR (TV_RENAME_REGISTERS      , "rename registers")
  DEFTIMEVAR (TV_SHORTEN_BRANCH        , "shorten branches")
  DEFTIMEVAR (TV_REG_STACK             , "reg stack")
--- 61,68 ----
  DEFTIMEVAR (TV_IFCVT2		     , "if-conversion 2")
  DEFTIMEVAR (TV_PEEPHOLE2             , "peephole 2")
! DEFTIMEVAR (TV_RENAME_REGISTERS      , "rename registers")
! DEFTIMEVAR (TV_SCHED2                , "scheduling 2")
  DEFTIMEVAR (TV_DBR_SCHED             , "delay branch sched")
  DEFTIMEVAR (TV_REORDER_BLOCKS        , "reorder blocks")
  DEFTIMEVAR (TV_SHORTEN_BRANCH        , "shorten branches")
  DEFTIMEVAR (TV_REG_STACK             , "reg stack")
Index: toplev.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/toplev.c,v
retrieving revision 1.333
diff -c -2 -p -r1.333 toplev.c
*** toplev.c	2000/05/09 19:55:48	1.333
--- toplev.c	2000/05/11 01:13:35
*************** enum dump_file_index
*** 273,279 ****
    DFI_ce2,
    DFI_peephole2,
    DFI_sched2,
    DFI_bbro,
-   DFI_rnreg,
    DFI_jump2,
    DFI_mach,
--- 273,279 ----
    DFI_ce2,
    DFI_peephole2,
+   DFI_rnreg,
    DFI_sched2,
    DFI_bbro,
    DFI_jump2,
    DFI_mach,
*************** struct dump_file_info dump_file[DFI_MAX]
*** 315,321 ****
    { "ce2",	'E', 1, 0, 0 },
    { "peephole2", 'z', 1, 0, 0 },
    { "sched2",	'R', 1, 0, 0 },
    { "bbro",	'B', 1, 0, 0 },
-   { "rnreg",	'n', 1, 0, 0 },
    { "jump2",	'J', 1, 0, 0 },
    { "mach",	'M', 1, 0, 0 },
--- 315,321 ----
    { "ce2",	'E', 1, 0, 0 },
    { "peephole2", 'z', 1, 0, 0 },
+   { "rnreg",	'n', 1, 0, 0 },
    { "sched2",	'R', 1, 0, 0 },
    { "bbro",	'B', 1, 0, 0 },
    { "jump2",	'J', 1, 0, 0 },
    { "mach",	'M', 1, 0, 0 },
*************** rest_of_compilation (decl)
*** 3358,3362 ****
        life_analysis (insns, rtl_dump_file, PROP_FINAL);
  
!       /* This is kind of heruistics.  We need to run combine_stack_adjustments
           even for machines with possibly nonzero RETURN_POPS_ARGS
           and ACCUMULATE_OUTGOING_ARGS.  We expect that only ports having
--- 3358,3362 ----
        life_analysis (insns, rtl_dump_file, PROP_FINAL);
  
!       /* This is kind of a heuristic.  We need to run combine_stack_adjustments
           even for machines with possibly nonzero RETURN_POPS_ARGS
           and ACCUMULATE_OUTGOING_ARGS.  We expect that only ports having
*************** rest_of_compilation (decl)
*** 3400,3403 ****
--- 3400,3414 ----
  #endif
  
+   if (optimize > 0 && flag_rename_registers)
+     {
+       timevar_push (TV_RENAME_REGISTERS);
+       open_dump_file (DFI_rnreg, decl);
+ 
+       regrename_optimize ();
+ 
+       close_dump_file (DFI_rnreg, print_rtl_with_bb, insns);
+       timevar_pop (TV_RENAME_REGISTERS);
+     }    
+ 
  #ifdef INSN_SCHEDULING
    if (optimize > 0 && flag_schedule_insns_after_reload)
*************** rest_of_compilation (decl)
*** 3433,3447 ****
        close_dump_file (DFI_bbro, print_rtl_with_bb, insns);
        timevar_pop (TV_REORDER_BLOCKS);
-     }    
- 
-   if (optimize > 0 && flag_rename_registers)
-     {
-       timevar_push (TV_RENAME_REGISTERS);
-       open_dump_file (DFI_rnreg, decl);
- 
-       regrename_optimize ();
- 
-       close_dump_file (DFI_rnreg, print_rtl_with_bb, insns);
-       timevar_pop (TV_RENAME_REGISTERS);
      }    
  
--- 3444,3447 ----

Index: regrename.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/regrename.c,v
retrieving revision 1.5
diff -c -2 -p -r1.5 regrename.c
*** regrename.c	2000/04/10 11:23:17	1.5
--- regrename.c	2000/05/11 01:13:31
*************** replace_reg_in_block (du, uid_ruid, def,
*** 527,532 ****
--- 527,535 ----
  {
    int du_idx, status = 1;
+   int last_replaced_insn;
    unsigned int r = REGNO (reg_def);
    rtx death_note;
+   rtx reg_notes;
+   rtx reg_use;
    rtx new_reg = gen_rtx_REG (GET_MODE (reg_def), avail_reg);
  
*************** replace_reg_in_block (du, uid_ruid, def,
*** 537,561 ****
      return status;
  
!   death_note = find_reg_note (VARRAY_RTX (*uid_ruid, def), REG_DEAD, reg_def);
!   if (!death_note)
!     death_note = find_reg_note (VARRAY_RTX (*uid_ruid, def), REG_UNUSED,
! 				reg_def);
  
    if (death_note)
!     rr_replace_reg (death_note, reg_def, new_reg, 0,
! 		    VARRAY_RTX (*uid_ruid, def), &status);
  
    for (du_idx = def + 1; du_idx < du->high_bound; du_idx++)
      {
-       rtx reg_use;
-       rtx new_reg;
- 
        if (GET_RTX_CLASS (GET_CODE (VARRAY_RTX (*uid_ruid, du_idx))) != 'i')
  	continue;
  
        reg_use = regno_use_in (r, PATTERN (VARRAY_RTX (*uid_ruid, du_idx)));
        if (reg_use && TEST_BIT (du->uses[r], du_idx))
  	{
  	  new_reg = gen_rtx_REG (GET_MODE (reg_use), avail_reg);
  	  rr_replace_reg (PATTERN (VARRAY_RTX (*uid_ruid, du_idx)), reg_use,
  			  new_reg, SOURCE, VARRAY_RTX (*uid_ruid, du_idx),
--- 540,578 ----
      return status;
  
!   death_note = 0;
!   /* This typically happens if a constraint check failed and the register
!      changes are being reversed. */
!   for (reg_notes = REG_NOTES (VARRAY_RTX (*uid_ruid, def));
!        reg_notes; reg_notes = XEXP (reg_notes, 1))
!     {
!       if (REG_NOTE_KIND (reg_notes) == REG_DEAD
! 	  && REGNO (XEXP (reg_notes, 0)) == avail_reg)
! 	death_note = reg_notes;
!     }
  
    if (death_note)
!     remove_note (VARRAY_RTX (*uid_ruid, def), death_note);
!   
!   /* The old destination is now dead if it is also a source. */
!   if (regno_use_in (r, PATTERN (VARRAY_RTX (*uid_ruid, def))))
!     REG_NOTES (VARRAY_RTX (*uid_ruid, def))
!       = gen_rtx_EXPR_LIST (REG_DEAD, reg_def,
! 			   REG_NOTES (VARRAY_RTX (*uid_ruid,
! 						  def)));
  
+   last_replaced_insn = 0;
+ 
+   /* Now replace in the uses. */
    for (du_idx = def + 1; du_idx < du->high_bound; du_idx++)
      {
        if (GET_RTX_CLASS (GET_CODE (VARRAY_RTX (*uid_ruid, du_idx))) != 'i')
  	continue;
  
        reg_use = regno_use_in (r, PATTERN (VARRAY_RTX (*uid_ruid, du_idx)));
+ 
        if (reg_use && TEST_BIT (du->uses[r], du_idx))
  	{
  	  new_reg = gen_rtx_REG (GET_MODE (reg_use), avail_reg);
+ 	  
  	  rr_replace_reg (PATTERN (VARRAY_RTX (*uid_ruid, du_idx)), reg_use,
  			  new_reg, SOURCE, VARRAY_RTX (*uid_ruid, du_idx),
*************** replace_reg_in_block (du, uid_ruid, def,
*** 563,573 ****
  	  death_note = find_reg_note (VARRAY_RTX (*uid_ruid, du_idx),
  				      REG_DEAD, reg_use);
- 	  if (!death_note)
- 	    death_note = find_reg_note (VARRAY_RTX (*uid_ruid, du_idx),
- 					REG_UNUSED, reg_use);
  	  if (death_note)
! 	    rr_replace_reg (death_note, reg_use, new_reg, 0,
! 			    VARRAY_RTX (*uid_ruid, def), &status);
  
  	  SET_BIT (du->uses[avail_reg], du_idx);
  	  RESET_BIT (du->uses[r], du_idx);
--- 580,601 ----
  	  death_note = find_reg_note (VARRAY_RTX (*uid_ruid, du_idx),
  				      REG_DEAD, reg_use);
  	  if (death_note)
! 	    {
! 	      REG_NOTES (VARRAY_RTX (*uid_ruid, du_idx))
! 		= gen_rtx_EXPR_LIST (REG_DEAD, new_reg,
! 				     REG_NOTES (VARRAY_RTX (*uid_ruid,
! 							    du_idx)));
! 	      remove_note (VARRAY_RTX (*uid_ruid, du_idx),
! 			   find_reg_note (VARRAY_RTX (*uid_ruid, du_idx),
! 					  REG_DEAD, reg_use));
! 	    }
! 	}
  
+       /* This insn may contain shared rtl replaced in the previous iteration.
+ 	 Treat this equivalent to the rr_replace_reg case. */
+       if (TEST_BIT (du->uses[r], du_idx))
+ 	{
+ 	  last_replaced_insn = du_idx;
+ 	  
  	  SET_BIT (du->uses[avail_reg], du_idx);
  	  RESET_BIT (du->uses[r], du_idx);
*************** replace_reg_in_block (du, uid_ruid, def,
*** 580,583 ****
--- 608,632 ----
      }
  
+   /* Add REG_DEAD note for replaced register at last use. */
+ 
+   if (last_replaced_insn)
+     {
+       new_reg = regno_use_in (avail_reg,
+ 			      PATTERN (VARRAY_RTX (*uid_ruid,
+ 						   last_replaced_insn)));
+       if (new_reg
+ 	  && ! find_reg_note (VARRAY_RTX (*uid_ruid, last_replaced_insn),
+ 				      REG_DEAD, new_reg))
+ 	{
+ 	  REG_NOTES (VARRAY_RTX (*uid_ruid, last_replaced_insn))
+ 	    = gen_rtx_EXPR_LIST (REG_DEAD, new_reg,
+ 				 REG_NOTES (VARRAY_RTX (*uid_ruid,
+ 							last_replaced_insn)));
+ 	  remove_note (VARRAY_RTX (*uid_ruid, last_replaced_insn),
+ 		       find_reg_note (VARRAY_RTX (*uid_ruid, last_replaced_insn),
+ 					    REG_DEAD, reg_use));
+ 	}
+     }
+ 
    return status;
  }
*************** rr_replace_reg (x, reg_use, reg_sub, rep
*** 612,616 ****
  	    return reg_sub;
  	  else
! 	    return gen_rtx_REG (GET_MODE (x), REGNO (reg_use));
  	}
  
--- 661,665 ----
  	    return reg_sub;
  	  else
! 	    return gen_rtx_REG (GET_MODE (x), REGNO (reg_sub));
  	}