ifcvt conditional execution and rtx_cost

[David Edelsohn]

>>>>> Roger Sayle writes:

Roger> Any chance that I could ask you to draw up a patch based upon my
Roger> suggestions above?

Hows the following?

David


	* ifcvt.c (total_bb_rtx_cost): New function.
	(find_if_case_1): Compare rtx_cost of basic block to cost of
	BRANCH_COST insns.
	(find_if_case_2): Same.

Index: ifcvt.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/ifcvt.c,v
retrieving revision 1.154
diff -c -p -r1.154 ifcvt.c
*** ifcvt.c	6 Jul 2004 21:50:47 -0000	1.154
--- ifcvt.c	7 Jul 2004 20:09:00 -0000
*************** static bool life_data_ok;
*** 86,91 ****
--- 86,92 ----
  
  /* Forward references.  */
  static int count_bb_insns (basic_block);
+ static int total_bb_rtx_cost (basic_block);
  static rtx first_active_insn (basic_block);
  static rtx last_active_insn (basic_block, int);
  static basic_block block_fallthru (basic_block);
*************** count_bb_insns (basic_block bb)
*** 160,165 ****
--- 161,187 ----
    return count;
  }
  
+ /* Count the total rtx_cost of non-jump active insns in BB.  */
+ 
+ static int
+ total_bb_rtx_insns (basic_block bb)
+ {
+   int count = 0;
+   rtx insn = BB_HEAD (bb);
+ 
+   while (1)
+     {
+       if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == INSN)
+ 	count += rtx_cost (PATTERN (insn), 0);
+ 
+       if (insn == BB_END (bb))
+ 	break;
+       insn = NEXT_INSN (insn);
+     }
+ 
+   return count;
+ }
+ 
  /* Return the first non-jump active insn in the basic block.  */
  
  static rtx
*************** find_if_case_1 (basic_block test_bb, edg
*** 2883,2889 ****
  	     test_bb->index, then_bb->index);
  
    /* THEN is small.  */
!   if (count_bb_insns (then_bb) > BRANCH_COST)
      return FALSE;
  
    /* Registers set are dead, or are predicable.  */
--- 2905,2911 ----
  	     test_bb->index, then_bb->index);
  
    /* THEN is small.  */
!   if (total_bb_rtx_insns (then_bb) >= COSTS_N_INSNS (BRANCH_COST))
      return FALSE;
  
    /* Registers set are dead, or are predicable.  */
*************** find_if_case_2 (basic_block test_bb, edg
*** 2974,2980 ****
  	     test_bb->index, else_bb->index);
  
    /* ELSE is small.  */
!   if (count_bb_insns (else_bb) > BRANCH_COST)
      return FALSE;
  
    /* Registers set are dead, or are predicable.  */
--- 2996,3002 ----
  	     test_bb->index, else_bb->index);
  
    /* ELSE is small.  */
!   if (total_bb_rtx_insns (else_bb) >= COSTS_N_INSNS (BRANCH_COST))
      return FALSE;
  
    /* Registers set are dead, or are predicable.  */