2009-09-03 Basile Starynkevitch <basile@starynkevitch.net>

	MELT branch merged with trunk rev 151367



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/melt-branch@151369 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 44 insertions, 13 deletions

diff --git a/gcc/reload.c b/gcc/reload.c
index 257acd0a509..1435945d62c 100644
--- a/gcc/reload.c
+++ b/gcc/reload.c
@@ -112,6 +112,7 @@ a register with any other reload.  */
 #include "params.h"
 #include "target.h"
 #include "df.h"
+#include "ira.h"
 
 /* True if X is a constant that can be forced into the constant pool.  */
 #define CONST_POOL_OK_P(X)			\
@@ -2589,6 +2590,7 @@ find_reloads (rtx insn, int replace, int ind_levels, int live_known,
   char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
   int goal_alternative_swapped;
   int best;
+  int best_small_class_operands_num;
   int commutative;
   char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
   rtx substed_operand[MAX_RECOG_OPERANDS];
@@ -2914,6 +2916,7 @@ find_reloads (rtx insn, int replace, int ind_levels, int live_known,
      all the operands together against the register constraints.  */
 
   best = MAX_RECOG_OPERANDS * 2 + 600;
+  best_small_class_operands_num = 0;
 
   swapped = 0;
   goal_alternative_swapped = 0;
@@ -3697,22 +3700,48 @@ find_reloads (rtx insn, int replace, int ind_levels, int live_known,
       /* If this alternative can be made to work by reloading,
 	 and it needs less reloading than the others checked so far,
 	 record it as the chosen goal for reloading.  */
-      if (! bad && best > losers)
+      if (! bad)
 	{
-	  for (i = 0; i < noperands; i++)
+	  bool change_p = false;
+	  int small_class_operands_num = 0;
+
+	  if (best >= losers)
 	    {
-	      goal_alternative[i] = this_alternative[i];
-	      goal_alternative_win[i] = this_alternative_win[i];
-	      goal_alternative_match_win[i] = this_alternative_match_win[i];
-	      goal_alternative_offmemok[i] = this_alternative_offmemok[i];
-	      goal_alternative_matches[i] = this_alternative_matches[i];
-	      goal_alternative_earlyclobber[i]
-		= this_alternative_earlyclobber[i];
+	      for (i = 0; i < noperands; i++)
+		small_class_operands_num
+		  += SMALL_REGISTER_CLASS_P (this_alternative[i]) ? 1 : 0;
+	      if (best > losers
+		  || (best == losers
+		      /* If the cost of the reloads is the same,
+			 prefer alternative which requires minimal
+			 number of small register classes for the
+			 operands.  This improves chances of reloads
+			 for insn requiring small register
+			 classes.  */
+		      && (small_class_operands_num
+			  < best_small_class_operands_num)))
+		change_p = true;
+	    }
+	  if (change_p)
+	    {
+	      for (i = 0; i < noperands; i++)
+		{
+		  goal_alternative[i] = this_alternative[i];
+		  goal_alternative_win[i] = this_alternative_win[i];
+		  goal_alternative_match_win[i]
+		    = this_alternative_match_win[i];
+		  goal_alternative_offmemok[i]
+		    = this_alternative_offmemok[i];
+		  goal_alternative_matches[i] = this_alternative_matches[i];
+		  goal_alternative_earlyclobber[i]
+		    = this_alternative_earlyclobber[i];
+		}
+	      goal_alternative_swapped = swapped;
+	      best = losers;
+	      best_small_class_operands_num = small_class_operands_num;
+	      goal_alternative_number = this_alternative_number;
+	      goal_earlyclobber = this_earlyclobber;
 	    }
-	  goal_alternative_swapped = swapped;
-	  best = losers;
-	  goal_alternative_number = this_alternative_number;
-	  goal_earlyclobber = this_earlyclobber;
 	}
     }
 
@@ -6736,6 +6765,8 @@ find_equiv_reg (rtx goal, rtx insn, enum reg_class rclass, int other,
   while (1)
     {
       p = PREV_INSN (p);
+      if (p && DEBUG_INSN_P (p))
+	continue;
       num++;
       if (p == 0 || LABEL_P (p)
 	  || num > PARAM_VALUE (PARAM_MAX_RELOAD_SEARCH_INSNS))