ira-int.h (target_ira_int): Add x_ira_useful_class_mode_regs.

gcc/
	* ira-int.h (target_ira_int): Add x_ira_useful_class_mode_regs.
	(ira_useful_class_mode_regs): New macro.
	* ira.c (clarify_prohibited_class_mode_regs): Set up
	ira_useful_class_mode_regs.
	* ira-color.c (setup_profitable_hard_regs): Use it to initialise
	profitable_hard_regs.

From-SVN: r191996

gcc/ChangeLog

 2012-10-02  Richard Sandiford  <rdsandiford@googlemail.com>
 
+	* ira-int.h (target_ira_int): Add x_ira_useful_class_mode_regs.
+	(ira_useful_class_mode_regs): New macro.
+	* ira.c (clarify_prohibited_class_mode_regs): Set up
+	ira_useful_class_mode_regs.
+	* ira-color.c (setup_profitable_hard_regs): Use it to initialise
+	profitable_hard_regs.
+
+2012-10-02  Richard Sandiford  <rdsandiford@googlemail.com>
+
 	* ira.h (target_ira): Add x_ira_class_singleton.
 	(ira_class_singleton): New macro.
 	* ira.c (setup_prohibited_class_mode_regs): Set up ira_class_singleton.

gcc/ira-color.c

@@ -1023,10 +1023,9 @@ setup_profitable_hard_regs (void)
 	CLEAR_HARD_REG_SET (data->profitable_hard_regs);
       else
 	{
+	  mode = ALLOCNO_MODE (a);
 	  COPY_HARD_REG_SET (data->profitable_hard_regs,
-			     reg_class_contents[aclass]);
-	  AND_COMPL_HARD_REG_SET (data->profitable_hard_regs,
-				  ira_no_alloc_regs);
+			     ira_useful_class_mode_regs[aclass][mode]);
 	  nobj = ALLOCNO_NUM_OBJECTS (a);
 	  for (k = 0; k < nobj; k++)
 	    {

gcc/ira-int.h

@@ -816,6 +816,20 @@ struct target_ira_int {
      values for given mode are zero.  */
   HARD_REG_SET x_ira_prohibited_class_mode_regs[N_REG_CLASSES][NUM_MACHINE_MODES];
 
+  /* Index [CL][M] contains R if R appears somewhere in a register of the form:
+
+         (reg:M R'), R' not in x_ira_prohibited_class_mode_regs[CL][M]
+
+     For example, if:
+
+     - (reg:M 2) is valid and occupies two registers;
+     - register 2 belongs to CL; and
+     - register 3 belongs to the same pressure class as CL
+
+     then (reg:M 2) contributes to [CL][M] and registers 2 and 3 will be
+     in the set.  */
+  HARD_REG_SET x_ira_useful_class_mode_regs[N_REG_CLASSES][NUM_MACHINE_MODES];
+
   /* The value is number of elements in the subsequent array.  */
   int x_ira_important_classes_num;
 
@@ -902,6 +916,8 @@ extern struct target_ira_int *this_target_ira_int;
   (this_target_ira_int->x_ira_class_hard_reg_index)
 #define ira_prohibited_class_mode_regs \
   (this_target_ira_int->x_ira_prohibited_class_mode_regs)
+#define ira_useful_class_mode_regs \
+  (this_target_ira_int->x_ira_useful_class_mode_regs)
 #define ira_important_classes_num \
   (this_target_ira_int->x_ira_important_classes_num)
 #define ira_important_classes \

gcc/ira.c

@@ -1495,6 +1495,8 @@ clarify_prohibited_class_mode_regs (void)
 
   for (cl = (int) N_REG_CLASSES - 1; cl >= 0; cl--)
     for (j = 0; j < NUM_MACHINE_MODES; j++)
+      {
+	CLEAR_HARD_REG_SET (ira_useful_class_mode_regs[cl][j]);
 	for (k = ira_class_hard_regs_num[cl] - 1; k >= 0; k--)
 	  {
 	    hard_regno = ira_class_hard_regs[cl][k];
@@ -1517,6 +1519,11 @@ clarify_prohibited_class_mode_regs (void)
 				    hard_regno);
 		  break;
 		}
+	    if (!TEST_HARD_REG_BIT (ira_prohibited_class_mode_regs[cl][j],
+				    hard_regno))
+	      add_to_hard_reg_set (&ira_useful_class_mode_regs[cl][j],
+				   (enum machine_mode) j, hard_regno);
+	  }
       }
 }