ira.c (setup_pressure_classes): Handle synonymous classes.

gcc/
	* ira.c (setup_pressure_classes): Handle synonymous classes.

From-SVN: r191159

gcc/ChangeLog

+2012-09-10  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	* ira.c (setup_pressure_classes): Handle synonymous classes.
+
 2012-09-10  Marc Glisse  <marc.glisse@inria.fr>
 
         * tree-ssa-forwprop.c (simplify_bitfield_ref): New function.

gcc/ira.c

@@ -789,7 +789,7 @@ setup_pressure_classes (void)
 	     hard registers and movement between them is costly
 	     (e.g. SPARC FPCC registers).  We still should consider it
 	     as a candidate for a pressure class.  */
-	  && alloc_reg_class_subclasses[cl][0] != LIM_REG_CLASSES)
+	  && alloc_reg_class_subclasses[cl][0] < cl)
 	{
 	  /* Check that the moves between any hard registers of the
 	     current class are not more expensive for a legal mode