Fix from Dave Korn in case a backend does not declare any define_register_constraints

From-SVN: r147020

gcc/ChangeLog

+2009-04-30  Dave Korn  <dave.korn.cygwin@gmail.com>
+
+	* ira.c (setup_cover_and_important_classes):  Use safe macro
+	REG_CLASS_FOR_CONSTRAINT instead of calling regclass_for_constraint
+	directly.
+	* genpreds.c (write_tm_preds_h):  Output suitable definition of
+	REG_CLASS_FOR_CONSTRAINT.
+
 2009-04-30  Rafael Avila de Espindola  <espindola@google.com>
 
 	* alloc-pool.c (alloc_pool_descriptor): Use an insert_opion value

gcc/genpreds.c

@@ -1280,9 +1280,13 @@ write_tm_preds_h (void)
 	puts ("extern enum reg_class regclass_for_constraint "
 	      "(enum constraint_num);\n"
 	      "#define REG_CLASS_FROM_CONSTRAINT(c_,s_) \\\n"
-	      "    regclass_for_constraint (lookup_constraint (s_))\n");
+	      "    regclass_for_constraint (lookup_constraint (s_))\n"
+	      "#define REG_CLASS_FOR_CONSTRAINT(x_) \\\n"
+	      "    regclass_for_constraint (x_)\n");
       else
-	puts ("#define REG_CLASS_FROM_CONSTRAINT(c_,s_) NO_REGS");
+	puts ("#define REG_CLASS_FROM_CONSTRAINT(c_,s_) NO_REGS\n"
+	      "#define REG_CLASS_FOR_CONSTRAINT(x_) \\\n"
+	      "    NO_REGS\n");
       if (have_const_int_constraints)
 	puts ("extern bool insn_const_int_ok_for_constraint "
 	      "(HOST_WIDE_INT, enum constraint_num);\n"

gcc/ira.c

@@ -756,7 +756,7 @@ setup_cover_and_important_classes (void)
 	    continue;
 #ifdef CONSTRAINT_NUM_DEFINED_P
 	  for (j = 0; j < CONSTRAINT__LIMIT; j++)
-	    if ((int) regclass_for_constraint ((enum constraint_num) j) == i)
+	    if ((int) REG_CLASS_FOR_CONSTRAINT ((enum constraint_num) j) == i)
 	      break;
 	  if (j < CONSTRAINT__LIMIT)
 	    {