regclass.c (record_reg_classes, case 'p'): Set classes appropriately.

        * regclass.c (record_reg_classes, case 'p'): Set classes appropriately.
        An alternative always fails if it needs a pseudo and no suitable
        register class can be found.
Bootstrapped on solaris.

From-SVN: r25402

gcc/ChangeLog

+Wed Feb 24 14:03:54 1999  Jeffrey A Law  (law@cygnus.com)
+
+	* regclass.c (record_reg_classes, case 'p'): Set classes appropriately.
+	An alternative always fails if it needs a pseudo and no suitable
+	register class can be found.
+
 Wed Feb 24 19:47:56 1999  J"orn Rennecke <amylaar@cygnus.co.uk>
 
 	* loop.h (loop_insn_first_p): Declare.

gcc/regclass.c

@@ -1268,6 +1268,12 @@ record_reg_classes (n_alts, n_ops, ops, modes, constraints, insn)
 	      case 'p':
 		allows_addr = 1;
 		win = address_operand (op, GET_MODE (op));
+		/* We know this operand is an address, so we want it to be
+		   allocated to a register that can be the base of an
+		   address, ie BASE_REG_CLASS.  */
+		classes[i]
+		  = reg_class_subunion[(int) classes[i]]
+		    [(int) BASE_REG_CLASS];
 		break;
 
 	      case 'm':  case 'o':  case 'V':
@@ -1399,7 +1405,12 @@ record_reg_classes (n_alts, n_ops, ops, modes, constraints, insn)
 	    {
 	      if (classes[i] == NO_REGS)
 		{
-		  if (! allows_addr)
+		    /* We must always fail if the operand is a REG, but
+		       we did not find a suitable class.
+
+		       Otherwise we may perform an uninitialized read
+		       from this_op_costs after the `continue' statement
+		       below.  */
 		    alt_fail = 1;
 		}
 	      else