re PR middle-end/20491 (internal compiler error: in subreg_regno_offset, at rtlanal.c:3042)

	PR middle-end/20491
	* config/ia64/ia64.c (rtx_needs_barrier): Recurse instead of
	falling through from SUBREG case to REG.

From-SVN: r98225

gcc/ChangeLog

+2005-04-16  Joseph S. Myers  <joseph@codesourcery.com>
+
+	PR middle-end/20491
+	* config/ia64/ia64.c (rtx_needs_barrier): Recurse instead of
+	falling through from SUBREG case to REG.
+
 2005-04-15  Roger Sayle  <roger@eyesopen.com>
 
 	* fold-const.c (fold_relational_hi_lo): Delete function and prototype.

gcc/config/ia64/ia64.c

@@ -5196,8 +5196,8 @@ rtx_needs_barrier (rtx x, struct reg_flags flags, int pred)
       break;
 
     case SUBREG:
-      x = SUBREG_REG (x);
-      /* FALLTHRU */
+      need_barrier |= rtx_needs_barrier (SUBREG_REG (x), flags, pred);
+      break;
     case REG:
       if (REGNO (x) == AR_UNAT_REGNUM)
 	{