re PR rtl-optimization/18420 (ICE compiling mesa at -O2)

	PR rtl-optimization/18420
	* simplify-rtx.c (simplify_gen_subreg): Revert 2004-10-28 change.

From-SVN: r91419

gcc/ChangeLog

+2004-11-28  Ulrich Weigand  <uweigand@de.ibm.com>
+
+	PR rtl-optimization/18420
+	* simplify-rtx.c (simplify_gen_subreg): Revert 2004-10-28 change.
+
 2004-11-28  Steven Bosscher  <stevenb@suse.de>
 	    John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
 

gcc/simplify-rtx.c

@@ -3782,8 +3782,7 @@ simplify_gen_subreg (enum machine_mode outermode, rtx op,
   if (newx)
     return newx;
 
-  if (GET_CODE (op) == SUBREG || GET_MODE (op) == VOIDmode
-      || (REG_P (op) && REGNO (op) < FIRST_PSEUDO_REGISTER))
+  if (GET_CODE (op) == SUBREG || GET_MODE (op) == VOIDmode)
     return NULL_RTX;
 
   if (validate_subreg (outermode, innermode, op, byte))