rs6000.md (extzvsi_internal2): Revert most of 2002-07-26 change.

	* config/rs6000/rs6000.md (extzvsi_internal2): Revert most of
	2002-07-26 change.  Comment.

From-SVN: r56867

gcc/ChangeLog

+2002-09-06  Alan Modra  <amodra@bigpond.net.au>
+
+	* config/rs6000/rs6000.md (extzvsi_internal2): Revert most of
+	2002-07-26 change.  Comment.
+
 2002-09-05  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* frv.c (frv_unique_section, frv_select_section,

gcc/config/rs6000/rs6000.md

@@ -3880,14 +3880,12 @@
   if (which_alternative == 1)
      return \"#\";
 
-  if ((start > 0 && start + size <= 16) || start >= 16)
+  /* Since we are using the output value, we can't ignore any need for
+     a shift.  The bitfield must end at the LSB.  */
+  if (start >= 16 && start + size == 32)
     {
-      operands[3] = GEN_INT (((1 << (16 - (start & 15)))
-			      - (1 << (16 - (start & 15) - size))));
-      if (start < 16)
-	return \"{andiu.|andis.} %0,%1,%3\";
-      else
-	return \"{andil.|andi.} %0,%1,%3\";
+      operands[3] = GEN_INT ((1 << size) - 1);
+      return \"{andil.|andi.} %0,%1,%3\";
     }
 
   if (start + size >= 32)