combine.c (can_combine_p): Allow ZERO_EXTRACT and STRICT_LOW_PART.

2003-03-31  Eric Christopher  <echristo@redhat.com>

	* combine.c (can_combine_p): Allow ZERO_EXTRACT and STRICT_LOW_PART.
	(combinable_i3pat): Remove call to expand_field_assignment and
	#if 0'd code.

From-SVN: r65118

gcc/ChangeLog

+2003-03-31  Eric Christopher  <echristo@redhat.com>
+
+	* combine.c (can_combine_p): Allow ZERO_EXTRACT and STRICT_LOW_PART.
+	(combinable_i3pat): Remove call to expand_field_assignment and
+	#if 0'd code.
+
 2003-03-31  Mark Mitchell  <mark@codesourcery.com>
 
 	PR c++/10278
@@ -9596,4 +9602,3 @@ Mon Mar 24 20:03:03 CET 2003  Jan Hubicka  <jh@suse.cz>
 	* doc/tm.texi (REGISTER_TARGET_PRAGMAS): Update
 
 See ChangeLog.8 for earlier changes.
-

gcc/combine.c

@@ -1065,8 +1065,6 @@ can_combine_p (insn, i3, pred, succ, pdest, psrc)
 
   /* Don't eliminate a store in the stack pointer.  */
   if (dest == stack_pointer_rtx
-      /* If we couldn't eliminate a field assignment, we can't combine.  */
-      || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == STRICT_LOW_PART
       /* Don't combine with an insn that sets a register to itself if it has
 	 a REG_EQUAL note.  This may be part of a REG_NO_CONFLICT sequence.  */
       || (rtx_equal_p (src, dest) && find_reg_note (insn, REG_EQUAL, NULL_RTX))
@@ -1319,46 +1317,16 @@ combinable_i3pat (i3, loc, i2dest, i1dest, i1_not_in_src, pi3dest_killed)
 
   if (GET_CODE (x) == SET)
     {
-      rtx set = expand_field_assignment (x);
+      rtx set = x ;
       rtx dest = SET_DEST (set);
       rtx src = SET_SRC (set);
       rtx inner_dest = dest;
 
-#if 0
-      rtx inner_src = src;
-#endif
-
-      SUBST (*loc, set);
-
       while (GET_CODE (inner_dest) == STRICT_LOW_PART
 	     || GET_CODE (inner_dest) == SUBREG
 	     || GET_CODE (inner_dest) == ZERO_EXTRACT)
 	inner_dest = XEXP (inner_dest, 0);
 
-  /* We probably don't need this any more now that LIMIT_RELOAD_CLASS
-     was added.  */
-#if 0
-      while (GET_CODE (inner_src) == STRICT_LOW_PART
-	     || GET_CODE (inner_src) == SUBREG
-	     || GET_CODE (inner_src) == ZERO_EXTRACT)
-	inner_src = XEXP (inner_src, 0);
-
-      /* If it is better that two different modes keep two different pseudos,
-	 avoid combining them.  This avoids producing the following pattern
-	 on a 386:
-	  (set (subreg:SI (reg/v:QI 21) 0)
-	       (lshiftrt:SI (reg/v:SI 20)
-	           (const_int 24)))
-	 If that were made, reload could not handle the pair of
-	 reg 20/21, since it would try to get any GENERAL_REGS
-	 but some of them don't handle QImode.  */
-
-      if (rtx_equal_p (inner_src, i2dest)
-	  && GET_CODE (inner_dest) == REG
-	  && ! MODES_TIEABLE_P (GET_MODE (i2dest), GET_MODE (inner_dest)))
-	return 0;
-#endif
-
       /* Check for the case where I3 modifies its output, as
 	 discussed above.  */
       if ((inner_dest != dest