re PR rtl-optimization/8705 ([HP-PA] ICE in emit_move_insn_1, at expr.c:3101)

	PR opt/8705
	* gcse.c (try_replace_reg): On a successful substitution of a constant
	into a single set, try to simplify the source of the set.
	* loop.c (scan_loop): Don't try to optimize a MODE_CC set with a
	constant source.

From-SVN: r66060

gcc/ChangeLog

+2003-04-24  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
+
+	PR opt/8705
+	* gcse.c (try_replace_reg): On a successful substitution of a constant
+	into a single set, try to simplify the source of the set.
+	* loop.c (scan_loop): Don't try to optimize a MODE_CC set with a
+	constant source.
+
 2003-04-24  Neil Booth  <neil@daikokuya.co.uk>
 
 	* cpplex.c (cpp_token_len): Tighten up.

gcc/gcse.c

@@ -3963,6 +3963,15 @@ try_replace_reg (from, to, insn)
   if (num_changes_pending () && apply_change_group ())
     success = 1;
 
+  /* Try to simplify SET_SRC if we have substituted a constant.  */
+  if (success && set && CONSTANT_P (to))
+    {
+      src = simplify_rtx (SET_SRC (set));
+
+      if (src)
+	validate_change (insn, &SET_SRC (set), src, 0);
+    }
+
   if (!success && set && reg_mentioned_p (from, SET_SRC (set)))
     {
       /* If above failed and this is a single set, try to simplify the source of

gcc/loop.c

@@ -833,11 +833,17 @@ scan_loop (loop, flags)
 		   That behavior is incorrect and was removed.  */
 		insert_temp = 1;
 
+	      /* Don't try to optimize a MODE_CC set with a constant
+		 source.  It probably will be combined with a conditional
+		 jump.  */
+	      if (GET_MODE_CLASS (GET_MODE (SET_DEST (set))) == MODE_CC
+		  && CONSTANT_P (src))
+		;
 	      /* Don't try to optimize a register that was made
 		 by loop-optimization for an inner loop.
 		 We don't know its life-span, so we can't compute
 		 the benefit.  */
-	      if (REGNO (SET_DEST (set)) >= max_reg_before_loop)
+	      else if (REGNO (SET_DEST (set)) >= max_reg_before_loop)
 		;
 	      /* Don't move the source and add a reg-to-reg copy:
 		 - with -Os (this certainly increases size),