loop.c (check_final_value): Use v->always_executed instead of v->always_computable.

	* loop.c (check_final_value): Use v->always_executed
	instead of v->always_computable.
	* unroll.c (final_giv_value): Don't calculate the final
	value as a function of the biv if the giv is not computed
	for every loop iteration.

From-SVN: r54634

gcc/ChangeLog

 2002-06-14  Eric Botcazou  <ebotcazou@multimania.com>
+
+	* loop.c (check_final_value): Use v->always_executed
+	instead of v->always_computable.
+	* unroll.c (final_giv_value): Don't calculate the final
+	value as a function of the biv if the giv is not computed
+	for every loop iteration.
+
+2002-06-14  Eric Botcazou  <ebotcazou@multimania.com>
  
 	* loop.c (for_each_insn_in_loop): Fix formatting and comments.
 

gcc/loop.c

@@ -5943,7 +5943,8 @@ check_final_value (loop, v)
 #endif
 
   if ((final_value = final_giv_value (loop, v))
-      && (v->always_computable || last_use_this_basic_block (v->dest_reg, v->insn)))
+      && (v->always_executed
+	  || last_use_this_basic_block (v->dest_reg, v->insn)))
     {
       int biv_increment_seen = 0, before_giv_insn = 0;
       rtx p = v->insn;

gcc/unroll.c

@@ -3249,7 +3249,8 @@ final_giv_value (loop, v)
 
   /* Try to calculate the final value as a function of the biv it depends
      upon.  The only exit from the loop must be the fall through at the bottom
-     (otherwise it may not have its final value when the loop exits).  */
+     and the insn that sets the giv must be executed on every iteration
+     (otherwise the giv may not have its final value when the loop exits).  */
 
   /* ??? Can calculate the final giv value by subtracting off the
      extra biv increments times the giv's mult_val.  The loop must have
@@ -3257,7 +3258,8 @@ final_giv_value (loop, v)
      to be known.  */
 
   if (n_iterations != 0
-      && ! loop->exit_count)
+      && ! loop->exit_count
+      && v->always_executed)
     {
       /* ?? It is tempting to use the biv's value here since these insns will
 	 be put after the loop, and hence the biv will have its final value