Re: [PATCH] Don't disallow copyprop for virtual ops for loop depth check

[Andrew Pinski <pinskia at gmail dot com>]

> ChangeLog:
> 
> 	* tree-ssa-dom.c (cprop_operand): Ignore the loop depth when
> 	copyproping on virtual operands.
> 	(propagate_rhs_into_lhs): Likewise.
> 	* tree-ssa-copy.c (copy_prop_visit_phi_node): Likewise.
> 
> 	* gcc.c-torture/compile/pr29922.c: New test.
> 	* gfortran.fortran-torture/compile/pr29922.f: New test.

Lets try that with the patch this time.

-- Pinski

Index: testsuite/gcc.c-torture/compile/pr29922.c
===================================================================
--- testsuite/gcc.c-torture/compile/pr29922.c	(revision 0)
+++ testsuite/gcc.c-torture/compile/pr29922.c	(revision 0)
@@ -0,0 +1,25 @@
+struct menu {
+ struct menu *next;
+ struct menu *list;
+};
+char line[128];
+int conf_choice(struct menu *menu)
+{
+ struct menu *child;
+ while (1)
+ {
+  for (child = menu->list; child; child = child->next)
+ {
+   if (menu_is_visible())
+    break;
+  }
+  if (!child)
+   continue;
+  if (__builtin_strlen(line) == 100)
+ {
+   f();
+   continue;
+  }
+  return 1;
+ }
+}
Index: testsuite/gfortran.fortran-torture/compile/pr29922.f
===================================================================
--- testsuite/gfortran.fortran-torture/compile/pr29922.f	(revision 0)
+++ testsuite/gfortran.fortran-torture/compile/pr29922.f	(revision 0)
@@ -0,0 +1,14 @@
+C     This test used to ICE in PRE because of VOPs with one argument.
+      REAL               Q( 2, 2 )
+                        DO 90 IM3 = 1, 3
+                           DO 10 J1 = 1, 2
+                             RES = Q( J1, 1 )*CS + Q( J1, 2 )*SN
+                             Q( J1, 2 ) =-Q( J1, 1 ) + Q( J1, 2 )*CS
+   10                        CONTINUE
+                        RES = RES +  Q( 2, 2 )  / EPS
+                              IF( RES.GT.RMAX ) THEN
+                                 RMAX = RES
+                              END IF
+   90                   CONTINUE
+      END
+
Index: tree-ssa-dom.c
===================================================================
--- tree-ssa-dom.c	(revision 119245)
+++ tree-ssa-dom.c	(working copy)
@@ -1700,8 +1700,10 @@
 	 depth than the propagatee.  Otherwise, this may move loop variant
 	 variables outside of their loops and prevent coalescing
 	 opportunities.  If the value was loop invariant, it will be hoisted
-	 by LICM and exposed for copy propagation.  */
-      if (loop_depth_of_name (val) > loop_depth_of_name (op))
+	 by LICM and exposed for copy propagation.  We don't care much about
+         virtual operands.  */
+      if (loop_depth_of_name (val) > loop_depth_of_name (op)
+	  && is_gimple_reg (val))
 	return false;
 
       /* Dump details.  */
@@ -2136,12 +2138,13 @@
 propagate_rhs_into_lhs (tree stmt, tree lhs, tree rhs, bitmap interesting_names)
 {
   /* First verify that propagation is valid and isn't going to move a
-     loop variant variable outside its loop.  */
+     loop variant variable outside its loop except for vops.  */
   if (! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)
       && (TREE_CODE (rhs) != SSA_NAME
 	  || ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs))
       && may_propagate_copy (lhs, rhs)
-      && loop_depth_of_name (lhs) >= loop_depth_of_name (rhs))
+      && (loop_depth_of_name (lhs) > loop_depth_of_name (rhs)
+	  || !is_gimple_reg (lhs)))
     {
       use_operand_p use_p;
       imm_use_iterator iter;
Index: tree-ssa-copy.c
===================================================================
--- tree-ssa-copy.c	(revision 119245)
+++ tree-ssa-copy.c	(working copy)
@@ -801,8 +801,11 @@
 	 Otherwise, this may move loop variant variables outside of
 	 their loops and prevent coalescing opportunities.  If the
 	 value was loop invariant, it will be hoisted by LICM and
-	 exposed for copy propagation.  */
-      if (loop_depth_of_name (arg) > loop_depth_of_name (lhs))
+	 exposed for copy propagation.  We don't care much about
+	 virtual operands as they don't get coalesced during out-
+	 of-ssa.  */
+      if (loop_depth_of_name (arg) > loop_depth_of_name (lhs)
+	  && is_gimple_reg (arg))
 	{
 	  phi_val.value = lhs;
 	  break;