[1/2] tree-ssa-strlen optimization pass

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

Here is an updated version of the support patch for the tree-ssa-strlen.c
optimization.  The only change is the propagation of gimple_block
to the new call from the old call, otherwise Wobjsize-1.c testcase
fails when we optimize that __strcpy_chk into __memcpy_chk, but don't
propagate its BLOCK.  Perhaps gimplify_and_update_call_from_tree and
update_call_from_tree should do it as well, for all the statements without
gimple_block it creates (can do that as a follow-up).

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2011-09-15  Jakub Jelinek  <jakub@redhat.com>

	* gimple-fold.c (gimplify_and_update_call_from_tree): Set
	gctx.into_ssa after push_gimplify_context.

	* gimple.c (gimple_build_call_valist): New function.
	* gimple.h (gimple_build_call_valist): New prototype.
	* tree-ssa-propagate.c (finish_update_gimple_call): New function.
	(update_gimple_call): Likewise.
	(update_call_from_tree): Use finish_update_gimple_call.
	* tree-ssa-propagate.h (update_gimple_call): New prototype.

--- gcc/gimple-fold.c.jj	2011-09-15 12:18:54.000000000 +0200
+++ gcc/gimple-fold.c	2011-09-15 12:23:58.000000000 +0200
@@ -551,6 +551,7 @@ gimplify_and_update_call_from_tree (gimp
   reaching_vuse = gimple_vuse (stmt);
 
   push_gimplify_context (&gctx);
+  gctx.into_ssa = gimple_in_ssa_p (cfun);
 
   if (lhs == NULL_TREE)
     {
--- gcc/gimple.c.jj	2011-09-15 12:18:37.000000000 +0200
+++ gcc/gimple.c	2011-09-15 12:23:58.000000000 +0200
@@ -215,9 +215,10 @@ gimple_call_reset_alias_info (gimple s)
     pt_solution_reset (gimple_call_clobber_set (s));
 }
 
-/* Helper for gimple_build_call, gimple_build_call_vec and
-   gimple_build_call_from_tree.  Build the basic components of a
-   GIMPLE_CALL statement to function FN with NARGS arguments.  */
+/* Helper for gimple_build_call, gimple_build_call_valist,
+   gimple_build_call_vec and gimple_build_call_from_tree.  Build the basic
+   components of a GIMPLE_CALL statement to function FN with NARGS
+   arguments.  */
 
 static inline gimple
 gimple_build_call_1 (tree fn, unsigned nargs)
@@ -272,6 +273,26 @@ gimple_build_call (tree fn, unsigned nar
 }
 
 
+/* Build a GIMPLE_CALL statement to function FN.  NARGS is the number of
+   arguments.  AP contains the arguments.  */
+
+gimple
+gimple_build_call_valist (tree fn, unsigned nargs, va_list ap)
+{
+  gimple call;
+  unsigned i;
+
+  gcc_assert (TREE_CODE (fn) == FUNCTION_DECL || is_gimple_call_addr (fn));
+
+  call = gimple_build_call_1 (fn, nargs);
+
+  for (i = 0; i < nargs; i++)
+    gimple_call_set_arg (call, i, va_arg (ap, tree));
+
+  return call;
+}
+
+
 /* Helper for gimple_build_call_internal and gimple_build_call_internal_vec.
    Build the basic components of a GIMPLE_CALL statement to internal
    function FN with NARGS arguments.  */
--- gcc/gimple.h.jj	2011-09-15 12:18:54.000000000 +0200
+++ gcc/gimple.h	2011-09-15 12:23:58.000000000 +0200
@@ -831,6 +831,7 @@ gimple gimple_build_debug_source_bind_st
 
 gimple gimple_build_call_vec (tree, VEC(tree, heap) *);
 gimple gimple_build_call (tree, unsigned, ...);
+gimple gimple_build_call_valist (tree, unsigned, va_list);
 gimple gimple_build_call_internal (enum internal_fn, unsigned, ...);
 gimple gimple_build_call_internal_vec (enum internal_fn, VEC(tree, heap) *);
 gimple gimple_build_call_from_tree (tree);
--- gcc/tree-ssa-propagate.c.jj	2011-09-15 12:18:37.000000000 +0200
+++ gcc/tree-ssa-propagate.c	2011-09-15 16:46:54.000000000 +0200
@@ -1,5 +1,5 @@
 /* Generic SSA value propagation engine.
-   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
    Contributed by Diego Novillo <dnovillo@redhat.com>
 
@@ -673,6 +673,40 @@ move_ssa_defining_stmt_for_defs (gimple 
     }
 }
 
+/* Helper function for update_gimple_call and update_call_from_tree.
+   A GIMPLE_CALL STMT is being replaced with GIMPLE_CALL NEW_STMT.  */
+
+static void
+finish_update_gimple_call (gimple_stmt_iterator *si_p, gimple new_stmt,
+			   gimple stmt)
+{
+  gimple_call_set_lhs (new_stmt, gimple_call_lhs (stmt));
+  move_ssa_defining_stmt_for_defs (new_stmt, stmt);
+  gimple_set_vuse (new_stmt, gimple_vuse (stmt));
+  gimple_set_vdef (new_stmt, gimple_vdef (stmt));
+  gimple_set_location (new_stmt, gimple_location (stmt));
+  if (gimple_block (new_stmt) == NULL_TREE)
+    gimple_set_block (new_stmt, gimple_block (stmt));
+  gsi_replace (si_p, new_stmt, false);
+}
+
+/* Update a GIMPLE_CALL statement at iterator *SI_P to call to FN
+   with number of arguments NARGS, where the arguments in GIMPLE form
+   follow NARGS argument.  */
+
+bool
+update_gimple_call (gimple_stmt_iterator *si_p, tree fn, int nargs, ...)
+{
+  va_list ap;
+  gimple new_stmt, stmt = gsi_stmt (*si_p);
+
+  gcc_assert (is_gimple_call (stmt));
+  va_start (ap, nargs);
+  new_stmt = gimple_build_call_valist (fn, nargs, ap);
+  finish_update_gimple_call (si_p, new_stmt, stmt);
+  va_end (ap);
+  return true;
+}
 
 /* Update a GIMPLE_CALL statement at iterator *SI_P to reflect the
    value of EXPR, which is expected to be the result of folding the
@@ -689,14 +723,8 @@ move_ssa_defining_stmt_for_defs (gimple 
 bool
 update_call_from_tree (gimple_stmt_iterator *si_p, tree expr)
 {
-  tree lhs;
-
   gimple stmt = gsi_stmt (*si_p);
 
-  gcc_assert (is_gimple_call (stmt));
-
-  lhs = gimple_call_lhs (stmt);
-
   if (valid_gimple_call_p (expr))
     {
       /* The call has simplified to another call.  */
@@ -716,18 +744,14 @@ update_call_from_tree (gimple_stmt_itera
         }
 
       new_stmt = gimple_build_call_vec (fn, args);
-      gimple_call_set_lhs (new_stmt, lhs);
-      move_ssa_defining_stmt_for_defs (new_stmt, stmt);
-      gimple_set_vuse (new_stmt, gimple_vuse (stmt));
-      gimple_set_vdef (new_stmt, gimple_vdef (stmt));
-      gimple_set_location (new_stmt, gimple_location (stmt));
-      gsi_replace (si_p, new_stmt, false);
+      finish_update_gimple_call (si_p, new_stmt, stmt);
       VEC_free (tree, heap, args);
 
       return true;
     }
   else if (valid_gimple_rhs_p (expr))
     {
+      tree lhs = gimple_call_lhs (stmt);
       gimple new_stmt;
 
       /* The call has simplified to an expression
--- gcc/tree-ssa-propagate.h.jj	2011-09-15 12:18:37.000000000 +0200
+++ gcc/tree-ssa-propagate.h	2011-09-15 12:23:58.000000000 +0200
@@ -1,6 +1,7 @@
 /* Data structures and function declarations for the SSA value propagation
    engine.
-   Copyright (C) 2004, 2005, 2007, 2008, 2010 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2007, 2008, 2010, 2011
+   Free Software Foundation, Inc.
    Contributed by Diego Novillo <dnovillo@redhat.com>
 
 This file is part of GCC.
@@ -72,6 +73,7 @@ typedef tree (*ssa_prop_get_value_fn) (t
 void ssa_propagate (ssa_prop_visit_stmt_fn, ssa_prop_visit_phi_fn);
 bool valid_gimple_rhs_p (tree);
 void move_ssa_defining_stmt_for_defs (gimple, gimple);
+bool update_gimple_call (gimple_stmt_iterator *, tree, int, ...);
 bool update_call_from_tree (gimple_stmt_iterator *, tree);
 bool stmt_makes_single_store (gimple);
 bool substitute_and_fold (ssa_prop_get_value_fn, ssa_prop_fold_stmt_fn, bool);

	Jakub