re PR tree-optimization/58404 (&noninvariant_address not forwproped into ->handled_component)

2013-09-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/58404
	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Also
	propagate non-invariant addresses into dereferences wrapped
	in component references.

	* g++.dg/tree-ssa/pr58404.C: New testcase.

From-SVN: r202525

4 files changed, 58 insertions, 20 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ec525e5..7a0d375 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,12 @@
 2013-09-12  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/58404
+	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Also
+	propagate non-invariant addresses into dereferences wrapped
+	in component references.
+
+2013-09-12  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/58402
 	* passes.def: Move pass_late_warn_uninitialized later.
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 576d56d..75110d9 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-09-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58404
+	* g++.dg/tree-ssa/pr58404.C: New testcase.
+
 2013-09-12  Martin Jambor  <mjambor@suse.cz>
 
 	PR ipa/58371
diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr58404.C b/gcc/testsuite/g++.dg/tree-ssa/pr58404.C
new file mode 100644
index 0000000..aa8fb79
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr58404.C
@@ -0,0 +1,20 @@
+// { dg-do compile }
+// { dg-options "-O -fdump-tree-cddce1" }
+
+struct S { int s; };
+S a[1024];
+
+void
+foo ()
+{
+  for (int i = 0; i < 1024; i++)
+    {
+      S &r = a[i];
+      r.s++;
+    }
+}
+
+// We should propagate the reference into both memory accesses
+// during the first forwprop pass
+// { dg-final { scan-tree-dump-times "= &a" 0 "cddce1" } }
+// { dg-final { cleanup-tree-dump "cddce1" } }
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index 977aebd..f1a4077 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -786,9 +786,10 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
 
   /* Now strip away any outer COMPONENT_REF/ARRAY_REF nodes from the LHS.
      ADDR_EXPR will not appear on the LHS.  */
-  lhs = gimple_assign_lhs (use_stmt);
-  while (handled_component_p (lhs))
-    lhs = TREE_OPERAND (lhs, 0);
+  tree *lhsp = gimple_assign_lhs_ptr (use_stmt);
+  while (handled_component_p (*lhsp))
+    lhsp = &TREE_OPERAND (*lhsp, 0);
+  lhs = *lhsp;
 
   /* Now see if the LHS node is a MEM_REF using NAME.  If so,
      propagate the ADDR_EXPR into the use of NAME and fold the result.  */
@@ -822,11 +823,13 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
       /* If the LHS is a plain dereference and the value type is the same as
          that of the pointed-to type of the address we can put the
 	 dereferenced address on the LHS preserving the original alias-type.  */
-      else if (gimple_assign_lhs (use_stmt) == lhs
-	       && integer_zerop (TREE_OPERAND (lhs, 1))
-	       && useless_type_conversion_p
-	            (TREE_TYPE (TREE_OPERAND (def_rhs, 0)),
-		     TREE_TYPE (gimple_assign_rhs1 (use_stmt)))
+      else if (integer_zerop (TREE_OPERAND (lhs, 1))
+	       && ((gimple_assign_lhs (use_stmt) == lhs
+		    && useless_type_conversion_p
+		         (TREE_TYPE (TREE_OPERAND (def_rhs, 0)),
+		          TREE_TYPE (gimple_assign_rhs1 (use_stmt))))
+		   || types_compatible_p (TREE_TYPE (lhs),
+					  TREE_TYPE (TREE_OPERAND (def_rhs, 0))))
 	       /* Don't forward anything into clobber stmts if it would result
 		  in the lhs no longer being a MEM_REF.  */
 	       && (!gimple_clobber_p (use_stmt)
@@ -854,7 +857,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
 	  TREE_SIDE_EFFECTS (*def_rhs_basep) = TREE_SIDE_EFFECTS (lhs);
 	  TREE_THIS_NOTRAP (*def_rhs_basep) = TREE_THIS_NOTRAP (lhs);
 	  new_lhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
-	  gimple_assign_set_lhs (use_stmt, new_lhs);
+	  *lhsp = new_lhs;
 	  TREE_THIS_VOLATILE (new_lhs) = TREE_THIS_VOLATILE (lhs);
 	  TREE_SIDE_EFFECTS (new_lhs) = TREE_SIDE_EFFECTS (lhs);
 	  *def_rhs_basep = saved;
@@ -873,11 +876,12 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
 
   /* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR
      nodes from the RHS.  */
-  rhs = gimple_assign_rhs1 (use_stmt);
-  if (TREE_CODE (rhs) == ADDR_EXPR)
-    rhs = TREE_OPERAND (rhs, 0);
-  while (handled_component_p (rhs))
-    rhs = TREE_OPERAND (rhs, 0);
+  tree *rhsp = gimple_assign_rhs1_ptr (use_stmt);
+  if (TREE_CODE (*rhsp) == ADDR_EXPR)
+    rhsp = &TREE_OPERAND (*rhsp, 0);
+  while (handled_component_p (*rhsp))
+    rhsp = &TREE_OPERAND (*rhsp, 0);
+  rhs = *rhsp;
 
   /* Now see if the RHS node is a MEM_REF using NAME.  If so,
      propagate the ADDR_EXPR into the use of NAME and fold the result.  */
@@ -909,11 +913,13 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
       /* If the RHS is a plain dereference and the value type is the same as
          that of the pointed-to type of the address we can put the
 	 dereferenced address on the RHS preserving the original alias-type.  */
-      else if (gimple_assign_rhs1 (use_stmt) == rhs
-	       && integer_zerop (TREE_OPERAND (rhs, 1))
-	       && useless_type_conversion_p
-		    (TREE_TYPE (gimple_assign_lhs (use_stmt)),
-		     TREE_TYPE (TREE_OPERAND (def_rhs, 0))))
+      else if (integer_zerop (TREE_OPERAND (rhs, 1))
+	       && ((gimple_assign_rhs1 (use_stmt) == rhs
+		    && useless_type_conversion_p
+		         (TREE_TYPE (gimple_assign_lhs (use_stmt)),
+		          TREE_TYPE (TREE_OPERAND (def_rhs, 0))))
+		   || types_compatible_p (TREE_TYPE (rhs),
+					  TREE_TYPE (TREE_OPERAND (def_rhs, 0)))))
 	{
 	  tree *def_rhs_basep = &TREE_OPERAND (def_rhs, 0);
 	  tree new_offset, new_base, saved, new_rhs;
@@ -937,7 +943,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
 	  TREE_SIDE_EFFECTS (*def_rhs_basep) = TREE_SIDE_EFFECTS (rhs);
 	  TREE_THIS_NOTRAP (*def_rhs_basep) = TREE_THIS_NOTRAP (rhs);
 	  new_rhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
-	  gimple_assign_set_rhs1 (use_stmt, new_rhs);
+	  *rhsp = new_rhs;
 	  TREE_THIS_VOLATILE (new_rhs) = TREE_THIS_VOLATILE (rhs);
 	  TREE_SIDE_EFFECTS (new_rhs) = TREE_SIDE_EFFECTS (rhs);
 	  *def_rhs_basep = saved;