[PR,60640] When creating virtual clones, clone thunks too

Hi,

this patch fixes PR 60640 by creating thunks to clones when that is
necessary to properly redirect edges to them.  I mostly does what
cgraph_add_thunk does and what analyze_function does to thunks.  It
fixes the testcases on trunk (it does not apply to 4.8, I have not
looked how easily fixable that it) and passes bootstrap and testing on
x86_64-linux.

OK for trunk?

Thanks,

Martin


2014-03-26  Martin Jambor  <mjambor@suse.cz>

	* cgraph.h (cgraph_clone_node): New parameter added to declaration.
	Adjust all callers.
	* cgraphclones.c (build_function_type_skip_args): Moved upwards in the
	file.
	(build_function_decl_skip_args): Likewise.
	(duplicate_thunk_for_node): New function.
	(redirect_edge_duplicating_thunks): Likewise.
	(cgraph_clone_node): New parameter args_to_skip, pass it to
	redirect_edge_duplicating_thunks which is called instead of
	cgraph_redirect_edge_callee.
	(cgraph_create_virtual_clone): Pass args_to_skip to cgraph_clone_node.

testsuite/
	* g++.dg/ipa/pr60640-1.C: New test.
	* g++.dg/ipa/pr60640-2.C: Likewise.

> Hi,
> 
> this patch fixes PR 60640 by creating thunks to clones when that is
> necessary to properly redirect edges to them.  I mostly does what
> cgraph_add_thunk does and what analyze_function does to thunks.  It
> fixes the testcases on trunk (it does not apply to 4.8, I have not
> looked how easily fixable that it) and passes bootstrap and testing on
> x86_64-linux.
> 
> OK for trunk?
> 
> Thanks,
> 
> Martin
> 
> 
> 2014-03-26  Martin Jambor  <mjambor@suse.cz>
> 
> 	* cgraph.h (cgraph_clone_node): New parameter added to declaration.
> 	Adjust all callers.
> 	* cgraphclones.c (build_function_type_skip_args): Moved upwards in the
> 	file.
> 	(build_function_decl_skip_args): Likewise.
> 	(duplicate_thunk_for_node): New function.
> 	(redirect_edge_duplicating_thunks): Likewise.
> 	(cgraph_clone_node): New parameter args_to_skip, pass it to
> 	redirect_edge_duplicating_thunks which is called instead of
> 	cgraph_redirect_edge_callee.
> 	(cgraph_create_virtual_clone): Pass args_to_skip to cgraph_clone_node.
> +/* Duplicate thunk THUNK but make it to refer to NODE.  ARGS_TO_SKIP, if
> +   non-NULL, determines which parameters should be omitted.  */
> +
> +static cgraph_node *
> +duplicate_thunk_for_node (cgraph_node *thunk, cgraph_node *node,
> +			  bitmap args_to_skip)
> +{
> +  cgraph_node *new_thunk, *thunk_of;
> +  thunk_of = cgraph_function_or_thunk_node (thunk->callees->callee);
> +
> +  if (thunk_of->thunk.thunk_p)
> +    node = duplicate_thunk_for_node (thunk_of, node, args_to_skip);
> +
> +  tree new_decl;
> +  if (!args_to_skip)
> +    new_decl = copy_node (thunk->decl);
> +  else
> +    new_decl = build_function_decl_skip_args (thunk->decl, args_to_skip, false);
> +
> +  gcc_checking_assert (!DECL_STRUCT_FUNCTION (new_decl));
> +  gcc_checking_assert (!DECL_INITIAL (new_decl));
> +  gcc_checking_assert (!DECL_RESULT (new_decl));
> +  gcc_checking_assert (!DECL_RTL_SET_P (new_decl));
> +
> +  DECL_NAME (new_decl) = clone_function_name (thunk->decl, "artificial_thunk");
> +  SET_DECL_ASSEMBLER_NAME (new_decl, DECL_NAME (new_decl));
> +  DECL_EXTERNAL (new_decl) = 0;
> +  DECL_SECTION_NAME (new_decl) = NULL;
> +  DECL_COMDAT_GROUP (new_decl) = 0;
> +  TREE_PUBLIC (new_decl) = 0;
> +  DECL_COMDAT (new_decl) = 0;
> +  DECL_WEAK (new_decl) = 0;
> +  DECL_VIRTUAL_P (new_decl) = 0;
> +  DECL_STATIC_CONSTRUCTOR (new_decl) = 0;
> +  DECL_STATIC_DESTRUCTOR (new_decl) = 0;

We probably ought to factor out this to common subfunction.
> +
> +  new_thunk = cgraph_create_node (new_decl);
> +  new_thunk->definition = true;
> +  new_thunk->thunk = thunk->thunk;
> +  new_thunk->unique_name = in_lto_p;
> +  new_thunk->externally_visible = 0;
> +  new_thunk->local.local = 1;
> +  new_thunk->lowered = true;
> +  new_thunk->former_clone_of = thunk->decl;
> +
> +  struct cgraph_edge *e = cgraph_create_edge (new_thunk, node, NULL, 0,
> +					      CGRAPH_FREQ_BASE);
> +  e->call_stmt_cannot_inline_p = true;
> +  cgraph_call_edge_duplication_hooks (thunk->callees, e);
> +  if (!expand_thunk (new_thunk, false))
> +    new_thunk->analyzed = true;
> +  cgraph_call_node_duplication_hooks (thunk, new_thunk);
> +  return new_thunk;
> +}
> +
> +/* If E does not lead to a thunk, simply redirect it to N.  Otherwise create
> +   one or more equivalent thunks for N and redirect E to the first in the
> +   chain.  */
> +
> +void
> +redirect_edge_duplicating_thunks (struct cgraph_edge *e, struct cgraph_node *n,
> +				  bitmap args_to_skip)
> +{
> +  cgraph_node *orig_to = cgraph_function_or_thunk_node (e->callee);
> +  if (orig_to->thunk.thunk_p)
> +    n = duplicate_thunk_for_node (orig_to, n, args_to_skip);

Is there anything that would pevent us from creating a new thunk for each call?

Also I think you need to avoid this logic when THIS parameter is being optimized out
(i.e. it is part of skip_args)
Thanks for looking into this!

Honza

> Hi,
> 
> this patch fixes PR 60640 by creating thunks to clones when that is
> necessary to properly redirect edges to them.  I mostly does what
> cgraph_add_thunk does and what analyze_function does to thunks.  It
> fixes the testcases on trunk (it does not apply to 4.8, I have not
> looked how easily fixable that it) and passes bootstrap and testing on
> x86_64-linux.
> 
> OK for trunk?
> 
> Thanks,
> 
> Martin
> 
> 
> 2014-03-26  Martin Jambor  <mjambor@suse.cz>
> 
> 	* cgraph.h (cgraph_clone_node): New parameter added to declaration.
> 	Adjust all callers.
> 	* cgraphclones.c (build_function_type_skip_args): Moved upwards in the
> 	file.
> 	(build_function_decl_skip_args): Likewise.
> 	(duplicate_thunk_for_node): New function.
> 	(redirect_edge_duplicating_thunks): Likewise.
> 	(cgraph_clone_node): New parameter args_to_skip, pass it to
> 	redirect_edge_duplicating_thunks which is called instead of
> 	cgraph_redirect_edge_callee.
> 	(cgraph_create_virtual_clone): Pass args_to_skip to cgraph_clone_node.
> 
> testsuite/
> 	* g++.dg/ipa/pr60640-1.C: New test.
> 	* g++.dg/ipa/pr60640-2.C: Likewise.
> 
> Index: src/gcc/cgraph.h
> ===================================================================
> --- src.orig/gcc/cgraph.h
> +++ src/gcc/cgraph.h
> @@ -890,7 +890,7 @@ struct cgraph_edge * cgraph_clone_edge (
>  					unsigned, gcov_type, int, bool);
>  struct cgraph_node * cgraph_clone_node (struct cgraph_node *, tree, gcov_type,
>  					int, bool, vec<cgraph_edge_p>,
> -					bool, struct cgraph_node *);
> +					bool, struct cgraph_node *, bitmap);
>  tree clone_function_name (tree decl, const char *);
>  struct cgraph_node * cgraph_create_virtual_clone (struct cgraph_node *old_node,
>  			                          vec<cgraph_edge_p>,
> Index: src/gcc/cgraphclones.c
> ===================================================================
> --- src.orig/gcc/cgraphclones.c
> +++ src/gcc/cgraphclones.c
> @@ -168,6 +168,183 @@ cgraph_clone_edge (struct cgraph_edge *e
>    return new_edge;
>  }
>  
> +/* Build variant of function type ORIG_TYPE skipping ARGS_TO_SKIP and the
> +   return value if SKIP_RETURN is true.  */
> +
> +static tree
> +build_function_type_skip_args (tree orig_type, bitmap args_to_skip,
> +			       bool skip_return)
> +{
> +  tree new_type = NULL;
> +  tree args, new_args = NULL, t;
> +  tree new_reversed;
> +  int i = 0;
> +
> +  for (args = TYPE_ARG_TYPES (orig_type); args && args != void_list_node;
> +       args = TREE_CHAIN (args), i++)
> +    if (!args_to_skip || !bitmap_bit_p (args_to_skip, i))
> +      new_args = tree_cons (NULL_TREE, TREE_VALUE (args), new_args);
> +
> +  new_reversed = nreverse (new_args);
> +  if (args)
> +    {
> +      if (new_reversed)
> +        TREE_CHAIN (new_args) = void_list_node;
> +      else
> +	new_reversed = void_list_node;
> +    }
> +
> +  /* Use copy_node to preserve as much as possible from original type
> +     (debug info, attribute lists etc.)
> +     Exception is METHOD_TYPEs must have THIS argument.
> +     When we are asked to remove it, we need to build new FUNCTION_TYPE
> +     instead.  */
> +  if (TREE_CODE (orig_type) != METHOD_TYPE
> +      || !args_to_skip
> +      || !bitmap_bit_p (args_to_skip, 0))
> +    {
> +      new_type = build_distinct_type_copy (orig_type);
> +      TYPE_ARG_TYPES (new_type) = new_reversed;
> +    }
> +  else
> +    {
> +      new_type
> +        = build_distinct_type_copy (build_function_type (TREE_TYPE (orig_type),
> +							 new_reversed));
> +      TYPE_CONTEXT (new_type) = TYPE_CONTEXT (orig_type);
> +    }
> +
> +  if (skip_return)
> +    TREE_TYPE (new_type) = void_type_node;
> +
> +  /* This is a new type, not a copy of an old type.  Need to reassociate
> +     variants.  We can handle everything except the main variant lazily.  */
> +  t = TYPE_MAIN_VARIANT (orig_type);
> +  if (t != orig_type)
> +    {
> +      t = build_function_type_skip_args (t, args_to_skip, skip_return);
> +      TYPE_MAIN_VARIANT (new_type) = t;
> +      TYPE_NEXT_VARIANT (new_type) = TYPE_NEXT_VARIANT (t);
> +      TYPE_NEXT_VARIANT (t) = new_type;
> +    }
> +  else
> +    {
> +      TYPE_MAIN_VARIANT (new_type) = new_type;
> +      TYPE_NEXT_VARIANT (new_type) = NULL;
> +    }
> +
> +  return new_type;
> +}
> +
> +/* Build variant of function decl ORIG_DECL skipping ARGS_TO_SKIP and the
> +   return value if SKIP_RETURN is true.
> +
> +   Arguments from DECL_ARGUMENTS list can't be removed now, since they are
> +   linked by TREE_CHAIN directly.  The caller is responsible for eliminating
> +   them when they are being duplicated (i.e. copy_arguments_for_versioning).  */
> +
> +static tree
> +build_function_decl_skip_args (tree orig_decl, bitmap args_to_skip,
> +			       bool skip_return)
> +{
> +  tree new_decl = copy_node (orig_decl);
> +  tree new_type;
> +
> +  new_type = TREE_TYPE (orig_decl);
> +  if (prototype_p (new_type)
> +      || (skip_return && !VOID_TYPE_P (TREE_TYPE (new_type))))
> +    new_type
> +      = build_function_type_skip_args (new_type, args_to_skip, skip_return);
> +  TREE_TYPE (new_decl) = new_type;
> +
> +  /* For declarations setting DECL_VINDEX (i.e. methods)
> +     we expect first argument to be THIS pointer.   */
> +  if (args_to_skip && bitmap_bit_p (args_to_skip, 0))
> +    DECL_VINDEX (new_decl) = NULL_TREE;
> +
> +  /* When signature changes, we need to clear builtin info.  */
> +  if (DECL_BUILT_IN (new_decl)
> +      && args_to_skip
> +      && !bitmap_empty_p (args_to_skip))
> +    {
> +      DECL_BUILT_IN_CLASS (new_decl) = NOT_BUILT_IN;
> +      DECL_FUNCTION_CODE (new_decl) = (enum built_in_function) 0;
> +    }
> +  /* The FE might have information and assumptions about the other
> +     arguments.  */
> +  DECL_LANG_SPECIFIC (new_decl) = NULL;
> +  return new_decl;
> +}
> +
> +/* Duplicate thunk THUNK but make it to refer to NODE.  ARGS_TO_SKIP, if
> +   non-NULL, determines which parameters should be omitted.  */
> +
> +static cgraph_node *
> +duplicate_thunk_for_node (cgraph_node *thunk, cgraph_node *node,
> +			  bitmap args_to_skip)
> +{
> +  cgraph_node *new_thunk, *thunk_of;
> +  thunk_of = cgraph_function_or_thunk_node (thunk->callees->callee);
> +
> +  if (thunk_of->thunk.thunk_p)
> +    node = duplicate_thunk_for_node (thunk_of, node, args_to_skip);
> +
> +  tree new_decl;
> +  if (!args_to_skip)
> +    new_decl = copy_node (thunk->decl);
> +  else
> +    new_decl = build_function_decl_skip_args (thunk->decl, args_to_skip, false);
> +
> +  gcc_checking_assert (!DECL_STRUCT_FUNCTION (new_decl));
> +  gcc_checking_assert (!DECL_INITIAL (new_decl));
> +  gcc_checking_assert (!DECL_RESULT (new_decl));
> +  gcc_checking_assert (!DECL_RTL_SET_P (new_decl));
> +
> +  DECL_NAME (new_decl) = clone_function_name (thunk->decl, "artificial_thunk");
> +  SET_DECL_ASSEMBLER_NAME (new_decl, DECL_NAME (new_decl));
> +  DECL_EXTERNAL (new_decl) = 0;
> +  DECL_SECTION_NAME (new_decl) = NULL;
> +  DECL_COMDAT_GROUP (new_decl) = 0;
> +  TREE_PUBLIC (new_decl) = 0;
> +  DECL_COMDAT (new_decl) = 0;
> +  DECL_WEAK (new_decl) = 0;
> +  DECL_VIRTUAL_P (new_decl) = 0;
> +  DECL_STATIC_CONSTRUCTOR (new_decl) = 0;
> +  DECL_STATIC_DESTRUCTOR (new_decl) = 0;
> +
> +  new_thunk = cgraph_create_node (new_decl);
> +  new_thunk->definition = true;
> +  new_thunk->thunk = thunk->thunk;
> +  new_thunk->unique_name = in_lto_p;
> +  new_thunk->externally_visible = 0;
> +  new_thunk->local.local = 1;
> +  new_thunk->lowered = true;
> +  new_thunk->former_clone_of = thunk->decl;
> +
> +  struct cgraph_edge *e = cgraph_create_edge (new_thunk, node, NULL, 0,
> +					      CGRAPH_FREQ_BASE);
> +  e->call_stmt_cannot_inline_p = true;
> +  cgraph_call_edge_duplication_hooks (thunk->callees, e);
> +  if (!expand_thunk (new_thunk, false))
> +    new_thunk->analyzed = true;
> +  cgraph_call_node_duplication_hooks (thunk, new_thunk);
> +  return new_thunk;
> +}
> +
> +/* If E does not lead to a thunk, simply redirect it to N.  Otherwise create
> +   one or more equivalent thunks for N and redirect E to the first in the
> +   chain.  */
> +
> +void
> +redirect_edge_duplicating_thunks (struct cgraph_edge *e, struct cgraph_node *n,
> +				  bitmap args_to_skip)
> +{
> +  cgraph_node *orig_to = cgraph_function_or_thunk_node (e->callee);
> +  if (orig_to->thunk.thunk_p)
> +    n = duplicate_thunk_for_node (orig_to, n, args_to_skip);
> +
> +  cgraph_redirect_edge_callee (e, n);
> +}
>  
>  /* Create node representing clone of N executed COUNT times.  Decrease
>     the execution counts from original node too.
> @@ -190,7 +367,8 @@ cgraph_clone_node (struct cgraph_node *n
>  		   bool update_original,
>  		   vec<cgraph_edge_p> redirect_callers,
>  		   bool call_duplication_hook,
> -		   struct cgraph_node *new_inlined_to)
> +		   struct cgraph_node *new_inlined_to,
> +		   bitmap args_to_skip)
>  {
>    struct cgraph_node *new_node = cgraph_create_empty_node ();
>    struct cgraph_edge *e;
> @@ -239,7 +417,7 @@ cgraph_clone_node (struct cgraph_node *n
>      {
>        /* Redirect calls to the old version node to point to its new
>  	 version.  */
> -      cgraph_redirect_edge_callee (e, new_node);
> +      redirect_edge_duplicating_thunks (e, new_node, args_to_skip);
>      }
>  
>  
> @@ -288,114 +466,6 @@ clone_function_name (tree decl, const ch
>    return get_identifier (tmp_name);
>  }
>  
> -/* Build variant of function type ORIG_TYPE skipping ARGS_TO_SKIP and the
> -   return value if SKIP_RETURN is true.  */
> -
> -static tree
> -build_function_type_skip_args (tree orig_type, bitmap args_to_skip,
> -			       bool skip_return)
> -{
> -  tree new_type = NULL;
> -  tree args, new_args = NULL, t;
> -  tree new_reversed;
> -  int i = 0;
> -
> -  for (args = TYPE_ARG_TYPES (orig_type); args && args != void_list_node;
> -       args = TREE_CHAIN (args), i++)
> -    if (!args_to_skip || !bitmap_bit_p (args_to_skip, i))
> -      new_args = tree_cons (NULL_TREE, TREE_VALUE (args), new_args);
> -
> -  new_reversed = nreverse (new_args);
> -  if (args)
> -    {
> -      if (new_reversed)
> -        TREE_CHAIN (new_args) = void_list_node;
> -      else
> -	new_reversed = void_list_node;
> -    }
> -
> -  /* Use copy_node to preserve as much as possible from original type
> -     (debug info, attribute lists etc.)
> -     Exception is METHOD_TYPEs must have THIS argument.
> -     When we are asked to remove it, we need to build new FUNCTION_TYPE
> -     instead.  */
> -  if (TREE_CODE (orig_type) != METHOD_TYPE
> -      || !args_to_skip
> -      || !bitmap_bit_p (args_to_skip, 0))
> -    {
> -      new_type = build_distinct_type_copy (orig_type);
> -      TYPE_ARG_TYPES (new_type) = new_reversed;
> -    }
> -  else
> -    {
> -      new_type
> -        = build_distinct_type_copy (build_function_type (TREE_TYPE (orig_type),
> -							 new_reversed));
> -      TYPE_CONTEXT (new_type) = TYPE_CONTEXT (orig_type);
> -    }
> -
> -  if (skip_return)
> -    TREE_TYPE (new_type) = void_type_node;
> -
> -  /* This is a new type, not a copy of an old type.  Need to reassociate
> -     variants.  We can handle everything except the main variant lazily.  */
> -  t = TYPE_MAIN_VARIANT (orig_type);
> -  if (t != orig_type)
> -    {
> -      t = build_function_type_skip_args (t, args_to_skip, skip_return);
> -      TYPE_MAIN_VARIANT (new_type) = t;
> -      TYPE_NEXT_VARIANT (new_type) = TYPE_NEXT_VARIANT (t);
> -      TYPE_NEXT_VARIANT (t) = new_type;
> -    }
> -  else
> -    {
> -      TYPE_MAIN_VARIANT (new_type) = new_type;
> -      TYPE_NEXT_VARIANT (new_type) = NULL;
> -    }
> -
> -  return new_type;
> -}
> -
> -/* Build variant of function decl ORIG_DECL skipping ARGS_TO_SKIP and the
> -   return value if SKIP_RETURN is true.
> -
> -   Arguments from DECL_ARGUMENTS list can't be removed now, since they are
> -   linked by TREE_CHAIN directly.  The caller is responsible for eliminating
> -   them when they are being duplicated (i.e. copy_arguments_for_versioning).  */
> -
> -static tree
> -build_function_decl_skip_args (tree orig_decl, bitmap args_to_skip,
> -			       bool skip_return)
> -{
> -  tree new_decl = copy_node (orig_decl);
> -  tree new_type;
> -
> -  new_type = TREE_TYPE (orig_decl);
> -  if (prototype_p (new_type)
> -      || (skip_return && !VOID_TYPE_P (TREE_TYPE (new_type))))
> -    new_type
> -      = build_function_type_skip_args (new_type, args_to_skip, skip_return);
> -  TREE_TYPE (new_decl) = new_type;
> -
> -  /* For declarations setting DECL_VINDEX (i.e. methods)
> -     we expect first argument to be THIS pointer.   */
> -  if (args_to_skip && bitmap_bit_p (args_to_skip, 0))
> -    DECL_VINDEX (new_decl) = NULL_TREE;
> -
> -  /* When signature changes, we need to clear builtin info.  */
> -  if (DECL_BUILT_IN (new_decl)
> -      && args_to_skip
> -      && !bitmap_empty_p (args_to_skip))
> -    {
> -      DECL_BUILT_IN_CLASS (new_decl) = NOT_BUILT_IN;
> -      DECL_FUNCTION_CODE (new_decl) = (enum built_in_function) 0;
> -    }
> -  /* The FE might have information and assumptions about the other
> -     arguments.  */
> -  DECL_LANG_SPECIFIC (new_decl) = NULL;
> -  return new_decl;
> -}
> -
>  /* Create callgraph node clone with new declaration.  The actual body will
>     be copied later at compilation stage.
>  
> @@ -449,7 +519,7 @@ cgraph_create_virtual_clone (struct cgra
>  
>    new_node = cgraph_clone_node (old_node, new_decl, old_node->count,
>  				CGRAPH_FREQ_BASE, false,
> -				redirect_callers, false, NULL);
> +				redirect_callers, false, NULL, args_to_skip);
>    /* Update the properties.
>       Make clone visible only within this translation unit.  Make sure
>       that is not weak also.
> Index: src/gcc/ipa-inline-transform.c
> ===================================================================
> --- src.orig/gcc/ipa-inline-transform.c
> +++ src/gcc/ipa-inline-transform.c
> @@ -184,7 +184,7 @@ clone_inlined_nodes (struct cgraph_edge
>  	    freq_scale = e->frequency;
>  	  n = cgraph_clone_node (e->callee, e->callee->decl,
>  				 e->count, freq_scale, update_original,
> -				 vNULL, true, inlining_into);
> +				 vNULL, true, inlining_into, NULL);
>  	  cgraph_redirect_edge_callee (e, n);
>  	}
>      }
> Index: src/gcc/ipa-inline.c
> ===================================================================
> --- src.orig/gcc/ipa-inline.c
> +++ src/gcc/ipa-inline.c
> @@ -1388,7 +1388,7 @@ recursive_inlining (struct cgraph_edge *
>  	  /* We need original clone to copy around.  */
>  	  master_clone = cgraph_clone_node (node, node->decl,
>  					    node->count, CGRAPH_FREQ_BASE,
> -					    false, vNULL, true, NULL);
> +					    false, vNULL, true, NULL, NULL);
>  	  for (e = master_clone->callees; e; e = e->next_callee)
>  	    if (!e->inline_failed)
>  	      clone_inlined_nodes (e, true, false, NULL, CGRAPH_FREQ_BASE);
> Index: src/gcc/lto-cgraph.c
> ===================================================================
> --- src.orig/gcc/lto-cgraph.c
> +++ src/gcc/lto-cgraph.c
> @@ -1042,7 +1042,7 @@ input_node (struct lto_file_decl_data *f
>      {
>        node = cgraph_clone_node (cgraph (nodes[clone_ref]), fn_decl,
>  				0, CGRAPH_FREQ_BASE, false,
> -				vNULL, false, NULL);
> +				vNULL, false, NULL, NULL);
>      }
>    else
>      {
> Index: src/gcc/testsuite/g++.dg/ipa/pr60640-1.C
> ===================================================================
> --- /dev/null
> +++ src/gcc/testsuite/g++.dg/ipa/pr60640-1.C
> @@ -0,0 +1,50 @@
> +// { dg-do compile }
> +// { dg-options "-O3" }
> +
> +class ASN1Object
> +{
> +public:
> +  virtual ~ASN1Object ();
> +};
> +class A
> +{
> +  virtual unsigned m_fn1 () const;
> +};
> +class B
> +{
> +public:
> +  ASN1Object Element;
> +  virtual unsigned m_fn1 (bool) const;
> +};
> +template <class BASE> class C : public BASE
> +{
> +};
> +
> +class D : ASN1Object, public B
> +{
> +};
> +class G : public D
> +{
> +  unsigned m_fn1 (bool) const {}
> +};
> +class F : A
> +{
> +public:
> +  F (A);
> +  unsigned m_fn1 () const
> +  {
> +    int a;
> +    a = m_fn2 ().m_fn1 (0);
> +    return a;
> +  }
> +  const B &m_fn2 () const { return m_groupParameters; }
> +  C<G> m_groupParameters;
> +};
> +template <class D> void BenchMarkKeyAgreement (int *, int *, int)
> +{
> +  A f;
> +  D d (f);
> +}
> +
> +void BenchmarkAll2 () { BenchMarkKeyAgreement<F>(0, 0, 0); }
> +