Problem with SSA form usign cgraph_nodes and push_cfun

Problem with SSA form usign cgraph_nodes and push_cfun

[Massimo Nazaria]

Hi everybody!
I am working on a gcc-pass which processes every statement using this code:

  for (node = cgraph_nodes; node; node = node->next)
    {
      if (node->analyzed && cgraph_is_master_clone (node))
        {
          push_cfun (DECL_STRUCT_FUNCTION (node->decl));
          
          FOR_EACH_BB (bb)
            {
            // Here I would like to use SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));


With the code above I can't use SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt)) (I get 'segmentation fault'). I think the reason is that the statements are not in SSA-form.

Insead, if I use

  FOR_EACH_BB (bb) { ... }

without using "for (node = graph_nodes; ...", I have the statements in SSA-form and SSA_NAME_DEF_STMT is OK.

Unfortunately, with this solution, I can not process every function at once...

How can I do to use SSA_NAME_DEF_STMT while processing every function?

Thank you!

Max

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Richard Guenther]

On Thu, Apr 29, 2010 at 7:28 PM, Massimo Nazaria <max_n@rocketmail.com> wrote:
> Hi everybody!
> I am working on a gcc-pass which processes every statement using this code:
>
>  for (node = cgraph_nodes; node; node = node->next)
>    {
>      if (node->analyzed && cgraph_is_master_clone (node))
>        {
>          push_cfun (DECL_STRUCT_FUNCTION (node->decl));
>
>          FOR_EACH_BB (bb)
>            {
>            // Here I would like to use SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
>
>
> With the code above I can't use SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt)) (I get 'segmentation fault'). I think the reason is that the statements are not in SSA-form.
>
> Insead, if I use
>
>  FOR_EACH_BB (bb) { ... }
>
> without using "for (node = graph_nodes; ...", I have the statements in SSA-form and SSA_NAME_DEF_STMT is OK.
>
> Unfortunately, with this solution, I can not process every function at once...
>
> How can I do to use SSA_NAME_DEF_STMT while processing every function?

You have to schedule your IPA pass at a point where the whole
program is in SSA form, which is during the regular IPA passes
at earlierst.

Richard.

> Thank you!
>
> Max
>
>
>
>
>

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Massimo Nazaria]

> You have to schedule your IPA pass at a point where the
> whole
> program is in SSA form, which is during the regular IPA
> passes
> at earlierst.
> 
> Richard.
> 

It does not work :(
I put my pass after all the ipa-passes and right before the optimization-passes.

My problem occurs when I try to process every function at once using "for(node=cgraph_nodes;node;node=node->next) ..."

Other ideas?

Thank you!

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Richard Guenther]

On Fri, Apr 30, 2010 at 1:42 PM, Massimo Nazaria <max_n@rocketmail.com> wrote:
>> You have to schedule your IPA pass at a point where the
>> whole
>> program is in SSA form, which is during the regular IPA
>> passes
>> at earlierst.
>>
>> Richard.
>>
>
> It does not work :(
> I put my pass after all the ipa-passes and right before the optimization-passes.
>
> My problem occurs when I try to process every function at once using "for(node=cgraph_nodes;node;node=node->next) ..."

It definitely works that way.

Richard.

> Other ideas?
>
> Thank you!
>
>
>
>

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Steven Bosscher]

On Fri, Apr 30, 2010 at 1:42 PM, Massimo Nazaria <max_n@rocketmail.com> wrote:
>> You have to schedule your IPA pass at a point where the
>> whole
>> program is in SSA form, which is during the regular IPA
>> passes
>> at earlierst.
>>
>> Richard.
>>
>
> It does not work :(
> I put my pass after all the ipa-passes and right before the optimization-passes.
>
> My problem occurs when I try to process every function at once using "for(node=cgraph_nodes;node;node=node->next) ..."
>
> Other ideas?

You'll have to post your work so people can see. Now the best the
experts here can do is guess what you're holding behind your back :-)

Ciao!
Steven

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Massimo Nazaria]

> You'll have to post your work so people can see. Now the
> best the
> experts here can do is guess what you're holding behind
> your back :-)
> 
> Ciao!
> Steven
> 

I completely agree with you. This is my pass:

static unsigned int
execute_mypass (void)
{
  basic_block bb;
  gimple stmt, def_stmt;
  gimple_stmt_iterator gsi;
  struct cgraph_node *node;
  unsigned int rhs_code_class;
  
  if (flag_mypass)
    {
      for (node = cgraph_nodes; node; node = node->next)
        {
          if (node->analyzed && cgraph_is_master_clone (node))
          	{
          	  push_cfun (DECL_STRUCT_FUNCTION (node->decl));
          	  
              FOR_EACH_BB (bb)
                {
                  for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
                    {
                      stmt = gsi_stmt (gsi);
                      
                      if (gimple_code (stmt) == GIMPLE_ASSIGN)
                        {
                        /* Check if the assignment is acctually 
                           a function call. For example:
                             D.1 = func (args...);
                             a.9 = D.1
                             a = a.9
                          The last one is seen as a GIMPLE_ASSIGN stmt 
                          but I want to check if it refers to a function call */

                          rhs_code_class = get_gimple_rhs_class (gimple_assign_rhs_code (stmt));
                          if ((rhs_code_class == GIMPLE_UNARY_RHS) || (rhs_code_class == GIMPLE_SINGLE_RHS))
                            {
                              if (is_temporary_var (gimple_assign_rhs1 (stmt))) // e.g.: a.1, D.1234...
                                {
                                  def_stmt = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
                                  
                                  fprintf (dump_file, "gimple_code: %d\n", gimple_code (def_stmt)); // Here I get segmentation fault...
                                }
                            }
                        }
                    }
                }
              pop_cfun ();
            }
        }
    }
  
  return 0;
}

The problem is that "SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt))" does not return a gimple stmt. I think that's because, when I make a dump of the stmts with the code above, this one has not the SSA-form. But if only use the FOR_EACH (bb), without "for (node = cgraph_nodes; ...", the SS-form is OK and SSA_NAME_DEF_STMT works well.

How can I do?

Thank you!

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Steven Bosscher]

On Fri, Apr 30, 2010 at 3:35 PM, Massimo Nazaria <max_n@rocketmail.com> wrote:
>> You'll have to post your work so people can see. Now the
>> best the
>> experts here can do is guess what you're holding behind
>> your back :-)
>>
>> Ciao!
>> Steven
>>
>
> I completely agree with you. This is my pass:

The place where you insert the patch is as important as the
implementation of your patch. What do your changes to passes.c look
like?

Ciao!
Steven

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Massimo Nazaria]

> The place where you insert the patch is as important as
> the
> implementation of your patch. What do your changes to
> passes.c look
> like?

Here is the "passes.c":

   NEXT_PASS (pass_early_warn_uninitialized);
   NEXT_PASS (pass_all_early_optimizations);
      
   NEXT_PASS (pass_mypass);  // My pass...
      
	{
	  struct opt_pass **p = &pass_all_early_optimizations.pass.sub;
	  NEXT_PASS (pass_rebuild_cgraph_edges);

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Diego Novillo]

On 4/30/10 09:35 , Massimo Nazaria wrote:

>                                   fprintf (dump_file, "gimple_code: %d\n", gimple_code (def_stmt)); // Here I get segmentation fault...

For default SSA names, the defining statement will be NULL.  A default
SSA name will be created when a symbol is never written before its first
read (e.g., function parameters are typical).


Diego.

PS: It's usually better to post the output of 'svn diff' so we can see
*all* your changes and possibly apply them into our own local trees for
testing.

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Richard Guenther]

On Fri, Apr 30, 2010 at 3:35 PM, Massimo Nazaria <max_n@rocketmail.com> wrote:
>> You'll have to post your work so people can see. Now the
>> best the
>> experts here can do is guess what you're holding behind
>> your back :-)
>>
>> Ciao!
>> Steven
>>
>
> I completely agree with you. This is my pass:
>
> static unsigned int
> execute_mypass (void)
> {
>  basic_block bb;
>  gimple stmt, def_stmt;
>  gimple_stmt_iterator gsi;
>  struct cgraph_node *node;
>  unsigned int rhs_code_class;
>
>  if (flag_mypass)
>    {
>      for (node = cgraph_nodes; node; node = node->next)
>        {
>          if (node->analyzed && cgraph_is_master_clone (node))
>                {
>                  push_cfun (DECL_STRUCT_FUNCTION (node->decl));
>
>              FOR_EACH_BB (bb)
>                {
>                  for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
>                    {
>                      stmt = gsi_stmt (gsi);
>
>                      if (gimple_code (stmt) == GIMPLE_ASSIGN)
>                        {
>                        /* Check if the assignment is acctually
>                           a function call. For example:
>                             D.1 = func (args...);
>                             a.9 = D.1
>                             a = a.9
>                          The last one is seen as a GIMPLE_ASSIGN stmt
>                          but I want to check if it refers to a function call */
>
>                          rhs_code_class = get_gimple_rhs_class (gimple_assign_rhs_code (stmt));
>                          if ((rhs_code_class == GIMPLE_UNARY_RHS) || (rhs_code_class == GIMPLE_SINGLE_RHS))
>                            {
>                              if (is_temporary_var (gimple_assign_rhs1 (stmt))) // e.g.: a.1, D.1234...

This check is critical - if it is not verifying that
TREE_CODE (gimple_Assign_rhs1 (Stmt)) == SSA_NAME then
it's wrong.

>                                {
>                                  def_stmt = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt));
>
>                                  fprintf (dump_file, "gimple_code: %d\n", gimple_code (def_stmt)); // Here I get segmentation fault...
>                                }
>                            }
>                        }
>                    }
>                }
>              pop_cfun ();
>            }
>        }
>    }
>
>  return 0;
> }
>
> The problem is that "SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt))" does not return a gimple stmt. I think that's because, when I make a dump of the stmts with the code above, this one has not the SSA-form. But if only use the FOR_EACH (bb), without "for (node = cgraph_nodes; ...", the SS-form is OK and SSA_NAME_DEF_STMT works well.
>
> How can I do?
>
> Thank you!
>
>
>
>

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Michael Matz]

Hi,

On Fri, 30 Apr 2010, Diego Novillo wrote:

> On 4/30/10 09:35 , Massimo Nazaria wrote:
> 
> >                                   fprintf (dump_file, "gimple_code: %d\n", gimple_code (def_stmt)); // Here I get segmentation fault...
> 
> For default SSA names, the defining statement will be NULL.

Nope, it will be non-NULL but gimple_nop_p().


Ciao,
Michael.

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Diego Novillo]

On Fri, Apr 30, 2010 at 10:48, Michael Matz <matz@suse.de> wrote:

>> For default SSA names, the defining statement will be NULL.
>
> Nope, it will be non-NULL but gimple_nop_p().

Bah!  yes, of course.  Sorry about that.


Diego.

Re: Problem with SSA form usign cgraph_nodes and push_cfun

[Massimo Nazaria]

Thank you everyone!!!
I found out a solution...

I had to add a line to my pass (the 2nd if):
for (node = cgraph_nodes; node; node = node->next) {
  if (node->analyzed && cgraph_is_master_clone (node)) {
    if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))) return 0; // I added this line

In my case, the remaining code of the pass is executed only when the pass-manager is working on the last function of the input program. Now I can process every function at once, and the statements are in SSA-form.

Thank you again!

Max