Don't dump low gimple functions in gimple dump

Hi!

It's just been a year.  ;-P

In early March, I (hopefully correctly) adapted Tom's patch to apply to
then-current GCC trunk sources; posting this here.  Is the general
approach OK?

On Tue, 20 May 2014 10:16:45 +0200, Tom de Vries <Tom_deVries@mentor.com> wrote:
> Honza,
> 
> Consider this program:
> ...
> int
> main(void)
> {
> #pragma omp parallel
>   {
>     extern void foo(void);
>     foo ();
>   }
>   return 0;
> }
> ...
> 
> When compiling this program with -fopenmp, the ompexp pass splits off a new
> function called main._omp_fn.0 containing the call to foo.  The new function is
> then dumped into the gimple dump by analyze_function.
> 
> There are two problems with this:
> - the new function is in low gimple, and is dumped next to high gimple
>   functions
> - since it's already low, the new function is not lowered, and 'goes missing'
>   in the dumps following the gimple dump, until it reappears again after the
>   last lowering dump.
>   [ http://gcc.gnu.org/ml/gcc/2014-03/msg00312.html ]
> 
> This patch fixes the problems by ensuring that analyze_function only dumps the
> new function to the gimple dump after gimplification (specifically, by moving
> the dump_function call into gimplify_function_tree.  That makes the call to
> dump_function in finalize_size_functions superfluous).
> 
> That also requires us to add a call to dump_function in finalize_task_copyfn,
> where we split off a new high gimple function.
> 
> And in expand_omp_taskreg and expand_omp_target, where we split off a new low
> gimple function, we now dump the new function into the current (ompexp) dump
> file, which is the last lowering dump.
> 
> Finally, we dump an information statement at the start of
> cgraph_add_new_function to give a better idea when and what kind of function is
> created.
> 
> Bootstrapped and reg-tested on x86_64.
> 
> OK for trunk ?
> 
> Thanks,
> - Tom

commit b925b393c3d975a9281789d97aff8a91a8b53be0
Author: Thomas Schwinge <thomas@codesourcery.com>
Date:   Sun Mar 1 15:05:15 2015 +0100

    Don't dump low gimple functions in gimple dump
    
    id:"537B0F6D.7060808@mentor.com" or id:"53734DC5.90001@mentor.com"
    
    2014-05-19  Tom de Vries  <tom@codesourcery.com>
    
    	* cgraphunit.c (cgraph_add_new_function): Dump message on new function.
    	(analyze_function): Don't dump function to gimple dump file.
    	* gimplify.c: Add tree-dump.h include.
    	(gimplify_function_tree): Dump function to gimple dump file.
    	* omp-low.c: Add tree-dump.h include.
    	(finalize_task_copyfn): Dump new function to gimple dump file.
    	(expand_omp_taskreg, expand_omp_target): Dump new function to dump file.
    	* stor-layout.c (finalize_size_functions): Don't dump function to gimple
    	dump file.
    
    	* gcc.dg/gomp/dump-task.c: New test.
---
 gcc/cgraphunit.c                      | 15 ++++++++++++++-
 gcc/gimplify.c                        |  3 +++
 gcc/omp-low.c                         |  6 ++++++
 gcc/stor-layout.c                     |  1 -
 gcc/testsuite/gcc.dg/gomp/dump-task.c | 33 +++++++++++++++++++++++++++++++++
 5 files changed, 56 insertions(+), 2 deletions(-)



Grüße,
 Thomas

On Thu, May 21, 2015 at 5:36 PM, Thomas Schwinge
<thomas@codesourcery.com> wrote:
> Hi!
>
> It's just been a year.  ;-P
>
> In early March, I (hopefully correctly) adapted Tom's patch to apply to
> then-current GCC trunk sources; posting this here.  Is the general
> approach OK?
>
> On Tue, 20 May 2014 10:16:45 +0200, Tom de Vries <Tom_deVries@mentor.com> wrote:
>> Honza,
>>
>> Consider this program:
>> ...
>> int
>> main(void)
>> {
>> #pragma omp parallel
>>   {
>>     extern void foo(void);
>>     foo ();
>>   }
>>   return 0;
>> }
>> ...
>>
>> When compiling this program with -fopenmp, the ompexp pass splits off a new
>> function called main._omp_fn.0 containing the call to foo.  The new function is
>> then dumped into the gimple dump by analyze_function.
>>
>> There are two problems with this:
>> - the new function is in low gimple, and is dumped next to high gimple
>>   functions
>> - since it's already low, the new function is not lowered, and 'goes missing'
>>   in the dumps following the gimple dump, until it reappears again after the
>>   last lowering dump.
>>   [ http://gcc.gnu.org/ml/gcc/2014-03/msg00312.html ]
>>
>> This patch fixes the problems by ensuring that analyze_function only dumps the
>> new function to the gimple dump after gimplification (specifically, by moving
>> the dump_function call into gimplify_function_tree.  That makes the call to
>> dump_function in finalize_size_functions superfluous).
>>
>> That also requires us to add a call to dump_function in finalize_task_copyfn,
>> where we split off a new high gimple function.
>>
>> And in expand_omp_taskreg and expand_omp_target, where we split off a new low
>> gimple function, we now dump the new function into the current (ompexp) dump
>> file, which is the last lowering dump.
>>
>> Finally, we dump an information statement at the start of
>> cgraph_add_new_function to give a better idea when and what kind of function is
>> created.
>>
>> Bootstrapped and reg-tested on x86_64.
>>
>> OK for trunk ?
>>
>> Thanks,
>> - Tom
>
> commit b925b393c3d975a9281789d97aff8a91a8b53be0
> Author: Thomas Schwinge <thomas@codesourcery.com>
> Date:   Sun Mar 1 15:05:15 2015 +0100
>
>     Don't dump low gimple functions in gimple dump
>
>     id:"537B0F6D.7060808@mentor.com" or id:"53734DC5.90001@mentor.com"
>
>     2014-05-19  Tom de Vries  <tom@codesourcery.com>
>
>         * cgraphunit.c (cgraph_add_new_function): Dump message on new function.
>         (analyze_function): Don't dump function to gimple dump file.
>         * gimplify.c: Add tree-dump.h include.
>         (gimplify_function_tree): Dump function to gimple dump file.
>         * omp-low.c: Add tree-dump.h include.
>         (finalize_task_copyfn): Dump new function to gimple dump file.
>         (expand_omp_taskreg, expand_omp_target): Dump new function to dump file.
>         * stor-layout.c (finalize_size_functions): Don't dump function to gimple
>         dump file.
>
>         * gcc.dg/gomp/dump-task.c: New test.
> ---
>  gcc/cgraphunit.c                      | 15 ++++++++++++++-
>  gcc/gimplify.c                        |  3 +++
>  gcc/omp-low.c                         |  6 ++++++
>  gcc/stor-layout.c                     |  1 -
>  gcc/testsuite/gcc.dg/gomp/dump-task.c | 33 +++++++++++++++++++++++++++++++++
>  5 files changed, 56 insertions(+), 2 deletions(-)
>
> diff --git gcc/cgraphunit.c gcc/cgraphunit.c
> index 8280fc4..0860c86 100644
> --- gcc/cgraphunit.c
> +++ gcc/cgraphunit.c
> @@ -501,6 +501,20 @@ cgraph_node::add_new_function (tree fndecl, bool lowered)
>  {
>    gcc::pass_manager *passes = g->get_passes ();
>    cgraph_node *node;
> +
> +  if (dump_file)
> +    {
> +      const char *function_type = ((gimple_has_body_p (fndecl))
> +                                  ? (lowered
> +                                     ? "low gimple"
> +                                     : "high gimple")
> +                                  : "to-be-gimplified");
> +      fprintf (dump_file,
> +              "Added new %s function %s to callgraph\n",
> +              function_type,
> +              fndecl_name (fndecl));
> +    }
> +
>    switch (symtab->state)
>      {
>        case PARSING:
> @@ -629,7 +643,6 @@ cgraph_node::analyze (void)
>          body.  */
>        if (!gimple_has_body_p (decl))
>         gimplify_function_tree (decl);
> -      dump_function (TDI_generic, decl);
>
>        /* Lower the function.  */
>        if (!lowered)
> diff --git gcc/gimplify.c gcc/gimplify.c
> index 9214648..d6c500d 100644
> --- gcc/gimplify.c
> +++ gcc/gimplify.c
> @@ -87,6 +87,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "gimple-low.h"
>  #include "cilk.h"
>  #include "gomp-constants.h"
> +#include "tree-dump.h"
>
>  #include "langhooks-def.h"     /* FIXME: for lhd_set_decl_assembler_name */
>  #include "tree-pass.h"         /* FIXME: only for PROP_gimple_any */
> @@ -9435,6 +9436,8 @@ gimplify_function_tree (tree fndecl)
>    cfun->curr_properties = PROP_gimple_any;
>
>    pop_cfun ();
> +
> +  dump_function (TDI_generic, fndecl);

Err - that dumps gimple now.  I think the dump you removed above was
simply bogus
and should have used TDI_gimple?  Or is TDI_generic just misnamed?

Ah, indeed.  There is TDI_original (for .original, aka GENERIC) and TDI_generic
for .gimple.

>  }
>
>  /* Return a dummy expression of type TYPE in order to keep going after an
> diff --git gcc/omp-low.c gcc/omp-low.c
> index fac32b3..2839d8f 100644
> --- gcc/omp-low.c
> +++ gcc/omp-low.c
> @@ -109,6 +109,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "lto-section-names.h"
>  #include "gomp-constants.h"
>  #include "gimple-pretty-print.h"
> +#include "tree-dump.h"
>
>
>  /* Lowering of OMP parallel and workshare constructs proceeds in two
> @@ -1714,6 +1715,7 @@ finalize_task_copyfn (gomp_task *task_stmt)
>    pop_cfun ();
>
>    /* Inform the callgraph about the new function.  */
> +  dump_function (TDI_generic, child_fn);

And this would be duplicate?

>    cgraph_node::add_new_function (child_fn, false);
>  }
>
> @@ -6073,6 +6075,8 @@ expand_omp_taskreg (struct omp_region *region)
>        /* Inform the callgraph about the new function.  */
>        DECL_STRUCT_FUNCTION (child_fn)->curr_properties = cfun->curr_properties;
>        cgraph_node::add_new_function (child_fn, true);
> +      if (dump_file)
> +       dump_function_to_file (child_fn, dump_file, dump_flags);
>
>        /* Fix the callgraph edges for child_cfun.  Those for cfun will be
>          fixed in a following pass.  */
> @@ -9527,6 +9531,8 @@ expand_omp_target (struct omp_region *region)
>        /* Inform the callgraph about the new function.  */
>        DECL_STRUCT_FUNCTION (child_fn)->curr_properties = cfun->curr_properties;
>        cgraph_node::add_new_function (child_fn, true);
> +      if (dump_file)
> +       dump_function_to_file (child_fn, dump_file, dump_flags);

So why does add_new_function not do the dumping and to the correct
place?  That is,
you are dumping things twice here, once in omp expansion and then again when the
new function reaches omp expansion?

>  #ifdef ENABLE_OFFLOADING
>        /* Add the new function to the offload table.  */
> diff --git gcc/stor-layout.c gcc/stor-layout.c
> index 273a12b..b3f9852 100644
> --- gcc/stor-layout.c
> +++ gcc/stor-layout.c
> @@ -318,7 +318,6 @@ finalize_size_functions (void)
>        set_cfun (NULL);
>        dump_function (TDI_original, fndecl);
>        gimplify_function_tree (fndecl);
> -      dump_function (TDI_generic, fndecl);
>        cgraph_node::finalize_function (fndecl, false);
>      }
>
> diff --git gcc/testsuite/gcc.dg/gomp/dump-task.c gcc/testsuite/gcc.dg/gomp/dump-task.c
> new file mode 100644
> index 0000000..08ae5c3
> --- /dev/null
> +++ gcc/testsuite/gcc.dg/gomp/dump-task.c
> @@ -0,0 +1,33 @@
> +/* https://gcc.gnu.org/ml/gcc/2014-03/msg00312.html
> +   https://gcc.gnu.org/ml/gcc/2014-05/msg00117.html */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fopenmp -fdump-tree-gimple -fdump-tree-ompexp" } */
> +
> +int
> +main(void)
> +{
> +#pragma omp parallel
> +  {
> +    extern void foo(void);
> +    foo ();
> +  }
> +  return 0;
> +}
> +
> +
> +/* Check that low gimple representation does not end up in high gimple
> +   dump.  */
> +/* { dg-final { scan-tree-dump-not "main._omp_fn.0" "gimple" } } */
> +
> +/* Check for 3 references in ompexp dump: new function notification, function
> +   dump and reference in main.  */
> +/* { dg-final { scan-tree-dump-times "main._omp_fn.0" 3 "ompexp" } } */
> +
> +/* Check for function dump of main._omp_fn.0.  */
> +/* { dg-final { scan-tree-dump-times "main._omp_fn.0 \\(void" 1 "ompexp" } } */
> +
> +/* Check for presence of function body of main._omp_fn.0.  */
> +/* { dg-final { scan-tree-dump-times "foo \\(\\)" 1 "ompexp" } } */
> +
> +/* { dg-final { cleanup-tree-dump "gimple" } } */
> +/* { dg-final { cleanup-tree-dump "ompexp" } } */
>
>
> Grüße,
>  Thomas