Re: [PATCH, Fortran, PR 57987] Do not call cgraph_finalize_function multiple times on finalizers

Re: [PATCH, Fortran, PR 57987] Do not call cgraph_finalize_function multiple times on finalizers

[Dominique Dhumieres]

Hi Martin,

I have applied the patch on top of r201441 and I still get the warning for
gcc/testsuite/gfortran.dg/class_48.f90 with -m32 -O(2|s):

/opt/gcc/work/gcc/testsuite/gfortran.dg/class_48.f90: In function '__final_test2_T.2136.constprop.0':
/opt/gcc/work/gcc/testsuite/gfortran.dg/class_48.f90:39:0: warning: iteration 2147483648 invokes undefined behavior [-Waggressive-loop-optimizations]
     class(t), allocatable :: a
 ^
/opt/gcc/work/gcc/testsuite/gfortran.dg/class_48.f90:39:0: note: containing loop

The test gcc/testsuite/gfortran.dg/pr57987.f90 passes.

Dominique

Re: [PATCH, Fortran, PR 57987] Do not call cgraph_finalize_function multiple times on finalizers

[Martin Jambor]

Hi,

On Sat, Aug 03, 2013 at 01:12:41PM +0200, Dominique Dhumieres wrote:
> Hi Martin,
> 
> I have applied the patch on top of r201441 and I still get the warning for
> gcc/testsuite/gfortran.dg/class_48.f90 with -m32 -O(2|s):
> 
> /opt/gcc/work/gcc/testsuite/gfortran.dg/class_48.f90: In function '__final_test2_T.2136.constprop.0':
> /opt/gcc/work/gcc/testsuite/gfortran.dg/class_48.f90:39:0: warning: iteration 2147483648 invokes undefined behavior [-Waggressive-loop-optimizations]
>      class(t), allocatable :: a
>  ^
> /opt/gcc/work/gcc/testsuite/gfortran.dg/class_48.f90:39:0: note: containing loop
> 
> The test gcc/testsuite/gfortran.dg/pr57987.f90 passes.

Well, that is because this patch is a fix for PR 57987 (Fortran
finalizers considered extern-inline by middle-end) and not for PR
57904 (the incorrect warning), even though the testcase is the same.

As I pointed out, the warning happens in dead code (that is dead
thanks to IPA-CP but not removed yet when the warning is emitted).  I
have not given much thought to fixing this problem and worked on other
things.  IIRC I dug out of history that Jakub added the warning code
recently and so I CCed him.  I suppose he will have a look at this
once he re-appears.

Thanks for testing,

Martin

Re: [PATCH, Fortran, PR 57987] Do not call cgraph_finalize_function multiple times on finalizers

[Jan Hubicka]

> Hi,
> 
> when looking at another PR, I found out that inliner refused to even
> consider __final_test2_T/0 because, according to the dump, "redefined
> extern inline functions are not considered for inlining."  When I
> looked at why, I realized that the function is "finalized" (by
> cgraph_finalize_function) twice.  Once directly from front-end and
> second time from un-nesting nested functions.
> 
> This patch makes sure that the Fortran front-end does not do that.
> Some details about the patch development over the time is in bugzilla.
> Bootstrapped and tested on x86_64-linux without any problems, OK for
> trunk?

OK (I hope that the fortran part is cgraph centric so I can approve it), thanks.
Thanks for noticing it - those missed inlines seems quite unforutnate.
Honza

[PATCH, Fortran, PR 57987] Do not call cgraph_finalize_function multiple times on finalizers

[Martin Jambor]

Hi,

when looking at another PR, I found out that inliner refused to even
consider __final_test2_T/0 because, according to the dump, "redefined
extern inline functions are not considered for inlining."  When I
looked at why, I realized that the function is "finalized" (by
cgraph_finalize_function) twice.  Once directly from front-end and
second time from un-nesting nested functions.

This patch makes sure that the Fortran front-end does not do that.
Some details about the patch development over the time is in bugzilla.
Bootstrapped and tested on x86_64-linux without any problems, OK for
trunk?

Thanks,

Martin


2013-08-01  Martin Jambor  <mjambor@suse.cz>

	* cgraphunit.c (cgraph_finalize_function): Assert that nested function
	is not re-finalized.  Rename second parameter to no_collect.

fortran/
	* trans-decl.c (gfc_generate_function_code): Never call
	cgraph_finalize_function on nested functions.

testsuite/
	* gfortran.dg/pr57987.f90: New test.

Index: src/gcc/cgraphunit.c
===================================================================
--- src.orig/gcc/cgraphunit.c
+++ src/gcc/cgraphunit.c
@@ -405,17 +405,20 @@ referred_to_p (symtab_node node)
 }
 
 /* DECL has been parsed.  Take it, queue it, compile it at the whim of the
-   logic in effect.  If NESTED is true, then our caller cannot stand to have
+   logic in effect.  If NO_COLLECT is true, then our caller cannot stand to have
    the garbage collector run at the moment.  We would need to either create
    a new GC context, or just not compile right now.  */
 
 void
-cgraph_finalize_function (tree decl, bool nested)
+cgraph_finalize_function (tree decl, bool no_collect)
 {
   struct cgraph_node *node = cgraph_get_create_node (decl);
 
   if (node->symbol.definition)
     {
+      /* Nested functions should only be defined once.  */
+      gcc_assert (!DECL_CONTEXT (decl)
+		  || TREE_CODE (DECL_CONTEXT (decl)) !=	FUNCTION_DECL);
       cgraph_reset_node (node);
       node->local.redefined_extern_inline = true;
     }
@@ -454,7 +457,7 @@ cgraph_finalize_function (tree decl, boo
   if (warn_unused_parameter)
     do_warn_unused_parameter (decl);
 
-  if (!nested)
+  if (!no_collect)
     ggc_collect ();
 
   if (cgraph_state == CGRAPH_STATE_CONSTRUCTION
Index: src/gcc/fortran/trans-decl.c
===================================================================
--- src.orig/gcc/fortran/trans-decl.c
+++ src/gcc/fortran/trans-decl.c
@@ -5640,14 +5640,16 @@ gfc_generate_function_code (gfc_namespac
     }
   current_function_decl = old_context;
 
-  if (decl_function_context (fndecl) && gfc_option.coarray != GFC_FCOARRAY_LIB
-      && has_coarray_vars)
-    /* Register this function with cgraph just far enough to get it
-       added to our parent's nested function list.
-       If there are static coarrays in this function, the nested _caf_init
-       function has already called cgraph_create_node, which also created
-       the cgraph node for this function.  */
-    (void) cgraph_create_node (fndecl);
+  if (decl_function_context (fndecl))
+    {
+      /* Register this function with cgraph just far enough to get it
+	 added to our parent's nested function list.
+	 If there are static coarrays in this function, the nested _caf_init
+	 function has already called cgraph_create_node, which also created
+	 the cgraph node for this function.  */
+      if (!has_coarray_vars || gfc_option.coarray != GFC_FCOARRAY_LIB)
+	(void) cgraph_create_node (fndecl);
+    }
   else
     cgraph_finalize_function (fndecl, true);
 
Index: src/gcc/testsuite/gfortran.dg/pr57987.f90
===================================================================
--- /dev/null
+++ src/gcc/testsuite/gfortran.dg/pr57987.f90
@@ -0,0 +1,24 @@
+! { dg-do compile }
+! { dg-options "-O3 -fno-ipa-cp -fdump-ipa-inline" }
+
+program test
+  call test2 ()
+contains
+  subroutine test2 ()
+    type t
+      integer, allocatable :: x
+    end type t
+
+    type t2
+      class(t), allocatable :: a
+    end type t2
+
+    type(t2) :: one, two
+
+    allocate (two%a)
+    one = two
+  end subroutine test2
+end program test
+
+! { dg-final { scan-ipa-dump-not "redefined extern inline functions are not considered for inlining" "inline" } }
+! { dg-final { cleanup-ipa-dump "inline" } }