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* [PATCH] Do not allow to inline ifunc resolvers (PR ipa/81128).
@ 2017-06-27 12:50 Martin Liška
  2017-06-27 14:57 ` Jan Hubicka
  0 siblings, 1 reply; 5+ messages in thread
From: Martin Liška @ 2017-06-27 12:50 UTC (permalink / raw)
  To: gcc-patches; +Cc: Jan Hubicka, Nathan Sidwell

[-- Attachment #1: Type: text/plain, Size: 1133 bytes --]

Hello.

Currently ifunc is interpreted as normal alias by IPA optimizations. That's problematic
as should not consider ifunc alias as candidate for inlining, or redirection.

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
And survives MVC tests on x86_64-linux-gnu.

Ready to be installed?
Martin

gcc/ChangeLog:

2017-06-22  Martin Liska  <mliska@suse.cz>

	* ipa-inline.c (can_inline_edge_p): Return false for ifunc fns.
	* ipa-visibility.c (can_replace_by_local_alias): Likewise.

gcc/c-family/ChangeLog:

2017-06-22  Martin Liska  <mliska@suse.cz>

	* c-attribs.c (handle_alias_ifunc_attribute): Append ifunc alias
	to a function declaration.

gcc/testsuite/ChangeLog:

2017-06-22  Martin Liska  <mliska@suse.cz>

	* gcc.target/i386/pr81128.c: New test.
---
 gcc/c-family/c-attribs.c                | 11 ++++--
 gcc/ipa-inline.c                        |  2 +
 gcc/ipa-visibility.c                    |  3 +-
 gcc/testsuite/gcc.target/i386/pr81128.c | 65 +++++++++++++++++++++++++++++++++
 4 files changed, 77 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr81128.c



[-- Attachment #2: 0001-Do-not-allow-to-inline-ifunc-resolvers-PR-ipa-81128.patch --]
[-- Type: text/x-patch, Size: 3245 bytes --]

diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index 2b6845f2cbd..626ffa1cde7 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -1846,9 +1846,14 @@ handle_alias_ifunc_attribute (bool is_alias, tree *node, tree name, tree args,
 	TREE_STATIC (decl) = 1;
 
       if (!is_alias)
-	/* ifuncs are also aliases, so set that attribute too.  */
-	DECL_ATTRIBUTES (decl)
-	  = tree_cons (get_identifier ("alias"), args, DECL_ATTRIBUTES (decl));
+	{
+	  /* ifuncs are also aliases, so set that attribute too.  */
+	  DECL_ATTRIBUTES (decl)
+	    = tree_cons (get_identifier ("alias"), args,
+			 DECL_ATTRIBUTES (decl));
+	  DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("ifunc"),
+					      NULL, DECL_ATTRIBUTES (decl));
+	}
     }
   else
     {
diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
index fb20d3723cc..588fa9c41e4 100644
--- a/gcc/ipa-inline.c
+++ b/gcc/ipa-inline.c
@@ -370,6 +370,8 @@ can_inline_edge_p (struct cgraph_edge *e, bool report,
       e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
       inlinable = false;
     }
+  else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (e->callee->decl)))
+      inlinable = false;
   /* Check if caller growth allows the inlining.  */
   else if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
 	   && !disregard_limits
diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
index d5a3ae56c46..79d05b41085 100644
--- a/gcc/ipa-visibility.c
+++ b/gcc/ipa-visibility.c
@@ -345,7 +345,8 @@ can_replace_by_local_alias (symtab_node *node)
   
   return (node->get_availability () > AVAIL_INTERPOSABLE
 	  && !decl_binds_to_current_def_p (node->decl)
-	  && !node->can_be_discarded_p ());
+	  && !node->can_be_discarded_p ()
+	  && !lookup_attribute ("ifunc", DECL_ATTRIBUTES (node->decl)));
 }
 
 /* Return true if we can replace reference to NODE by local alias
diff --git a/gcc/testsuite/gcc.target/i386/pr81128.c b/gcc/testsuite/gcc.target/i386/pr81128.c
new file mode 100644
index 00000000000..90a567ad690
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr81128.c
@@ -0,0 +1,65 @@
+/* PR ipa/81128 */
+/* { dg-do run } */
+/* { dg-options "-O3" } */
+/* { dg-require-ifunc "" } */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+int resolver_fn = 0;
+int resolved_fn = 0;
+
+static inline void
+do_it_right_at_runtime_A ()
+{
+  resolved_fn++;
+}
+
+static inline void
+do_it_right_at_runtime_B ()
+{
+  resolved_fn++;
+}
+
+static inline void do_it_right_at_runtime (void);
+
+void do_it_right_at_runtime (void)
+  __attribute__ ((ifunc ("resolve_do_it_right_at_runtime")));
+
+static void (*resolve_do_it_right_at_runtime (void)) (void)
+{
+  srand (time (NULL));
+  int r = rand ();
+  resolver_fn++;
+
+  /* Use intermediate variable to get a warning for non-matching
+   * prototype. */
+  typeof(do_it_right_at_runtime) *func;
+  if (r & 1)
+    func = do_it_right_at_runtime_A;
+  else
+    func = do_it_right_at_runtime_B;
+
+  return (void *) func;
+}
+
+int
+main (void)
+{
+  const unsigned int ITERS = 10;
+
+  for (int i = ITERS; i > 0; i--)
+    {
+      do_it_right_at_runtime ();
+    }
+
+  if (resolver_fn != 1)
+    __builtin_abort ();
+
+  if (resolved_fn != 10)
+    __builtin_abort ();
+
+  return 0;
+}


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] Do not allow to inline ifunc resolvers (PR ipa/81128).
  2017-06-27 12:50 [PATCH] Do not allow to inline ifunc resolvers (PR ipa/81128) Martin Liška
@ 2017-06-27 14:57 ` Jan Hubicka
  2017-06-27 15:15   ` Martin Liška
  0 siblings, 1 reply; 5+ messages in thread
From: Jan Hubicka @ 2017-06-27 14:57 UTC (permalink / raw)
  To: Martin Liška; +Cc: gcc-patches, Nathan Sidwell

> Hello.
> 
> Currently ifunc is interpreted as normal alias by IPA optimizations. That's problematic
> as should not consider ifunc alias as candidate for inlining, or redirection.
> 
> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
> And survives MVC tests on x86_64-linux-gnu.
> 
> Ready to be installed?

Wasn't this supposed to go with arranging availability to be AVAIL_INTERPOSABLE
(as the target will be interposed by linker to the corect target)

Honza
> Martin
> 
> gcc/ChangeLog:
> 
> 2017-06-22  Martin Liska  <mliska@suse.cz>
> 
> 	* ipa-inline.c (can_inline_edge_p): Return false for ifunc fns.
> 	* ipa-visibility.c (can_replace_by_local_alias): Likewise.
> 
> gcc/c-family/ChangeLog:
> 
> 2017-06-22  Martin Liska  <mliska@suse.cz>
> 
> 	* c-attribs.c (handle_alias_ifunc_attribute): Append ifunc alias
> 	to a function declaration.
> 
> gcc/testsuite/ChangeLog:
> 
> 2017-06-22  Martin Liska  <mliska@suse.cz>
> 
> 	* gcc.target/i386/pr81128.c: New test.
> ---
>  gcc/c-family/c-attribs.c                | 11 ++++--
>  gcc/ipa-inline.c                        |  2 +
>  gcc/ipa-visibility.c                    |  3 +-
>  gcc/testsuite/gcc.target/i386/pr81128.c | 65 +++++++++++++++++++++++++++++++++
>  4 files changed, 77 insertions(+), 4 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr81128.c
> 
> 

> diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
> index 2b6845f2cbd..626ffa1cde7 100644
> --- a/gcc/c-family/c-attribs.c
> +++ b/gcc/c-family/c-attribs.c
> @@ -1846,9 +1846,14 @@ handle_alias_ifunc_attribute (bool is_alias, tree *node, tree name, tree args,
>  	TREE_STATIC (decl) = 1;
>  
>        if (!is_alias)
> -	/* ifuncs are also aliases, so set that attribute too.  */
> -	DECL_ATTRIBUTES (decl)
> -	  = tree_cons (get_identifier ("alias"), args, DECL_ATTRIBUTES (decl));
> +	{
> +	  /* ifuncs are also aliases, so set that attribute too.  */
> +	  DECL_ATTRIBUTES (decl)
> +	    = tree_cons (get_identifier ("alias"), args,
> +			 DECL_ATTRIBUTES (decl));
> +	  DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("ifunc"),
> +					      NULL, DECL_ATTRIBUTES (decl));
> +	}
>      }
>    else
>      {
> diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
> index fb20d3723cc..588fa9c41e4 100644
> --- a/gcc/ipa-inline.c
> +++ b/gcc/ipa-inline.c
> @@ -370,6 +370,8 @@ can_inline_edge_p (struct cgraph_edge *e, bool report,
>        e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
>        inlinable = false;
>      }
> +  else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (e->callee->decl)))
> +      inlinable = false;
>    /* Check if caller growth allows the inlining.  */
>    else if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
>  	   && !disregard_limits
> diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
> index d5a3ae56c46..79d05b41085 100644
> --- a/gcc/ipa-visibility.c
> +++ b/gcc/ipa-visibility.c
> @@ -345,7 +345,8 @@ can_replace_by_local_alias (symtab_node *node)
>    
>    return (node->get_availability () > AVAIL_INTERPOSABLE
>  	  && !decl_binds_to_current_def_p (node->decl)
> -	  && !node->can_be_discarded_p ());
> +	  && !node->can_be_discarded_p ()
> +	  && !lookup_attribute ("ifunc", DECL_ATTRIBUTES (node->decl)));
>  }
>  
>  /* Return true if we can replace reference to NODE by local alias
> diff --git a/gcc/testsuite/gcc.target/i386/pr81128.c b/gcc/testsuite/gcc.target/i386/pr81128.c
> new file mode 100644
> index 00000000000..90a567ad690
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr81128.c
> @@ -0,0 +1,65 @@
> +/* PR ipa/81128 */
> +/* { dg-do run } */
> +/* { dg-options "-O3" } */
> +/* { dg-require-ifunc "" } */
> +
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <time.h>
> +
> +int resolver_fn = 0;
> +int resolved_fn = 0;
> +
> +static inline void
> +do_it_right_at_runtime_A ()
> +{
> +  resolved_fn++;
> +}
> +
> +static inline void
> +do_it_right_at_runtime_B ()
> +{
> +  resolved_fn++;
> +}
> +
> +static inline void do_it_right_at_runtime (void);
> +
> +void do_it_right_at_runtime (void)
> +  __attribute__ ((ifunc ("resolve_do_it_right_at_runtime")));
> +
> +static void (*resolve_do_it_right_at_runtime (void)) (void)
> +{
> +  srand (time (NULL));
> +  int r = rand ();
> +  resolver_fn++;
> +
> +  /* Use intermediate variable to get a warning for non-matching
> +   * prototype. */
> +  typeof(do_it_right_at_runtime) *func;
> +  if (r & 1)
> +    func = do_it_right_at_runtime_A;
> +  else
> +    func = do_it_right_at_runtime_B;
> +
> +  return (void *) func;
> +}
> +
> +int
> +main (void)
> +{
> +  const unsigned int ITERS = 10;
> +
> +  for (int i = ITERS; i > 0; i--)
> +    {
> +      do_it_right_at_runtime ();
> +    }
> +
> +  if (resolver_fn != 1)
> +    __builtin_abort ();
> +
> +  if (resolved_fn != 10)
> +    __builtin_abort ();
> +
> +  return 0;
> +}
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] Do not allow to inline ifunc resolvers (PR ipa/81128).
  2017-06-27 14:57 ` Jan Hubicka
@ 2017-06-27 15:15   ` Martin Liška
  2017-06-27 15:26     ` Jan Hubicka
  0 siblings, 1 reply; 5+ messages in thread
From: Martin Liška @ 2017-06-27 15:15 UTC (permalink / raw)
  To: Jan Hubicka; +Cc: gcc-patches, Nathan Sidwell

On 06/27/2017 04:57 PM, Jan Hubicka wrote:
>> Hello.
>>
>> Currently ifunc is interpreted as normal alias by IPA optimizations. That's problematic
>> as should not consider ifunc alias as candidate for inlining, or redirection.
>>
>> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
>> And survives MVC tests on x86_64-linux-gnu.
>>
>> Ready to be installed?
> 
> Wasn't this supposed to go with arranging availability to be AVAIL_INTERPOSABLE
> (as the target will be interposed by linker to the corect target)

Should work, there's alternative patch:

diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index 2b6845f2cbd..626ffa1cde7 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -1846,9 +1846,14 @@ handle_alias_ifunc_attribute (bool is_alias, tree *node, tree name, tree args,
        TREE_STATIC (decl) = 1;
 
       if (!is_alias)
-       /* ifuncs are also aliases, so set that attribute too.  */
-       DECL_ATTRIBUTES (decl)
-         = tree_cons (get_identifier ("alias"), args, DECL_ATTRIBUTES (decl));
+       {
+         /* ifuncs are also aliases, so set that attribute too.  */
+         DECL_ATTRIBUTES (decl)
+           = tree_cons (get_identifier ("alias"), args,
+                        DECL_ATTRIBUTES (decl));
+         DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("ifunc"),
+                                             NULL, DECL_ATTRIBUTES (decl));
+       }
     }
   else
     {
diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
index d5a3ae56c46..69e6e295d55 100644
--- a/gcc/ipa-visibility.c
+++ b/gcc/ipa-visibility.c
@@ -97,7 +97,8 @@ non_local_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
           && !DECL_EXTERNAL (node->decl)
           && !node->externally_visible
           && !node->used_from_other_partition
-          && !node->in_other_partition);
+          && !node->in_other_partition
+          && !lookup_attribute ("ifunc", DECL_ATTRIBUTES (node->decl)));
 }
 
 /* Return true when function can be marked local.  */

It's questionable if local.local can be true for ifunc function? If can, one would need to
move check for ifunc aerly in:
/* Return function availability.  See cgraph.h for description of individual
   return values.  */
enum availability
cgraph_node::get_availability (symtab_node *ref)
{
  if (ref)
    {
      cgraph_node *cref = dyn_cast <cgraph_node *> (ref);
      if (cref)
	ref = cref->global.inlined_to;
    }
  enum availability avail;
  if (!analyzed)
    avail = AVAIL_NOT_AVAILABLE;
  else if (local.local)
    avail = AVAIL_LOCAL;
  else if (global.inlined_to)
    avail = AVAIL_AVAILABLE;
  else if (transparent_alias)
    ultimate_alias_target (&avail, ref);
  else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
    avail = AVAIL_INTERPOSABLE;

...

What solution do you prefer Honza?

Thanks,
Martin

> 
> Honza
>> Martin
>>
>> gcc/ChangeLog:
>>
>> 2017-06-22  Martin Liska  <mliska@suse.cz>
>>
>> 	* ipa-inline.c (can_inline_edge_p): Return false for ifunc fns.
>> 	* ipa-visibility.c (can_replace_by_local_alias): Likewise.
>>
>> gcc/c-family/ChangeLog:
>>
>> 2017-06-22  Martin Liska  <mliska@suse.cz>
>>
>> 	* c-attribs.c (handle_alias_ifunc_attribute): Append ifunc alias
>> 	to a function declaration.
>>
>> gcc/testsuite/ChangeLog:
>>
>> 2017-06-22  Martin Liska  <mliska@suse.cz>
>>
>> 	* gcc.target/i386/pr81128.c: New test.
>> ---
>>  gcc/c-family/c-attribs.c                | 11 ++++--
>>  gcc/ipa-inline.c                        |  2 +
>>  gcc/ipa-visibility.c                    |  3 +-
>>  gcc/testsuite/gcc.target/i386/pr81128.c | 65 +++++++++++++++++++++++++++++++++
>>  4 files changed, 77 insertions(+), 4 deletions(-)
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr81128.c
>>
>>
> 
>> diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
>> index 2b6845f2cbd..626ffa1cde7 100644
>> --- a/gcc/c-family/c-attribs.c
>> +++ b/gcc/c-family/c-attribs.c
>> @@ -1846,9 +1846,14 @@ handle_alias_ifunc_attribute (bool is_alias, tree *node, tree name, tree args,
>>  	TREE_STATIC (decl) = 1;
>>  
>>        if (!is_alias)
>> -	/* ifuncs are also aliases, so set that attribute too.  */
>> -	DECL_ATTRIBUTES (decl)
>> -	  = tree_cons (get_identifier ("alias"), args, DECL_ATTRIBUTES (decl));
>> +	{
>> +	  /* ifuncs are also aliases, so set that attribute too.  */
>> +	  DECL_ATTRIBUTES (decl)
>> +	    = tree_cons (get_identifier ("alias"), args,
>> +			 DECL_ATTRIBUTES (decl));
>> +	  DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("ifunc"),
>> +					      NULL, DECL_ATTRIBUTES (decl));
>> +	}
>>      }
>>    else
>>      {
>> diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
>> index fb20d3723cc..588fa9c41e4 100644
>> --- a/gcc/ipa-inline.c
>> +++ b/gcc/ipa-inline.c
>> @@ -370,6 +370,8 @@ can_inline_edge_p (struct cgraph_edge *e, bool report,
>>        e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
>>        inlinable = false;
>>      }
>> +  else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (e->callee->decl)))
>> +      inlinable = false;
>>    /* Check if caller growth allows the inlining.  */
>>    else if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
>>  	   && !disregard_limits
>> diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
>> index d5a3ae56c46..79d05b41085 100644
>> --- a/gcc/ipa-visibility.c
>> +++ b/gcc/ipa-visibility.c
>> @@ -345,7 +345,8 @@ can_replace_by_local_alias (symtab_node *node)
>>    
>>    return (node->get_availability () > AVAIL_INTERPOSABLE
>>  	  && !decl_binds_to_current_def_p (node->decl)
>> -	  && !node->can_be_discarded_p ());
>> +	  && !node->can_be_discarded_p ()
>> +	  && !lookup_attribute ("ifunc", DECL_ATTRIBUTES (node->decl)));
>>  }
>>  
>>  /* Return true if we can replace reference to NODE by local alias
>> diff --git a/gcc/testsuite/gcc.target/i386/pr81128.c b/gcc/testsuite/gcc.target/i386/pr81128.c
>> new file mode 100644
>> index 00000000000..90a567ad690
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/i386/pr81128.c
>> @@ -0,0 +1,65 @@
>> +/* PR ipa/81128 */
>> +/* { dg-do run } */
>> +/* { dg-options "-O3" } */
>> +/* { dg-require-ifunc "" } */
>> +
>> +
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <time.h>
>> +
>> +int resolver_fn = 0;
>> +int resolved_fn = 0;
>> +
>> +static inline void
>> +do_it_right_at_runtime_A ()
>> +{
>> +  resolved_fn++;
>> +}
>> +
>> +static inline void
>> +do_it_right_at_runtime_B ()
>> +{
>> +  resolved_fn++;
>> +}
>> +
>> +static inline void do_it_right_at_runtime (void);
>> +
>> +void do_it_right_at_runtime (void)
>> +  __attribute__ ((ifunc ("resolve_do_it_right_at_runtime")));
>> +
>> +static void (*resolve_do_it_right_at_runtime (void)) (void)
>> +{
>> +  srand (time (NULL));
>> +  int r = rand ();
>> +  resolver_fn++;
>> +
>> +  /* Use intermediate variable to get a warning for non-matching
>> +   * prototype. */
>> +  typeof(do_it_right_at_runtime) *func;
>> +  if (r & 1)
>> +    func = do_it_right_at_runtime_A;
>> +  else
>> +    func = do_it_right_at_runtime_B;
>> +
>> +  return (void *) func;
>> +}
>> +
>> +int
>> +main (void)
>> +{
>> +  const unsigned int ITERS = 10;
>> +
>> +  for (int i = ITERS; i > 0; i--)
>> +    {
>> +      do_it_right_at_runtime ();
>> +    }
>> +
>> +  if (resolver_fn != 1)
>> +    __builtin_abort ();
>> +
>> +  if (resolved_fn != 10)
>> +    __builtin_abort ();
>> +
>> +  return 0;
>> +}
>>
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] Do not allow to inline ifunc resolvers (PR ipa/81128).
  2017-06-27 15:15   ` Martin Liška
@ 2017-06-27 15:26     ` Jan Hubicka
  2017-06-28 12:46       ` Martin Liška
  0 siblings, 1 reply; 5+ messages in thread
From: Jan Hubicka @ 2017-06-27 15:26 UTC (permalink / raw)
  To: Martin Liška; +Cc: gcc-patches, Nathan Sidwell

> diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
> index d5a3ae56c46..69e6e295d55 100644
> --- a/gcc/ipa-visibility.c
> +++ b/gcc/ipa-visibility.c
> @@ -97,7 +97,8 @@ non_local_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
>            && !DECL_EXTERNAL (node->decl)
>            && !node->externally_visible
>            && !node->used_from_other_partition
> -          && !node->in_other_partition);
> +          && !node->in_other_partition
> +          && !lookup_attribute ("ifunc", DECL_ATTRIBUTES (node->decl)));
>  }
>  
>  /* Return true when function can be marked local.  */
> 
> It's questionable if local.local can be true for ifunc function? If can, one would need to
> move check for ifunc aerly in:
> /* Return function availability.  See cgraph.h for description of individual
>    return values.  */
> enum availability
> cgraph_node::get_availability (symtab_node *ref)
> {
>   if (ref)
>     {
>       cgraph_node *cref = dyn_cast <cgraph_node *> (ref);
>       if (cref)
> 	ref = cref->global.inlined_to;
>     }
>   enum availability avail;
>   if (!analyzed)
>     avail = AVAIL_NOT_AVAILABLE;
>   else if (local.local)
>     avail = AVAIL_LOCAL;
>   else if (global.inlined_to)
>     avail = AVAIL_AVAILABLE;
>   else if (transparent_alias)
>     ultimate_alias_target (&avail, ref);
>   else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
>     avail = AVAIL_INTERPOSABLE;
> 
> ...
> 
> What solution do you prefer Honza?

Probably just update non_local_p to also check that availability is at least AVAIL_AVAILABLE.
Then we will have one place to collect such a side cases where !EXTERNAL function can be
interposed.

Honza
> 
> Thanks,
> Martin
> 
> > 
> > Honza
> >> Martin
> >>
> >> gcc/ChangeLog:
> >>
> >> 2017-06-22  Martin Liska  <mliska@suse.cz>
> >>
> >> 	* ipa-inline.c (can_inline_edge_p): Return false for ifunc fns.
> >> 	* ipa-visibility.c (can_replace_by_local_alias): Likewise.
> >>
> >> gcc/c-family/ChangeLog:
> >>
> >> 2017-06-22  Martin Liska  <mliska@suse.cz>
> >>
> >> 	* c-attribs.c (handle_alias_ifunc_attribute): Append ifunc alias
> >> 	to a function declaration.
> >>
> >> gcc/testsuite/ChangeLog:
> >>
> >> 2017-06-22  Martin Liska  <mliska@suse.cz>
> >>
> >> 	* gcc.target/i386/pr81128.c: New test.
> >> ---
> >>  gcc/c-family/c-attribs.c                | 11 ++++--
> >>  gcc/ipa-inline.c                        |  2 +
> >>  gcc/ipa-visibility.c                    |  3 +-
> >>  gcc/testsuite/gcc.target/i386/pr81128.c | 65 +++++++++++++++++++++++++++++++++
> >>  4 files changed, 77 insertions(+), 4 deletions(-)
> >>  create mode 100644 gcc/testsuite/gcc.target/i386/pr81128.c
> >>
> >>
> > 
> >> diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
> >> index 2b6845f2cbd..626ffa1cde7 100644
> >> --- a/gcc/c-family/c-attribs.c
> >> +++ b/gcc/c-family/c-attribs.c
> >> @@ -1846,9 +1846,14 @@ handle_alias_ifunc_attribute (bool is_alias, tree *node, tree name, tree args,
> >>  	TREE_STATIC (decl) = 1;
> >>  
> >>        if (!is_alias)
> >> -	/* ifuncs are also aliases, so set that attribute too.  */
> >> -	DECL_ATTRIBUTES (decl)
> >> -	  = tree_cons (get_identifier ("alias"), args, DECL_ATTRIBUTES (decl));
> >> +	{
> >> +	  /* ifuncs are also aliases, so set that attribute too.  */
> >> +	  DECL_ATTRIBUTES (decl)
> >> +	    = tree_cons (get_identifier ("alias"), args,
> >> +			 DECL_ATTRIBUTES (decl));
> >> +	  DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("ifunc"),
> >> +					      NULL, DECL_ATTRIBUTES (decl));
> >> +	}
> >>      }
> >>    else
> >>      {
> >> diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
> >> index fb20d3723cc..588fa9c41e4 100644
> >> --- a/gcc/ipa-inline.c
> >> +++ b/gcc/ipa-inline.c
> >> @@ -370,6 +370,8 @@ can_inline_edge_p (struct cgraph_edge *e, bool report,
> >>        e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
> >>        inlinable = false;
> >>      }
> >> +  else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (e->callee->decl)))
> >> +      inlinable = false;
> >>    /* Check if caller growth allows the inlining.  */
> >>    else if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
> >>  	   && !disregard_limits
> >> diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
> >> index d5a3ae56c46..79d05b41085 100644
> >> --- a/gcc/ipa-visibility.c
> >> +++ b/gcc/ipa-visibility.c
> >> @@ -345,7 +345,8 @@ can_replace_by_local_alias (symtab_node *node)
> >>    
> >>    return (node->get_availability () > AVAIL_INTERPOSABLE
> >>  	  && !decl_binds_to_current_def_p (node->decl)
> >> -	  && !node->can_be_discarded_p ());
> >> +	  && !node->can_be_discarded_p ()
> >> +	  && !lookup_attribute ("ifunc", DECL_ATTRIBUTES (node->decl)));
> >>  }
> >>  
> >>  /* Return true if we can replace reference to NODE by local alias
> >> diff --git a/gcc/testsuite/gcc.target/i386/pr81128.c b/gcc/testsuite/gcc.target/i386/pr81128.c
> >> new file mode 100644
> >> index 00000000000..90a567ad690
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.target/i386/pr81128.c
> >> @@ -0,0 +1,65 @@
> >> +/* PR ipa/81128 */
> >> +/* { dg-do run } */
> >> +/* { dg-options "-O3" } */
> >> +/* { dg-require-ifunc "" } */
> >> +
> >> +
> >> +#include <stdio.h>
> >> +#include <stdlib.h>
> >> +#include <time.h>
> >> +
> >> +int resolver_fn = 0;
> >> +int resolved_fn = 0;
> >> +
> >> +static inline void
> >> +do_it_right_at_runtime_A ()
> >> +{
> >> +  resolved_fn++;
> >> +}
> >> +
> >> +static inline void
> >> +do_it_right_at_runtime_B ()
> >> +{
> >> +  resolved_fn++;
> >> +}
> >> +
> >> +static inline void do_it_right_at_runtime (void);
> >> +
> >> +void do_it_right_at_runtime (void)
> >> +  __attribute__ ((ifunc ("resolve_do_it_right_at_runtime")));
> >> +
> >> +static void (*resolve_do_it_right_at_runtime (void)) (void)
> >> +{
> >> +  srand (time (NULL));
> >> +  int r = rand ();
> >> +  resolver_fn++;
> >> +
> >> +  /* Use intermediate variable to get a warning for non-matching
> >> +   * prototype. */
> >> +  typeof(do_it_right_at_runtime) *func;
> >> +  if (r & 1)
> >> +    func = do_it_right_at_runtime_A;
> >> +  else
> >> +    func = do_it_right_at_runtime_B;
> >> +
> >> +  return (void *) func;
> >> +}
> >> +
> >> +int
> >> +main (void)
> >> +{
> >> +  const unsigned int ITERS = 10;
> >> +
> >> +  for (int i = ITERS; i > 0; i--)
> >> +    {
> >> +      do_it_right_at_runtime ();
> >> +    }
> >> +
> >> +  if (resolver_fn != 1)
> >> +    __builtin_abort ();
> >> +
> >> +  if (resolved_fn != 10)
> >> +    __builtin_abort ();
> >> +
> >> +  return 0;
> >> +}
> >>
> > 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] Do not allow to inline ifunc resolvers (PR ipa/81128).
  2017-06-27 15:26     ` Jan Hubicka
@ 2017-06-28 12:46       ` Martin Liška
  0 siblings, 0 replies; 5+ messages in thread
From: Martin Liška @ 2017-06-28 12:46 UTC (permalink / raw)
  To: Jan Hubicka; +Cc: gcc-patches, Nathan Sidwell

[-- Attachment #1: Type: text/plain, Size: 6699 bytes --]

On 06/27/2017 05:26 PM, Jan Hubicka wrote:
>> diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
>> index d5a3ae56c46..69e6e295d55 100644
>> --- a/gcc/ipa-visibility.c
>> +++ b/gcc/ipa-visibility.c
>> @@ -97,7 +97,8 @@ non_local_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
>>            && !DECL_EXTERNAL (node->decl)
>>            && !node->externally_visible
>>            && !node->used_from_other_partition
>> -          && !node->in_other_partition);
>> +          && !node->in_other_partition
>> +          && !lookup_attribute ("ifunc", DECL_ATTRIBUTES (node->decl)));
>>  }
>>  
>>  /* Return true when function can be marked local.  */
>>
>> It's questionable if local.local can be true for ifunc function? If can, one would need to
>> move check for ifunc aerly in:
>> /* Return function availability.  See cgraph.h for description of individual
>>    return values.  */
>> enum availability
>> cgraph_node::get_availability (symtab_node *ref)
>> {
>>   if (ref)
>>     {
>>       cgraph_node *cref = dyn_cast <cgraph_node *> (ref);
>>       if (cref)
>> 	ref = cref->global.inlined_to;
>>     }
>>   enum availability avail;
>>   if (!analyzed)
>>     avail = AVAIL_NOT_AVAILABLE;
>>   else if (local.local)
>>     avail = AVAIL_LOCAL;
>>   else if (global.inlined_to)
>>     avail = AVAIL_AVAILABLE;
>>   else if (transparent_alias)
>>     ultimate_alias_target (&avail, ref);
>>   else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
>>     avail = AVAIL_INTERPOSABLE;
>>
>> ...
>>
>> What solution do you prefer Honza?
> 
> Probably just update non_local_p to also check that availability is at least AVAIL_AVAILABLE.
> Then we will have one place to collect such a side cases where !EXTERNAL function can be
> interposed.

Good, this is tested version of patch I'm going to install.

Martin

> 
> Honza
>>
>> Thanks,
>> Martin
>>
>>>
>>> Honza
>>>> Martin
>>>>
>>>> gcc/ChangeLog:
>>>>
>>>> 2017-06-22  Martin Liska  <mliska@suse.cz>
>>>>
>>>> 	* ipa-inline.c (can_inline_edge_p): Return false for ifunc fns.
>>>> 	* ipa-visibility.c (can_replace_by_local_alias): Likewise.
>>>>
>>>> gcc/c-family/ChangeLog:
>>>>
>>>> 2017-06-22  Martin Liska  <mliska@suse.cz>
>>>>
>>>> 	* c-attribs.c (handle_alias_ifunc_attribute): Append ifunc alias
>>>> 	to a function declaration.
>>>>
>>>> gcc/testsuite/ChangeLog:
>>>>
>>>> 2017-06-22  Martin Liska  <mliska@suse.cz>
>>>>
>>>> 	* gcc.target/i386/pr81128.c: New test.
>>>> ---
>>>>  gcc/c-family/c-attribs.c                | 11 ++++--
>>>>  gcc/ipa-inline.c                        |  2 +
>>>>  gcc/ipa-visibility.c                    |  3 +-
>>>>  gcc/testsuite/gcc.target/i386/pr81128.c | 65 +++++++++++++++++++++++++++++++++
>>>>  4 files changed, 77 insertions(+), 4 deletions(-)
>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr81128.c
>>>>
>>>>
>>>
>>>> diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
>>>> index 2b6845f2cbd..626ffa1cde7 100644
>>>> --- a/gcc/c-family/c-attribs.c
>>>> +++ b/gcc/c-family/c-attribs.c
>>>> @@ -1846,9 +1846,14 @@ handle_alias_ifunc_attribute (bool is_alias, tree *node, tree name, tree args,
>>>>  	TREE_STATIC (decl) = 1;
>>>>  
>>>>        if (!is_alias)
>>>> -	/* ifuncs are also aliases, so set that attribute too.  */
>>>> -	DECL_ATTRIBUTES (decl)
>>>> -	  = tree_cons (get_identifier ("alias"), args, DECL_ATTRIBUTES (decl));
>>>> +	{
>>>> +	  /* ifuncs are also aliases, so set that attribute too.  */
>>>> +	  DECL_ATTRIBUTES (decl)
>>>> +	    = tree_cons (get_identifier ("alias"), args,
>>>> +			 DECL_ATTRIBUTES (decl));
>>>> +	  DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("ifunc"),
>>>> +					      NULL, DECL_ATTRIBUTES (decl));
>>>> +	}
>>>>      }
>>>>    else
>>>>      {
>>>> diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
>>>> index fb20d3723cc..588fa9c41e4 100644
>>>> --- a/gcc/ipa-inline.c
>>>> +++ b/gcc/ipa-inline.c
>>>> @@ -370,6 +370,8 @@ can_inline_edge_p (struct cgraph_edge *e, bool report,
>>>>        e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
>>>>        inlinable = false;
>>>>      }
>>>> +  else if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (e->callee->decl)))
>>>> +      inlinable = false;
>>>>    /* Check if caller growth allows the inlining.  */
>>>>    else if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
>>>>  	   && !disregard_limits
>>>> diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
>>>> index d5a3ae56c46..79d05b41085 100644
>>>> --- a/gcc/ipa-visibility.c
>>>> +++ b/gcc/ipa-visibility.c
>>>> @@ -345,7 +345,8 @@ can_replace_by_local_alias (symtab_node *node)
>>>>    
>>>>    return (node->get_availability () > AVAIL_INTERPOSABLE
>>>>  	  && !decl_binds_to_current_def_p (node->decl)
>>>> -	  && !node->can_be_discarded_p ());
>>>> +	  && !node->can_be_discarded_p ()
>>>> +	  && !lookup_attribute ("ifunc", DECL_ATTRIBUTES (node->decl)));
>>>>  }
>>>>  
>>>>  /* Return true if we can replace reference to NODE by local alias
>>>> diff --git a/gcc/testsuite/gcc.target/i386/pr81128.c b/gcc/testsuite/gcc.target/i386/pr81128.c
>>>> new file mode 100644
>>>> index 00000000000..90a567ad690
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.target/i386/pr81128.c
>>>> @@ -0,0 +1,65 @@
>>>> +/* PR ipa/81128 */
>>>> +/* { dg-do run } */
>>>> +/* { dg-options "-O3" } */
>>>> +/* { dg-require-ifunc "" } */
>>>> +
>>>> +
>>>> +#include <stdio.h>
>>>> +#include <stdlib.h>
>>>> +#include <time.h>
>>>> +
>>>> +int resolver_fn = 0;
>>>> +int resolved_fn = 0;
>>>> +
>>>> +static inline void
>>>> +do_it_right_at_runtime_A ()
>>>> +{
>>>> +  resolved_fn++;
>>>> +}
>>>> +
>>>> +static inline void
>>>> +do_it_right_at_runtime_B ()
>>>> +{
>>>> +  resolved_fn++;
>>>> +}
>>>> +
>>>> +static inline void do_it_right_at_runtime (void);
>>>> +
>>>> +void do_it_right_at_runtime (void)
>>>> +  __attribute__ ((ifunc ("resolve_do_it_right_at_runtime")));
>>>> +
>>>> +static void (*resolve_do_it_right_at_runtime (void)) (void)
>>>> +{
>>>> +  srand (time (NULL));
>>>> +  int r = rand ();
>>>> +  resolver_fn++;
>>>> +
>>>> +  /* Use intermediate variable to get a warning for non-matching
>>>> +   * prototype. */
>>>> +  typeof(do_it_right_at_runtime) *func;
>>>> +  if (r & 1)
>>>> +    func = do_it_right_at_runtime_A;
>>>> +  else
>>>> +    func = do_it_right_at_runtime_B;
>>>> +
>>>> +  return (void *) func;
>>>> +}
>>>> +
>>>> +int
>>>> +main (void)
>>>> +{
>>>> +  const unsigned int ITERS = 10;
>>>> +
>>>> +  for (int i = ITERS; i > 0; i--)
>>>> +    {
>>>> +      do_it_right_at_runtime ();
>>>> +    }
>>>> +
>>>> +  if (resolver_fn != 1)
>>>> +    __builtin_abort ();
>>>> +
>>>> +  if (resolved_fn != 10)
>>>> +    __builtin_abort ();
>>>> +
>>>> +  return 0;
>>>> +}
>>>>
>>>


[-- Attachment #2: 0001-Do-not-allow-to-inline-ifunc-resolvers-PR-ipa-81128.patch --]
[-- Type: text/x-patch, Size: 3617 bytes --]

From f1fcd618d424fe617cd75190d89e85941e9d7b98 Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Thu, 22 Jun 2017 09:19:31 +0200
Subject: [PATCH] Do not allow to inline ifunc resolvers (PR ipa/81128).

gcc/ChangeLog:

2017-06-22  Martin Liska  <mliska@suse.cz>

	* ipa-visibility.c (non_local_p): Handle visibility.

gcc/c-family/ChangeLog:

2017-06-22  Martin Liska  <mliska@suse.cz>

	* c-attribs.c (handle_alias_ifunc_attribute): Append ifunc alias
	to a function declaration.

gcc/testsuite/ChangeLog:

2017-06-22  Martin Liska  <mliska@suse.cz>

	* gcc.target/i386/pr81128.c: New test.
---
 gcc/c-family/c-attribs.c                | 11 ++++--
 gcc/ipa-visibility.c                    |  3 +-
 gcc/testsuite/gcc.target/i386/pr81128.c | 65 +++++++++++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr81128.c

diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index 2b6845f2cbd..626ffa1cde7 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -1846,9 +1846,14 @@ handle_alias_ifunc_attribute (bool is_alias, tree *node, tree name, tree args,
 	TREE_STATIC (decl) = 1;
 
       if (!is_alias)
-	/* ifuncs are also aliases, so set that attribute too.  */
-	DECL_ATTRIBUTES (decl)
-	  = tree_cons (get_identifier ("alias"), args, DECL_ATTRIBUTES (decl));
+	{
+	  /* ifuncs are also aliases, so set that attribute too.  */
+	  DECL_ATTRIBUTES (decl)
+	    = tree_cons (get_identifier ("alias"), args,
+			 DECL_ATTRIBUTES (decl));
+	  DECL_ATTRIBUTES (decl) = tree_cons (get_identifier ("ifunc"),
+					      NULL, DECL_ATTRIBUTES (decl));
+	}
     }
   else
     {
diff --git a/gcc/ipa-visibility.c b/gcc/ipa-visibility.c
index d5a3ae56c46..da4a22e7329 100644
--- a/gcc/ipa-visibility.c
+++ b/gcc/ipa-visibility.c
@@ -97,7 +97,8 @@ non_local_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
 	   && !DECL_EXTERNAL (node->decl)
 	   && !node->externally_visible
 	   && !node->used_from_other_partition
-	   && !node->in_other_partition);
+	   && !node->in_other_partition
+	   && node->get_availability () >= AVAIL_AVAILABLE);
 }
 
 /* Return true when function can be marked local.  */
diff --git a/gcc/testsuite/gcc.target/i386/pr81128.c b/gcc/testsuite/gcc.target/i386/pr81128.c
new file mode 100644
index 00000000000..90a567ad690
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr81128.c
@@ -0,0 +1,65 @@
+/* PR ipa/81128 */
+/* { dg-do run } */
+/* { dg-options "-O3" } */
+/* { dg-require-ifunc "" } */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+int resolver_fn = 0;
+int resolved_fn = 0;
+
+static inline void
+do_it_right_at_runtime_A ()
+{
+  resolved_fn++;
+}
+
+static inline void
+do_it_right_at_runtime_B ()
+{
+  resolved_fn++;
+}
+
+static inline void do_it_right_at_runtime (void);
+
+void do_it_right_at_runtime (void)
+  __attribute__ ((ifunc ("resolve_do_it_right_at_runtime")));
+
+static void (*resolve_do_it_right_at_runtime (void)) (void)
+{
+  srand (time (NULL));
+  int r = rand ();
+  resolver_fn++;
+
+  /* Use intermediate variable to get a warning for non-matching
+   * prototype. */
+  typeof(do_it_right_at_runtime) *func;
+  if (r & 1)
+    func = do_it_right_at_runtime_A;
+  else
+    func = do_it_right_at_runtime_B;
+
+  return (void *) func;
+}
+
+int
+main (void)
+{
+  const unsigned int ITERS = 10;
+
+  for (int i = ITERS; i > 0; i--)
+    {
+      do_it_right_at_runtime ();
+    }
+
+  if (resolver_fn != 1)
+    __builtin_abort ();
+
+  if (resolved_fn != 10)
+    __builtin_abort ();
+
+  return 0;
+}
-- 
2.13.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2017-06-28 12:46 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-06-27 12:50 [PATCH] Do not allow to inline ifunc resolvers (PR ipa/81128) Martin Liška
2017-06-27 14:57 ` Jan Hubicka
2017-06-27 15:15   ` Martin Liška
2017-06-27 15:26     ` Jan Hubicka
2017-06-28 12:46       ` Martin Liška

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