Patchwork PR target/52555: attribute optimize is overriding command line options

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Submitter Aldy Hernandez
Date Feb. 12, 2013, 5:28 p.m.
Message ID <511A7BBF.1030401@redhat.com>
Download mbox | patch
Permalink /patch/219918/
State New
Headers show

Comments

Aldy Hernandez - Feb. 12, 2013, 5:28 p.m.
> Rather than:
>
> 	  /* Change optabs if needed.  */
> 	  if (TREE_OPTIMIZATION_OPTABS (opts))
> 	    this_target_optabs
> 	      = (struct target_optabs *) TREE_OPTIMIZATION_OPTABS (opts);
> 	  else
> 	    this_target_optabs = &default_target_optabs;
>
> I think it'd be better to have:
>
> 	  /* Change optabs if needed.  */
> 	  if (TREE_OPTIMIZATION_OPTABS (opts))
> 	    this_fn_optabs
> 	      = (struct target_optabs *) TREE_OPTIMIZATION_OPTABS (opts);
> 	  else
> 	    this_fn_optabs = this_target_optabs;
>
> with genopinit.c updated to use this_fn_optabs instead of this_target_optabs.

Hmmm, ok.

I also added a default case setting this_fn_optabs = 
&default_target_optabs when the optimizations haven't changed.  I can 
remove this if redundant.

Jakub also recommended bailing if TREE_OPTIMIZATION_OPTABS already set, 
thus avoiding recomputing init_all_optabs() in save_optabs_if_changed:

+ if (TREE_OPTIMIZATION_OPTABS (optnode))
+    return;

Is this still part of the plan?

How is this revision?
commit 48c1f4d243f81ca975b2aae34773b91ef6cbd8ca
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Mon Feb 11 15:51:24 2013 -0600

    	PR target/52555
    	* genopinit.c (main): Use this_fn_optabs in generated
    	init_all_optabs.
    	* tree.h (struct tree_optimization_option): New field
    	target_optabs.
    	(TREE_OPTIMIZATION_OPTABS): New.
    	(save_optabs_if_changed): Protoize.
    	* optabs.h: Always declare this_target_optabs.
    	Declare this_fn_optabs.
    	* optabs.c (save_optabs_if_changed): New.
    	Always declare this_target_optabs.
    	Declare this_fn_optabs.
    	* function.c (invoke_set_current_function_hook): Set
    	this_fn_optabs if there is one in the optimization node.
    c-family/
    	* c-common.c (handle_optimize_attribute): Call
    	save_optabs_if_changed.
Richard Sandiford - Feb. 12, 2013, 5:40 p.m.
Aldy Hernandez <aldyh@redhat.com> writes:
>> Rather than:
>>
>> 	  /* Change optabs if needed.  */
>> 	  if (TREE_OPTIMIZATION_OPTABS (opts))
>> 	    this_target_optabs
>> 	      = (struct target_optabs *) TREE_OPTIMIZATION_OPTABS (opts);
>> 	  else
>> 	    this_target_optabs = &default_target_optabs;
>>
>> I think it'd be better to have:
>>
>> 	  /* Change optabs if needed.  */
>> 	  if (TREE_OPTIMIZATION_OPTABS (opts))
>> 	    this_fn_optabs
>> 	      = (struct target_optabs *) TREE_OPTIMIZATION_OPTABS (opts);
>> 	  else
>> 	    this_fn_optabs = this_target_optabs;
>>
>> with genopinit.c updated to use this_fn_optabs instead of this_target_optabs.
>
> Hmmm, ok.
>
> I also added a default case setting this_fn_optabs = 
> &default_target_optabs when the optimizations haven't changed.  I can 
> remove this if redundant.

No, sounds like a good plan, but I think it should be this_target_optabs
rather than &default_target_optabs.  Also:

@@ -76,11 +76,8 @@ struct target_optabs {
 };
 
 extern struct target_optabs default_target_optabs;
-#if SWITCHABLE_TARGET
 extern struct target_optabs *this_target_optabs;
-#else
-#define this_target_optabs (&default_target_optabs)
-#endif

This shouldn't be needed now, and:

@@ -44,8 +44,9 @@ along with GCC; see the file COPYING3.  If not see
 
 struct target_optabs default_target_optabs;
 struct target_libfuncs default_target_libfuncs;
-#if SWITCHABLE_TARGET
 struct target_optabs *this_target_optabs = &default_target_optabs;
+struct target_optabs *this_fn_optabs = &default_target_optabs;
+#if SWITCHABLE_TARGET
 struct target_libfuncs *this_target_libfuncs = &default_target_libfuncs;
 #endif

I think this should be:

 struct target_optabs default_target_optabs;
 struct target_libfuncs default_target_libfuncs;
+struct target_optabs *this_fn_optabs = &default_target_optabs;
 #if SWITCHABLE_TARGET
 struct target_optabs *this_target_optabs = &default_target_optabs;
 struct target_libfuncs *this_target_libfuncs = &default_target_libfuncs;
 #endif

Looks good to me otherwise as far as switchable targets go.

Richard
Richard Sandiford - Feb. 12, 2013, 5:45 p.m.
Richard Sandiford <rdsandiford@googlemail.com> writes:
> Aldy Hernandez <aldyh@redhat.com> writes:
>>> Rather than:
>>>
>>> 	  /* Change optabs if needed.  */
>>> 	  if (TREE_OPTIMIZATION_OPTABS (opts))
>>> 	    this_target_optabs
>>> 	      = (struct target_optabs *) TREE_OPTIMIZATION_OPTABS (opts);
>>> 	  else
>>> 	    this_target_optabs = &default_target_optabs;
>>>
>>> I think it'd be better to have:
>>>
>>> 	  /* Change optabs if needed.  */
>>> 	  if (TREE_OPTIMIZATION_OPTABS (opts))
>>> 	    this_fn_optabs
>>> 	      = (struct target_optabs *) TREE_OPTIMIZATION_OPTABS (opts);
>>> 	  else
>>> 	    this_fn_optabs = this_target_optabs;
>>>
>>> with genopinit.c updated to use this_fn_optabs instead of this_target_optabs.
>>
>> Hmmm, ok.
>>
>> I also added a default case setting this_fn_optabs = 
>> &default_target_optabs when the optimizations haven't changed.  I can 
>> remove this if redundant.
>
> No, sounds like a good plan, but I think it should be this_target_optabs
> rather than &default_target_optabs.

Gah, just realised after sending that it would be better to have:

static void
invoke_set_current_function_hook (tree fndecl)
{
  this_fn_optabs = this_target_optabs;
  if (!in_dummy_function)
    {
      tree opts = ((fndecl)
		   ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
		   : optimization_default_node);

      if (!opts)
	opts = optimization_default_node;

      /* Change optimization options if needed.  */
      if (optimization_current_node != opts)
	{
	  optimization_current_node = opts;
	  cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));

	  /* Change optabs if needed.  */
	  if (TREE_OPTIMIZATION_OPTABS (opts))
	    this_fn_optabs
	      = (struct target_optabs *) TREE_OPTIMIZATION_OPTABS (opts);
	}

      targetm.set_current_function (fndecl);
    }
}

Richard

Patch

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 1e6afaa..3711e69 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -8925,6 +8925,8 @@  handle_optimize_attribute (tree *node, tree name, tree args,
       DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)
 	= build_optimization_node ();
 
+      save_optabs_if_changed (DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node));
+
       /* Restore current options.  */
       cl_optimization_restore (&global_options, &cur_opts);
     }
diff --git a/gcc/function.c b/gcc/function.c
index 4ce2259..b177a98 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -4397,7 +4397,16 @@  invoke_set_current_function_hook (tree fndecl)
 	{
 	  optimization_current_node = opts;
 	  cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
+
+	  /* Change optabs if needed.  */
+	  if (TREE_OPTIMIZATION_OPTABS (opts))
+	    this_fn_optabs
+	      = (struct target_optabs *) TREE_OPTIMIZATION_OPTABS (opts);
+	  else
+	    this_fn_optabs = this_target_optabs;
 	}
+      else
+	this_fn_optabs = &default_target_optabs;
 
       targetm.set_current_function (fndecl);
     }
diff --git a/gcc/genopinit.c b/gcc/genopinit.c
index 1bb2f77..2a4b3e2 100644
--- a/gcc/genopinit.c
+++ b/gcc/genopinit.c
@@ -423,7 +423,7 @@  main (int argc, char **argv)
   fprintf (s_file, "};\n\n");
 
   fprintf (s_file, "void\ninit_all_optabs (void)\n{\n");
-  fprintf (s_file, "  bool *ena = this_target_optabs->pat_enable;\n");
+  fprintf (s_file, "  bool *ena = this_fn_optabs->pat_enable;\n");
   for (i = 0; patterns.iterate (i, &p); ++i)
     fprintf (s_file, "  ena[%u] = HAVE_%s;\n", i, p->name);
   fprintf (s_file, "}\n\n");
diff --git a/gcc/optabs.c b/gcc/optabs.c
index c1dacf4..e40bb5f 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -44,8 +44,9 @@  along with GCC; see the file COPYING3.  If not see
 
 struct target_optabs default_target_optabs;
 struct target_libfuncs default_target_libfuncs;
-#if SWITCHABLE_TARGET
 struct target_optabs *this_target_optabs = &default_target_optabs;
+struct target_optabs *this_fn_optabs = &default_target_optabs;
+#if SWITCHABLE_TARGET
 struct target_libfuncs *this_target_libfuncs = &default_target_libfuncs;
 #endif
 
@@ -6207,6 +6208,40 @@  init_optabs (void)
   targetm.init_libfuncs ();
 }
 
+/* Recompute the optabs.  If they have changed, save the new set of
+   optabs in the optimization node OPTNODE.  */
+
+void
+save_optabs_if_changed (tree optnode)
+{
+  struct target_optabs *save_target_optabs = this_target_optabs;
+  struct target_optabs *tmp_target_optabs = XCNEW (struct target_optabs);
+
+  /* Generate a new set of optabs into tmp_target_optabs.  */
+  this_target_optabs = tmp_target_optabs;
+  init_all_optabs ();
+  this_target_optabs = save_target_optabs;
+
+  /* If the optabs changed, record it in the node.  */
+  if (memcmp (tmp_target_optabs, &default_target_optabs,
+	      sizeof (struct target_optabs)))
+    {
+      /* ?? An existing entry in TREE_OPTIMIZATION_OPTABS indicates
+	 multiple ((optimize)) attributes for the same function.  Is
+	 this even valid?  For now, just clobber the existing entry
+	 with the new optabs.  */
+      if (TREE_OPTIMIZATION_OPTABS (optnode))
+	XDELETE (TREE_OPTIMIZATION_OPTABS (optnode));
+
+      TREE_OPTIMIZATION_OPTABS (optnode) = tmp_target_optabs;
+    }
+  else
+    {
+      TREE_OPTIMIZATION_OPTABS (optnode) = NULL;
+      XDELETE (tmp_target_optabs);
+    }
+}
+
 /* A helper function for init_sync_libfuncs.  Using the basename BASE,
    install libfuncs into TAB for BASE_N for 1 <= N <= MAX.  */
 
diff --git a/gcc/optabs.h b/gcc/optabs.h
index c08adcf..49908d4 100644
--- a/gcc/optabs.h
+++ b/gcc/optabs.h
@@ -76,11 +76,8 @@  struct target_optabs {
 };
 
 extern struct target_optabs default_target_optabs;
-#if SWITCHABLE_TARGET
 extern struct target_optabs *this_target_optabs;
-#else
-#define this_target_optabs (&default_target_optabs)
-#endif
+extern struct target_optabs *this_fn_optabs;
 
 /* Define functions given in optabs.c.  */
 
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr52555.c b/gcc/testsuite/gcc.c-torture/compile/pr52555.c
new file mode 100644
index 0000000..7016834
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr52555.c
@@ -0,0 +1,10 @@ 
+/* { dg-options "-ffast-math" } */
+
+float farg;
+unsigned val;
+
+void __attribute__((optimize("O")))
+test()
+{
+  val = __builtin_ceilf(farg);
+}
diff --git a/gcc/tree.h b/gcc/tree.h
index c3c814c..eddbca8 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3586,14 +3586,25 @@  struct GTY(()) tree_optimization_option {
 
   /* The optimization options used by the user.  */
   struct cl_optimization opts;
+
+  /* Target optabs for this set of optimization options.  This is of
+     type `struct target_optabs *'.  */
+  void *GTY ((skip)) target_optabs;
 };
 
 #define TREE_OPTIMIZATION(NODE) \
   (&OPTIMIZATION_NODE_CHECK (NODE)->optimization.opts)
 
+#define TREE_OPTIMIZATION_OPTABS(NODE) \
+  (OPTIMIZATION_NODE_CHECK (NODE)->optimization.target_optabs)
+
 /* Return a tree node that encapsulates the current optimization options.  */
 extern tree build_optimization_node (void);
 
+/* Save a new set of target_optabs in a TREE_OPTIMIZATION node if the
+   current set of optabs has changed.  */
+extern void save_optabs_if_changed (tree);
+
 /* Target options used by a function.  */
 
 struct GTY(()) tree_target_option {