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

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Submitter Aldy Hernandez
Date Feb. 18, 2013, 6:50 p.m.
Message ID <51227813.9070505@redhat.com>
Download mbox | patch
Permalink /patch/221449/
State New
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Comments

Aldy Hernandez - Feb. 18, 2013, 6:50 p.m.
On 02/16/13 05:19, Richard Sandiford wrote:

> Looks good to me otherwise, thanks.

Implemented all your suggestions.

>
> Sorry that SWITCHABLE_TARGETS has been so much hassle.  TBH, like Jakub
> says in the PR, I was hoping things like the optimize attribute could
> use the target_globals stuff too.  Today we just care about optabs,
> but e.g. arm.c has:
>
>    if (TARGET_THUMB1 && optimize_size)
>      {
>        /* When optimizing for size on Thumb-1, it's better not
>          to use the HI regs, because of the overhead of
>          stacking them.  */
>        for (regno = FIRST_HI_REGNUM;
> 	   regno <= LAST_HI_REGNUM; ++regno)
> 	fixed_regs[regno] = call_used_regs[regno] = 1;
>      }
>
> which affects other cached global state like IRA tables.

...
...

> So in the end I think we'll end up trying solve the same problem that
> the SWITCHABLE_TARGETS stuff was trying to solve, but this time for
> __attribute__((optimize)).

Ughhh... perhaps this can be something for 4.9, reimplementing the 
optimize attribute with the target_globals infrastructure?

Regstrapping attached patch.

OK pending tests?
PR target/52555
	* genopinit.c (raw_optab_handler): Use this_fn_optabs.
	(swap_optab_enable): Same.
	(init_all_optabs): Use argument instead of global.
	* tree.h (struct tree_optimization_option): New field
	target_optabs.
	* expr.h (init_all_optabs): Add argument to prototype.
	(TREE_OPTIMIZATION_OPTABS): New.
	(save_optabs_if_changed): Protoize.
	* optabs.h: Declare this_fn_optabs.
	* optabs.c (save_optabs_if_changed): New.
	Declare this_fn_optabs.
	(init_optabs): Add argument to init_all_optabs() call.
	* function.c (invoke_set_current_function_hook): Handle per
	function optabs.
	* function.h (struct function): New field optabs.
	* config/mips/mips.c (mips_set_mips16_mode): Handle when
	optimization_current_node has changed.
	* target-globals.h (save_target_globals_default_opts): Protoize.
	* target-globals.c (save_target_globals_default_opts): New.
c/family
	PR target/52555
	* c-common.c (handle_optimize_attribute): Call
	save_optabs_if_changed.
Jakub Jelinek - Feb. 18, 2013, 11:05 p.m.
On Mon, Feb 18, 2013 at 12:50:59PM -0600, Aldy Hernandez wrote:
> OK pending tests?

> 	PR target/52555
> 	* genopinit.c (raw_optab_handler): Use this_fn_optabs.
> 	(swap_optab_enable): Same.
> 	(init_all_optabs): Use argument instead of global.
> 	* tree.h (struct tree_optimization_option): New field
> 	target_optabs.
> 	* expr.h (init_all_optabs): Add argument to prototype.
> 	(TREE_OPTIMIZATION_OPTABS): New.
> 	(save_optabs_if_changed): Protoize.
> 	* optabs.h: Declare this_fn_optabs.
> 	* optabs.c (save_optabs_if_changed): New.
> 	Declare this_fn_optabs.
> 	(init_optabs): Add argument to init_all_optabs() call.
> 	* function.c (invoke_set_current_function_hook): Handle per
> 	function optabs.
> 	* function.h (struct function): New field optabs.
> 	* config/mips/mips.c (mips_set_mips16_mode): Handle when
> 	optimization_current_node has changed.
> 	* target-globals.h (save_target_globals_default_opts): Protoize.
> 	* target-globals.c (save_target_globals_default_opts): New.
> c/family
> 	PR target/52555
> 	* c-common.c (handle_optimize_attribute): Call
> 	save_optabs_if_changed.

Yes, thanks.

	Jakub
Steve Ellcey - Feb. 21, 2013, 11:02 p.m.
On Mon, Feb 18, 2013 at 12:50:59PM -0600, Aldy Hernandez wrote:
> OK pending tests?

>       PR target/52555
>       * genopinit.c (raw_optab_handler): Use this_fn_optabs.
>       (swap_optab_enable): Same.
>       (init_all_optabs): Use argument instead of global.
>       * tree.h (struct tree_optimization_option): New field
>       target_optabs.
>       * expr.h (init_all_optabs): Add argument to prototype.
>       (TREE_OPTIMIZATION_OPTABS): New.
>       (save_optabs_if_changed): Protoize.
>       * optabs.h: Declare this_fn_optabs.
>       * optabs.c (save_optabs_if_changed): New.
>       Declare this_fn_optabs.
>       (init_optabs): Add argument to init_all_optabs() call.
>       * function.c (invoke_set_current_function_hook): Handle per
>       function optabs.
>       * function.h (struct function): New field optabs.
>       * config/mips/mips.c (mips_set_mips16_mode): Handle when
>       optimization_current_node has changed.
>       * target-globals.h (save_target_globals_default_opts): Protoize.
>       * target-globals.c (save_target_globals_default_opts): New.
> c/family
>       PR target/52555
>       * c-common.c (handle_optimize_attribute): Call
>       save_optabs_if_changed.

Aldy,

Have you gotten any reports of problems with this patch?  It seems to be sending cc1 into an infinite
loop during the GCC testsuite for me.  I am testing the mips-mti-linux-gnu target and tests like
gcc.target/mips/call-saved-1.c are causing cc1 to suck up all my memory and swap space before the
test times out.

I will keep digging and see if I can figure out what is going on but I wanted to see if anyone else has
reported this problem.

Steve Ellcey
sellcey@imgtec.com
Aldy Hernandez - Feb. 22, 2013, 12:09 a.m.
> Have you gotten any reports of problems with this patch?  It seems to be sending cc1 into an infinite
> loop during the GCC testsuite for me.  I am testing the mips-mti-linux-gnu target and tests like
> gcc.target/mips/call-saved-1.c are causing cc1 to suck up all my memory and swap space before the
> test times out.

No, I have not.
>
> I will keep digging and see if I can figure out what is going on but I wanted to see if anyone else has
> reported this problem.
>

Feel free to open a PR and CC me on it.

Thanks.

Patch

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 1e6afaa..a1d47a6 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 (*node);
+
       /* Restore current options.  */
       cl_optimization_restore (&global_options, &cur_opts);
     }
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index b203cdd..252e828 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -16313,7 +16313,7 @@  mips_set_mips16_mode (int mips16_p)
   if (mips16_p)
     {
       if (!mips16_globals)
-	mips16_globals = save_target_globals ();
+	mips16_globals = save_target_globals_default_opts ();
       else
 	restore_target_globals (mips16_globals);
     }
diff --git a/gcc/expr.h b/gcc/expr.h
index f5063b4..15fcb47 100644
--- a/gcc/expr.h
+++ b/gcc/expr.h
@@ -718,7 +718,7 @@  extern bool split_comparison (enum rtx_code, enum machine_mode,
 /* Call this once to initialize the contents of the optabs
    appropriately for the current target machine.  */
 extern void init_optabs (void);
-extern void init_all_optabs (void);
+extern void init_all_optabs (struct target_optabs *);
 
 /* Call this to initialize an optab function entry.  */
 extern rtx init_one_libfunc (const char *);
diff --git a/gcc/function.c b/gcc/function.c
index 4ce2259..1b41cf2 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -4400,6 +4400,26 @@  invoke_set_current_function_hook (tree fndecl)
 	}
 
       targetm.set_current_function (fndecl);
+
+      if (opts == optimization_default_node)
+	this_fn_optabs = this_target_optabs;
+      else
+	{
+	  struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
+	  if (fn->optabs == NULL)
+	    {
+	      if (this_target_optabs == &default_target_optabs)
+		fn->optabs = TREE_OPTIMIZATION_OPTABS (opts);
+	      else
+		{
+		  fn->optabs = (unsigned char *)
+		    ggc_alloc_atomic (sizeof (struct target_optabs));
+		  init_all_optabs ((struct target_optabs *) fn->optabs);
+		}
+	    }
+	  this_fn_optabs = fn->optabs ? (struct target_optabs *) fn->optabs
+	                              : this_target_optabs;
+	}
     }
 }
 
diff --git a/gcc/function.h b/gcc/function.h
index 89d71e5..53e28b7 100644
--- a/gcc/function.h
+++ b/gcc/function.h
@@ -580,6 +580,9 @@  struct GTY(()) function {
      a string describing the reason for failure.  */
   const char * GTY((skip)) cannot_be_copied_reason;
 
+  /* Optabs for this function.  This is of type `struct target_optabs *'.  */
+  unsigned char *GTY ((atomic)) optabs;
+
   /* Collected bit flags.  */
 
   /* Number of units of general registers that need saving in stdarg
diff --git a/gcc/genopinit.c b/gcc/genopinit.c
index 1bb2f77..fb80717 100644
--- a/gcc/genopinit.c
+++ b/gcc/genopinit.c
@@ -422,8 +422,8 @@  main (int argc, char **argv)
     fprintf (s_file, "  { %#08x, CODE_FOR_%s },\n", p->sort_num, p->name);
   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, "void\ninit_all_optabs (struct target_optabs *optabs)\n{\n");
+  fprintf (s_file, "  bool *ena = 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");
@@ -456,7 +456,7 @@  main (int argc, char **argv)
 	   "raw_optab_handler (unsigned scode)\n"
 	   "{\n"
 	   "  int i = lookup_handler (scode);\n"
-	   "  return (i >= 0 && this_target_optabs->pat_enable[i]\n"
+	   "  return (i >= 0 && this_fn_optabs->pat_enable[i]\n"
 	   "          ? pats[i].icode : CODE_FOR_nothing);\n"
 	   "}\n\n");
 
@@ -468,8 +468,8 @@  main (int argc, char **argv)
 	   "  int i = lookup_handler (scode);\n"
 	   "  if (i >= 0)\n"
 	   "    {\n"
-	   "      bool ret = this_target_optabs->pat_enable[i];\n"
-	   "      this_target_optabs->pat_enable[i] = set;\n"
+	   "      bool ret = this_fn_optabs->pat_enable[i];\n"
+	   "      this_fn_optabs->pat_enable[i] = set;\n"
 	   "      return ret;\n"
 	   "    }\n"
 	   "  else\n"
diff --git a/gcc/optabs.c b/gcc/optabs.c
index c1dacf4..c5778d1 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -44,6 +44,7 @@  along with GCC; see the file COPYING3.  If not see
 
 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;
@@ -6150,7 +6151,7 @@  init_optabs (void)
     libfunc_hash = htab_create_ggc (10, hash_libfunc, eq_libfunc, NULL);
 
   /* Fill in the optabs with the insns we support.  */
-  init_all_optabs ();
+  init_all_optabs (this_fn_optabs);
 
   /* The ffs function operates on `int'.  Fall back on it if we do not
      have a libgcc2 function for that width.  */
@@ -6207,6 +6208,38 @@  init_optabs (void)
   targetm.init_libfuncs ();
 }
 
+/* Recompute the optabs and save them if they have changed.  */
+
+void
+save_optabs_if_changed (tree fndecl)
+{
+  /* ?? If this fails, we should temporarily restore the default
+     target first (set_cfun (NULL) ??), do the rest of this function,
+     and then restore it.  */
+  gcc_assert (this_target_optabs == &default_target_optabs);
+
+  struct target_optabs *tmp_optabs = (struct target_optabs *)
+    ggc_alloc_atomic (sizeof (struct target_optabs));
+  tree optnode = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl);
+
+  /* Generate a new set of optabs into tmp_optabs.  */
+  init_all_optabs (tmp_optabs);
+
+  /* If the optabs changed, record it.  */
+  if (memcmp (tmp_optabs, this_target_optabs, sizeof (struct target_optabs)))
+    {
+      if (TREE_OPTIMIZATION_OPTABS (optnode))
+	ggc_free (TREE_OPTIMIZATION_OPTABS (optnode));
+
+      TREE_OPTIMIZATION_OPTABS (optnode) = (unsigned char *) tmp_optabs;
+    }
+  else
+    {
+      TREE_OPTIMIZATION_OPTABS (optnode) = NULL;
+      ggc_free (tmp_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..4de4409 100644
--- a/gcc/optabs.h
+++ b/gcc/optabs.h
@@ -76,6 +76,7 @@  struct target_optabs {
 };
 
 extern struct target_optabs default_target_optabs;
+extern struct target_optabs *this_fn_optabs;
 #if SWITCHABLE_TARGET
 extern struct target_optabs *this_target_optabs;
 #else
diff --git a/gcc/target-globals.c b/gcc/target-globals.c
index 533a8e5..d72495d 100644
--- a/gcc/target-globals.c
+++ b/gcc/target-globals.c
@@ -91,4 +91,33 @@  save_target_globals (void)
   return g;
 }
 
+/* Like save_target_globals() above, but set *this_target_optabs
+   correctly when a previous function has changed
+   *this_target_optabs.  */
+
+struct target_globals *
+save_target_globals_default_opts ()
+{
+  struct target_globals *globals;
+
+  if (optimization_current_node != optimization_default_node)
+    {
+      tree opts = optimization_current_node;
+      /* Temporarily switch to the default optimization node, so that
+	 *this_target_optabs is set to the default, not reflecting
+	 whatever a previous function used for the optimize
+	 attribute.  */
+      optimization_current_node = optimization_default_node;
+      cl_optimization_restore
+	(&global_options,
+	 TREE_OPTIMIZATION (optimization_default_node));
+      globals = save_target_globals ();
+      optimization_current_node = opts;
+      cl_optimization_restore (&global_options,
+			       TREE_OPTIMIZATION (opts));
+      return globals;
+    }
+  return save_target_globals ();
+}
+
 #endif
diff --git a/gcc/target-globals.h b/gcc/target-globals.h
index 110f879..04eba53 100644
--- a/gcc/target-globals.h
+++ b/gcc/target-globals.h
@@ -60,6 +60,7 @@  struct GTY(()) target_globals {
 extern struct target_globals default_target_globals;
 
 extern struct target_globals *save_target_globals (void);
+extern struct target_globals *save_target_globals_default_opts (void);
 
 static inline void
 restore_target_globals (struct target_globals *g)
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..740d438 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 *'.  */
+  unsigned char *GTY ((atomic)) 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 {