[PATCH] Fix x86 #pragma GCC target and target attribute handling (PR target/61925)

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

This patch rewrites the target pragma and target attribute handling in the
i386 backend, so that outside of functions global_options and target globals
reflect the currently active #pragma GCC target (if none active, obviously
the default options) and inside of functions (in between set_cfun to that
function and set_cfun to another function or NULL) the target state of the
function.

Without this patch, that state often was wherever last set_cfun left it
(consider e.g. function with target attribute inside of #pragma GCC target
region), and furthermore #pragma GCC target without any function definition
before #pragma GCC pop_options confused it altogether, plus there has been
confusion between when should be the default options active and when should
be the currently active #pragma GCC target activated.

The last hunk in i386.c also attempts to save some compile time cycles, I
think it is pointless to add currently active #pragma GCC target as
attributes to all the target builtins that are activated in the call,
we certainly don't do that e.g. for target attribute.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2015-01-28  Jakub Jelinek  <jakub@redhat.com>

	PR target/61925
	* config/i386/i386.c (ix86_reset_to_default_globals): Removed.
	(ix86_reset_previous_fndecl): Restore it here, unconditionally.
	(ix86_set_current_function): Rewritten.
	(ix86_add_new_builtins): Temporarily clear current_target_pragma
	when creating builtin fndecls.

	* gcc.target/i386/pr61925-1.c: New test.
	* gcc.target/i386/pr61925-2.c: New test.
	* gcc.target/i386/pr61925-3.c: New test.

--- gcc/config/i386/i386.c.jj	2015-01-26 22:27:20.000000000 +0100
+++ gcc/config/i386/i386.c	2015-01-28 14:41:03.008727087 +0100
@@ -5076,35 +5076,20 @@ ix86_can_inline_p (tree caller, tree cal
 /* Remember the last target of ix86_set_current_function.  */
 static GTY(()) tree ix86_previous_fndecl;
 
-/* Set target globals to default.  */
+/* Set targets globals to the default (or current #pragma GCC target
+   if active).  Invalidate ix86_previous_fndecl cache.  */
 
-static void
-ix86_reset_to_default_globals (void)
-{
-  tree old_tree = (ix86_previous_fndecl
-		   ? DECL_FUNCTION_SPECIFIC_TARGET (ix86_previous_fndecl)
-		   : NULL_TREE);
-
-  if (old_tree)
-    {
-      tree new_tree = target_option_current_node;
-      cl_target_option_restore (&global_options,
-				TREE_TARGET_OPTION (new_tree));
-      if (TREE_TARGET_GLOBALS (new_tree))
-	restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
-      else if (new_tree == target_option_default_node)
-	restore_target_globals (&default_target_globals);
-      else
-	TREE_TARGET_GLOBALS (new_tree)
-	  = save_target_globals_default_opts ();
-    }
-}
-
-/* Invalidate ix86_previous_fndecl cache.  */
 void
 ix86_reset_previous_fndecl (void)
 {
-  ix86_reset_to_default_globals ();
+  tree new_tree = target_option_current_node;
+  cl_target_option_restore (&global_options, TREE_TARGET_OPTION (new_tree));
+  if (TREE_TARGET_GLOBALS (new_tree))
+    restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
+  else if (new_tree == target_option_default_node)
+    restore_target_globals (&default_target_globals);
+  else
+    TREE_TARGET_GLOBALS (new_tree) = save_target_globals_default_opts ();
   ix86_previous_fndecl = NULL_TREE;
 }
 
@@ -5117,34 +5102,39 @@ ix86_set_current_function (tree fndecl)
   /* Only change the context if the function changes.  This hook is called
      several times in the course of compiling a function, and we don't want to
      slow things down too much or call target_reinit when it isn't safe.  */
-  if (fndecl && fndecl != ix86_previous_fndecl)
-    {
-      tree old_tree = (ix86_previous_fndecl
-		       ? DECL_FUNCTION_SPECIFIC_TARGET (ix86_previous_fndecl)
-		       : NULL_TREE);
+  if (fndecl == ix86_previous_fndecl)
+    return;
 
-      tree new_tree = (fndecl
-		       ? DECL_FUNCTION_SPECIFIC_TARGET (fndecl)
-		       : NULL_TREE);
+  tree old_tree;
+  if (ix86_previous_fndecl == NULL_TREE)
+    old_tree = target_option_current_node;
+  else if (DECL_FUNCTION_SPECIFIC_TARGET (ix86_previous_fndecl))
+    old_tree = DECL_FUNCTION_SPECIFIC_TARGET (ix86_previous_fndecl);
+  else
+    old_tree = target_option_default_node;
 
-      if (old_tree == new_tree)
-	;
+  if (fndecl == NULL_TREE)
+    {
+      if (old_tree != target_option_current_node)
+	ix86_reset_previous_fndecl ();
+      return;
+    }
 
-      else if (new_tree && new_tree != target_option_default_node)
-	{
-	  cl_target_option_restore (&global_options,
-				    TREE_TARGET_OPTION (new_tree));
-	  if (TREE_TARGET_GLOBALS (new_tree))
-	    restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
-	  else
-	    TREE_TARGET_GLOBALS (new_tree)
-	      = save_target_globals_default_opts ();
-	}
+  tree new_tree = DECL_FUNCTION_SPECIFIC_TARGET (fndecl);
+  if (new_tree == NULL_TREE)
+    new_tree = target_option_default_node;
 
-      else if (old_tree && old_tree != target_option_default_node)
-	ix86_reset_to_default_globals ();
-      ix86_previous_fndecl = fndecl;
+  if (old_tree != new_tree)
+    {
+      cl_target_option_restore (&global_options, TREE_TARGET_OPTION (new_tree));
+      if (TREE_TARGET_GLOBALS (new_tree))
+	restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
+      else if (new_tree == target_option_default_node)
+	restore_target_globals (&default_target_globals);
+      else
+	TREE_TARGET_GLOBALS (new_tree) = save_target_globals_default_opts ();
     }
+  ix86_previous_fndecl = fndecl;
 }
 
 
@@ -30580,6 +30570,8 @@ static void
 ix86_add_new_builtins (HOST_WIDE_INT isa)
 {
   int i;
+  tree saved_current_target_pragma = current_target_pragma;
+  current_target_pragma = NULL_TREE;
 
   for (i = 0; i < (int)IX86_BUILTIN_MAX; i++)
     {
@@ -30606,6 +30598,8 @@ ix86_add_new_builtins (HOST_WIDE_INT isa
 	    TREE_NOTHROW (decl) = 1;
 	}
     }
+
+  current_target_pragma = saved_current_target_pragma;
 }
 
 /* Bits for builtin_description.flag.  */
--- gcc/testsuite/gcc.target/i386/pr61925-1.c.jj	2015-01-28 15:10:45.756833647 +0100
+++ gcc/testsuite/gcc.target/i386/pr61925-1.c	2015-01-28 15:11:49.911722473 +0100
@@ -0,0 +1,21 @@
+/* PR target/61925 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -w" } */
+/* { dg-additional-options "-march=i386 -mno-sse" { target ia32 } } */
+
+#pragma GCC push_options
+#pragma GCC target("sse")
+typedef float __m128 __attribute__ ((__vector_size__ (16), __may_alias__));
+typedef long long __m128i __attribute__ ((__vector_size__ (16), __may_alias__));
+__m128i
+bar (__m128 __A)
+{
+}
+
+#pragma GCC pop_options
+
+__attribute__ ((vector_size (16))) int
+foo (__attribute__ ((vector_size (16))) int a, __attribute__ ((vector_size (16))) int b)
+{
+  return a + b;
+}
--- gcc/testsuite/gcc.target/i386/pr61925-2.c.jj	2015-01-28 15:10:48.651783506 +0100
+++ gcc/testsuite/gcc.target/i386/pr61925-2.c	2015-01-28 15:11:55.432626851 +0100
@@ -0,0 +1,21 @@
+/* PR target/61925 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -w" } */
+/* { dg-additional-options "-march=i386 -mno-sse" { target ia32 } } */
+
+#pragma GCC push_options
+#pragma GCC target("sse")
+typedef float __m128 __attribute__ ((__vector_size__ (16), __may_alias__));
+extern __inline __m128 __attribute__ ((__gnu_inline__, __always_inline__, __artificial__))
+foo (void)
+{
+}
+
+#pragma GCC target("sse2")
+#pragma GCC pop_options
+
+__attribute__ ((vector_size (16))) int
+bar (__attribute__ ((vector_size (16))) int a, __attribute__ ((vector_size (16))) int b)
+{
+  return a + b;
+}
--- gcc/testsuite/gcc.target/i386/pr61925-3.c.jj	2015-01-28 15:10:51.538733503 +0100
+++ gcc/testsuite/gcc.target/i386/pr61925-3.c	2015-01-28 15:12:01.316524940 +0100
@@ -0,0 +1,27 @@
+/* PR target/61925 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -w" } */
+/* { dg-additional-options "-march=i386 -mno-sse" { target ia32 } } */
+
+#pragma GCC push_options
+#pragma GCC target("sse")
+typedef float __m128 __attribute__ ((__vector_size__ (16), __may_alias__));
+
+void
+foo (void)
+{
+}
+
+__attribute__((target ("avx"))) void
+bar (void)
+{
+}
+
+#pragma GCC target("sse2")
+#pragma GCC pop_options
+
+__attribute__ ((vector_size (16))) int
+baz (__attribute__ ((vector_size (16))) int a, __attribute__ ((vector_size (16))) int b)
+{
+  return a + b;
+}

	Jakub