builtins.c (compareAndSwapInt_builtin): Use flag_use_atomic_builtins.

2009-08-12  Andrew Haley  <aph@redhat.com>

	* builtins.c (compareAndSwapInt_builtin): Use
	flag_use_atomic_builtins.
	(compareAndSwapLong_builtin): Likewise.
	(compareAndSwapObject_builtin): Likewise.
	* jvspec.c: Add flag_use_atomic_builtins.
	* gcj.texi: Likewise.
	* java-tree.h: Likewise.
	* lang.opt: Likewise.

From-SVN: r150699

gcc/java/ChangeLog

+2009-08-12  Andrew Haley  <aph@redhat.com>
+
+	* builtins.c (compareAndSwapInt_builtin): Use
+	flag_use_atomic_builtins.
+	(compareAndSwapLong_builtin): Likewise.
+	(compareAndSwapObject_builtin): Likewise.
+	* jvspec.c: Add flag_use_atomic_builtins.
+	* gcj.texi: Likewise.
+	* java-tree.h: Likewise.
+	* lang.opt: Likewise.
+
 2009-08-11  Dodji Seketeli  <dodji@redhat.com>
 
 	PR debug/40990

gcc/java/builtins.c

@@ -318,7 +318,8 @@ compareAndSwapInt_builtin (tree method_return_type ATTRIBUTE_UNUSED,
 			   tree orig_call)
 {
   enum machine_mode mode = TYPE_MODE (int_type_node);
-  if (sync_compare_and_swap[mode] != CODE_FOR_nothing)
+  if (sync_compare_and_swap[mode] != CODE_FOR_nothing
+      || flag_use_atomic_builtins)
     {
       tree addr, stmt;
       UNMARSHAL5 (orig_call);
@@ -337,7 +338,12 @@ compareAndSwapLong_builtin (tree method_return_type ATTRIBUTE_UNUSED,
 			    tree orig_call)
 {
   enum machine_mode mode = TYPE_MODE (long_type_node);
-  if (sync_compare_and_swap[mode] != CODE_FOR_nothing)
+  if (sync_compare_and_swap[mode] != CODE_FOR_nothing
+      || (GET_MODE_SIZE (mode) <= GET_MODE_SIZE (word_mode)
+	  && flag_use_atomic_builtins))
+    /* We don't trust flag_use_atomic_builtins for multi-word
+       compareAndSwap.  Some machines such as ARM have atomic libfuncs
+       but not the multi-word versions.  */
     {
       tree addr, stmt;
       UNMARSHAL5 (orig_call);
@@ -355,7 +361,8 @@ compareAndSwapObject_builtin (tree method_return_type ATTRIBUTE_UNUSED,
 			      tree orig_call)
 {
   enum machine_mode mode = TYPE_MODE (ptr_type_node);
-  if (sync_compare_and_swap[mode] != CODE_FOR_nothing)
+  if (sync_compare_and_swap[mode] != CODE_FOR_nothing
+      || flag_use_atomic_builtins)
   {
     tree addr, stmt;
     int builtin;

gcc/java/gcj.texi

@@ -607,6 +607,13 @@ On some systems it's necessary to insert inline checks whenever
 accessing an object via a reference.  On other systems you won't need
 this because null pointer accesses are caught automatically by the
 processor.
+
+@item -fuse-atomic-builtins
+On some systems, gcc can generate code for built-in atomic operations.
+Use this option to force gcj to use these builtins when compiling Java
+code.  Where this capability is present it should be automatically
+detected, so you won't usually need to use this option.
+
 @end table
 
 @c man end

gcc/java/java-tree.h

@@ -145,6 +145,9 @@ extern int flag_newer;
 /* When nonzero, call a library routine to do integer divisions. */
 extern int flag_use_divide_subroutine;
 
+/* When nonzero, use atomic builtins. */
+extern int flag_use_atomic_builtins;
+
 /* When nonzero, generate code for the Boehm GC.  */
 extern int flag_use_boehm_gc;
 

gcc/java/jvspec.c

@@ -73,6 +73,7 @@ static const char jvgenmain_spec[] =
 		   %<fclasspath* %<fCLASSPATH* %<fbootclasspath*\
 		   %<fextdirs*\
 		   %<fuse-divide-subroutine %<fno-use-divide-subroutine\
+		   %<fuse-atomic-builtins %<fno-use-atomic-builtins\
 		   %<fcheck-references %<fno-check-references\
 		   %<ffilelist-file %<fsaw-java-file %<fsource* %<ftarget*\
 		   %{f*} -fdollars-in-identifiers\

gcc/java/lang.opt

@@ -192,6 +192,10 @@ fuse-divide-subroutine
 Java Var(flag_use_divide_subroutine) Init(1)
 Call a library routine to do integer divisions
 
+fuse-atomic-builtins
+Java Var(flag_use_atomic_builtins) Init(0)
+Generate code for built-in atomic operations
+
 fbootstrap-classes
 Java Var(flag_bootstrap_classes)
 Generated should be loaded by bootstrap loader