Allow libcalls to be installed for legacy __sync optabs.

This allows a target which implements the __sync interfaces
in libgcc to continue to use them transparently with the
new __atomic builtins.

It is assumed that these libgcc routines DO NOT use spinlocks.
This is true of all extant libgcc instances.

        * optabs.h (OTI_sync_compare_and_swap, OTI_sync_lock_test_and_set,
        OTI_sync_old_add, OTI_sync_old_sub, OTI_sync_old_ior,
        OTI_sync_old_and, OTI_sync_old_xor, OTI_sync_old_nand,
        OTI_sync_new_add, OTI_sync_new_sub, OTI_sync_new_ior,
        OTI_sync_new_and, OTI_sync_new_xor, OTI_sync_new_nand): Move and
        rename from the direct_optab_index enum.
        (sync_compare_and_swap_optab, sync_lock_test_and_set_optab,
        sync_old_add_optab, sync_old_sub_optab, sync_old_ior_optab,
        sync_old_and_optab, sync_old_xor_optab, sync_old_nand_optab,
        sync_new_add_optab, sync_new_sub_optab, sync_new_ior_optab,
        sync_new_and_optab, sync_new_xor_optab, sync_new_nand_optab): Read
        from the optab_table, not the direct_optab_table.
        (init_sync_libfuncs): Declare.
        (can_compare_and_swap_p): Update parameters.
        * optabs.c (init_sync_libfuncs_1, init_sync_libfuncs): New.
        (can_compare_and_swap_p): Add allow_libcall parameter; if true,
        test for the legacy compare-and-swap libcall.
        (expand_atomic_exchange): Use the legacy test-and-set libcall.
        (expand_atomic_compare_and_swap): Use the legacy CAS libcall.
        (struct atomic_op_functions): Update for optab type changes.
        (maybe_emit_op): Likewise.
        (expand_atomic_fetch_op): Use the legacy fetch-op libcalls.
        * builtins.c (fold_builtin_atomic_always_lock_free): Update call
        to can_compare_and_swap_p.
        * omp-low.c (expand_omp_atomic_fetch_op): Likewise.
        (expand_omp_atomic_pipeline): Likewise.
        * genopinit.c (optabs): Make sync_old_*_optab, sync_new_*_optab,
        sync_compare_and_swap_optab, sync_lock_test_and_set_optab regular
        optabs.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181134 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 16 insertions, 15 deletions

diff --git a/gcc/java/ChangeLog b/gcc/java/ChangeLog
index 715d1f5885c..27a44f11f7d 100644
--- a/gcc/java/ChangeLog
+++ b/gcc/java/ChangeLog
@@ -1,3 +1,10 @@
+2011-11-07  Richard Henderson  <rth@redhat.com>
+
+	* builtins.c (compareAndSwapInt_builtin): Use can_compare_and_swap_p.
+	(compareAndSwapLong_builtin): Likewise.
+	(compareAndSwapObject_builtin): Likewise.
+	(VMSupportsCS8_builtin): Likewise.
+
 2011-11-02  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* Make-lang.in (jvspec.o): Pass SHLIB instead of SHLIB_LINK.
diff --git a/gcc/java/builtins.c b/gcc/java/builtins.c
index 5ab345dc472..66addcbcc08 100644
--- a/gcc/java/builtins.c
+++ b/gcc/java/builtins.c
@@ -319,9 +319,7 @@ compareAndSwapInt_builtin (tree method_return_type ATTRIBUTE_UNUSED,
 			   tree orig_call)
 {
   enum machine_mode mode = TYPE_MODE (int_type_node);
-  if (direct_optab_handler (sync_compare_and_swap_optab, mode)
-      != CODE_FOR_nothing
-      || flag_use_atomic_builtins)
+  if (can_compare_and_swap_p (mode, flag_use_atomic_builtins))
     {
       tree addr, stmt;
       enum built_in_function fncode = BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_4;
@@ -342,13 +340,12 @@ compareAndSwapLong_builtin (tree method_return_type ATTRIBUTE_UNUSED,
 			    tree orig_call)
 {
   enum machine_mode mode = TYPE_MODE (long_type_node);
-  if (direct_optab_handler (sync_compare_and_swap_optab, 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.  */
+  /* 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.  */
+  if (can_compare_and_swap_p (mode,
+			      (flag_use_atomic_builtins
+			       && GET_MODE_SIZE (mode) <= UNITS_PER_WORD)))
     {
       tree addr, stmt;
       enum built_in_function fncode = BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_8;
@@ -368,9 +365,7 @@ compareAndSwapObject_builtin (tree method_return_type ATTRIBUTE_UNUSED,
 			      tree orig_call)
 {
   enum machine_mode mode = TYPE_MODE (ptr_type_node);
-  if (direct_optab_handler (sync_compare_and_swap_optab, mode)
-      != CODE_FOR_nothing
-      || flag_use_atomic_builtins)
+  if (can_compare_and_swap_p (mode, flag_use_atomic_builtins))
   {
     tree addr, stmt;
     enum built_in_function builtin;
@@ -448,8 +443,7 @@ VMSupportsCS8_builtin (tree method_return_type,
 {
   enum machine_mode mode = TYPE_MODE (long_type_node);
   gcc_assert (method_return_type == boolean_type_node);
-  if (direct_optab_handler (sync_compare_and_swap_optab, mode)
-      != CODE_FOR_nothing)
+  if (can_compare_and_swap_p (mode, false))
     return boolean_true_node;
   else
     return boolean_false_node;