+/* Synchronization primitives. This first set is atomic operation for
+ which we don't care about the resulting value. */
+extern enum insn_code sync_add_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_sub_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_ior_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_and_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_xor_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_nand_optab[NUM_MACHINE_MODES];
+
+/* This second set is atomic operations in which we return the value
+ that existed in memory before the operation. */
+extern enum insn_code sync_old_add_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_old_sub_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_old_ior_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_old_and_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_old_xor_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_old_nand_optab[NUM_MACHINE_MODES];
+
+/* This third set is atomic operations in which we return the value
+ that resulted after performing the operation. */
+extern enum insn_code sync_new_add_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_new_sub_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_new_ior_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_new_and_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_new_xor_optab[NUM_MACHINE_MODES];
+extern enum insn_code sync_new_nand_optab[NUM_MACHINE_MODES];
+
+/* Atomic compare and swap. */
+extern enum insn_code sync_compare_and_swap[NUM_MACHINE_MODES];
+extern enum insn_code sync_compare_and_swap_cc[NUM_MACHINE_MODES];
+
+/* Atomic exchange with acquire semantics. */
+extern enum insn_code sync_lock_test_and_set[NUM_MACHINE_MODES];
+
+/* Atomic clear with release semantics. */
+extern enum insn_code sync_lock_release[NUM_MACHINE_MODES];
+