cris.c (cris_init_libfuncs): Handle initialization of library functions for…

cris.c (cris_init_libfuncs): Handle initialization of library functions for basic atomic compare-and-swap.

	* config/cris/cris.c (cris_init_libfuncs): Handle initialization
	of library functions for basic atomic compare-and-swap.
	* config/cris/cris.h (TARGET_ATOMICS_MAY_CALL_LIBFUNCS): New macro.
	* config/cris/cris.opt (munaligned-atomic-may-use-library): New
	option.
	* config/cris/sync.md ("atomic_fetch_<atomic_op_name><mode>")
	("cris_atomic_fetch_<atomic_op_name><mode>_1")
	("atomic_compare_and_swap<mode>")
	("cris_atomic_compare_and_swap<mode>_1"): Make
	conditional on TARGET_ATOMICS_MAY_CALL_LIBFUNCS for
	sizes larger than byte.

From-SVN: r189504

gcc/ChangeLog

 2012-07-16  Hans-Peter Nilsson  <hp@axis.com>
 
+	* config/cris/cris.c (cris_init_libfuncs): Handle initialization
+	of library functions for basic atomic compare-and-swap.
+	* config/cris/cris.h (TARGET_ATOMICS_MAY_CALL_LIBFUNCS): New macro.
+	* config/cris/cris.opt (munaligned-atomic-may-use-library): New
+	option.
+	* config/cris/sync.md ("atomic_fetch_<atomic_op_name><mode>")
+	("cris_atomic_fetch_<atomic_op_name><mode>_1")
+	("atomic_compare_and_swap<mode>")
+	("cris_atomic_compare_and_swap<mode>_1"): Make
+	conditional on TARGET_ATOMICS_MAY_CALL_LIBFUNCS for
+	sizes larger than byte.
 	* config/cris/cris.c (cris_print_operand) <case 'P', 'q'>: New cases.
 	* config/cris/sync.md (atomic_op_op_cnstr): New code_attr.
 	(atomic_op_op_pred): Ditto.

gcc/config/cris/cris.c

@@ -2761,6 +2761,16 @@ cris_init_libfuncs (void)
   set_optab_libfunc (udiv_optab, SImode, "__Udiv");
   set_optab_libfunc (smod_optab, SImode, "__Mod");
   set_optab_libfunc (umod_optab, SImode, "__Umod");
+
+  /* Atomic data being unaligned is unfortunately a reality.
+     Deal with it.  */
+  if (TARGET_ATOMICS_MAY_CALL_LIBFUNCS)
+    {
+      set_optab_libfunc (sync_compare_and_swap_optab, SImode,
+			 "__cris_atcmpxchgr32");
+      set_optab_libfunc (sync_compare_and_swap_optab, HImode,
+			 "__cris_atcmpxchgr16");
+    }
 }
 
 /* The INIT_EXPANDERS worker sets the per-function-data initializer and

gcc/config/cris/cris.h

@@ -316,6 +316,11 @@ extern int cris_cpu_version;
 #define TARGET_TRAP_USING_BREAK8 \
  (cris_trap_using_break8 == 2 ? TARGET_HAS_BREAK : cris_trap_using_break8)
 
+/* Call library functions by default for GNU/Linux.  */
+#define TARGET_ATOMICS_MAY_CALL_LIBFUNCS		\
+ (cris_atomics_calling_libfunc == 2			\
+  ? TARGET_LINUX : cris_atomics_calling_libfunc)
+
 /* The < v10 atomics turn off interrupts, so they don't need alignment.
    Incidentally, by default alignment is off there causing variables to
    be default unaligned all over, so we'd have to make support

gcc/config/cris/cris.opt

@@ -183,6 +183,10 @@ mtrap-unaligned-atomic
 Target Report Var(cris_trap_unaligned_atomic) Init(2)
 Emit checks causing \"break 8\" instructions to execute when applying atomic builtins on misaligned memory
 
+munaligned-atomic-may-use-library
+Target Report Var(cris_atomics_calling_libfunc) Init(2)
+Handle atomic builtins that may be applied to unaligned data by calling library functions. Overrides -mtrap-unaligned-atomic.
+
 ; TARGET_SVINTO: Currently this just affects alignment.  FIXME:
 ; Redundant with TARGET_ALIGN_BY_32, or put machine stuff here?
 ; This and the others below could just as well be variables and

gcc/config/cris/sync.md

@@ -130,7 +130,7 @@
    (set (match_operand:BWD 0 "register_operand" "=&r")
 	(match_dup 1))
    (clobber (match_scratch:SI 3 "=&r"))]
-  ""
+  "<MODE>mode == QImode || !TARGET_ATOMICS_MAY_CALL_LIBFUNCS"
 {
   /* Can't be too sure; better ICE if this happens.  */
   gcc_assert (!reg_overlap_mentioned_p (operands[2], operands[1]));
@@ -210,7 +210,7 @@
    (match_operand 5)
    (match_operand 6)
    (match_operand 7)]
-  ""
+  "<MODE>mode == QImode || !TARGET_ATOMICS_MAY_CALL_LIBFUNCS"
 {
   enum memmodel mmodel = (enum memmodel) INTVAL (operands[6]);
 
@@ -244,7 +244,7 @@
 	  (match_dup 3)
 	  (match_operand:BWD 4 "register_operand" "r")]
 	 CRIS_UNSPEC_ATOMIC_SWAP_MEM))]
-  ""
+  "<MODE>mode == QImode || !TARGET_ATOMICS_MAY_CALL_LIBFUNCS"
 {
   if (TARGET_V32)
     return