}
#endif
+/* Expand a membar instruction for various use cases. Both the LOAD_STORE
+ and BEFORE_AFTER arguments of the form X_Y. They are two-bit masks where
+ bit 0 indicates that X is true, and bit 1 indicates Y is true. */
+
+void
+sparc_emit_membar_for_model (enum memmodel model,
+ int load_store, int before_after)
+{
+ /* Bits for the MEMBAR mmask field. */
+ const int LoadLoad = 1;
+ const int StoreLoad = 2;
+ const int LoadStore = 4;
+ const int StoreStore = 8;
+
+ int mm = 0;
+
+ if (before_after & 1)
+ {
+ if (model == MEMMODEL_ACQUIRE
+ || model == MEMMODEL_ACQ_REL
+ || model == MEMMODEL_SEQ_CST)
+ {
+ if (load_store & 1)
+ mm |= LoadLoad | LoadStore;
+ if (load_store & 2)
+ mm |= StoreLoad | StoreStore;
+ }
+ }
+ if (before_after & 2)
+ {
+ if (model == MEMMODEL_RELEASE
+ || model == MEMMODEL_ACQ_REL
+ || model == MEMMODEL_SEQ_CST)
+ {
+ if (load_store & 1)
+ mm |= LoadLoad | StoreLoad;
+ if (load_store & 2)
+ mm |= LoadStore | StoreStore;
+ }
+ }
+
+ /* For raw barriers (before+after), always emit a barrier.
+ This will become a compile-time barrier if needed. */
+ if (mm || before_after == 3)
+ emit_insn (gen_membar (GEN_INT (mm)));
+}
+
/* Expand code to perform a 8 or 16-bit compare and swap by doing 32-bit
compare and swap on the word containing the byte or half-word. */
;; GCC machine description for SPARC synchronization instructions.
-;; Copyright (C) 2005, 2007, 2009, 2010
+;; Copyright (C) 2005, 2007, 2009, 2010, 2011
;; Free Software Foundation, Inc.
;;
;; This file is part of GCC.
(define_mode_iterator I48MODE [SI (DI "TARGET_ARCH64 || TARGET_V8PLUS")])
(define_mode_attr modesuffix [(SI "") (DI "x")])
+(define_expand "mem_thread_fence"
+ [(match_operand:SI 0 "const_int_operand")]
+ "TARGET_V8 || TARGET_V9"
+{
+ enum memmodel model = (enum memmodel) INTVAL (operands[0]);
+ sparc_emit_membar_for_model (model, 3, 3);
+ DONE;
+})
+
(define_expand "memory_barrier"
- [(set (match_dup 0)
- (unspec:BLK [(match_dup 0)] UNSPEC_MEMBAR))]
+ [(const_int 0)]
+ "TARGET_V8 || TARGET_V9"
+{
+ sparc_emit_membar_for_model (MEMMODEL_SEQ_CST, 3, 3);
+ DONE;
+})
+
+(define_expand "membar"
+ [(set (match_dup 1)
+ (unspec:BLK [(match_dup 1)
+ (match_operand:SI 0 "const_int_operand")]
+ UNSPEC_MEMBAR))]
"TARGET_V8 || TARGET_V9"
{
- operands[0] = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (Pmode));
- MEM_VOLATILE_P (operands[0]) = 1;
+ operands[1] = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (Pmode));
+ MEM_VOLATILE_P (operands[1]) = 1;
})
-;; In V8, loads are blocking and ordered wrt earlier loads, i.e. every load
-;; is virtually followed by a load barrier (membar #LoadStore | #LoadLoad).
-;; In PSO, stbar orders the stores (membar #StoreStore).
-;; In TSO, ldstub orders the stores wrt subsequent loads (membar #StoreLoad).
-;; The combination of the three yields a full memory barrier in all cases.
+;; A compiler-only memory barrier. Generic code, when checking for the
+;; existance of various named patterns, uses asm("":::"memory") when we
+;; don't need an actual instruction. Here, it's easiest to pretend that
+;; membar 0 is such a barrier. Further, this gives us a nice hook to
+;; ignore all such barriers on Sparc V7.
+(define_insn "*membar_empty"
+ [(set (match_operand:BLK 0 "" "")
+ (unspec:BLK [(match_dup 0) (match_operand:SI 1 "zero_or_v7_operand")]
+ UNSPEC_MEMBAR))]
+ ""
+ ""
+ [(set_attr "type" "multi")
+ (set_attr "length" "0")])
+
+;; For V8, STBAR is exactly membar #StoreStore, by definition.
+(define_insn "*membar_storestore"
+ [(set (match_operand:BLK 0 "" "")
+ (unspec:BLK [(match_dup 0) (const_int 8)] UNSPEC_MEMBAR))]
+ "TARGET_V8"
+ "stbar"
+ [(set_attr "type" "multi")])
+
+;; For V8, LDSTUB has the effect of membar #StoreLoad
+(define_insn "*membar_storeload"
+ [(set (match_operand:BLK 0 "" "")
+ (unspec:BLK [(match_dup 0) (const_int 2)] UNSPEC_MEMBAR))]
+ "TARGET_V8"
+ "ldstub\t[%%sp-1], %%g0"
+ [(set_attr "type" "multi")])
+
+;; Put the two together, in combination with the fact that V8 implements PSO
+;; as its weakest memory model, means a full barrier. Match all remaining
+;; instances of the membar pattern for Sparc V8.
(define_insn "*membar_v8"
[(set (match_operand:BLK 0 "" "")
- (unspec:BLK [(match_dup 0)] UNSPEC_MEMBAR))]
+ (unspec:BLK [(match_dup 0) (match_operand:SI 1 "const_int_operand")]
+ UNSPEC_MEMBAR))]
"TARGET_V8"
"stbar\n\tldstub\t[%%sp-1], %%g0"
[(set_attr "type" "multi")
(set_attr "length" "2")])
-;; membar #StoreStore | #LoadStore | #StoreLoad | #LoadLoad
+;; For V9, we have the full membar instruction.
(define_insn "*membar"
[(set (match_operand:BLK 0 "" "")
- (unspec:BLK [(match_dup 0)] UNSPEC_MEMBAR))]
+ (unspec:BLK [(match_dup 0) (match_operand:SI 1 "const_int_operand")]
+ UNSPEC_MEMBAR))]
"TARGET_V9"
- "membar\t15"
+ "membar\t%1"
[(set_attr "type" "multi")])
+;;;;;;;;
+
(define_expand "sync_compare_and_swap<mode>"
[(match_operand:I12MODE 0 "register_operand" "")
(match_operand:I12MODE 1 "memory_operand" "")
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