Here's the patch for __sync_mem_load, complete with tests.
I'll change and correct the actual implementation of the load pattern
later ( I think I have the x86 fence wrong). It occurs to me that if I
implement the __sync_mem_thread_fence (model) routine, then the
appropriate fences can be created by using that __sync instead of
sync_synchronize all the time as well.
Im trying to gather a set of optimal, or at least decent, sequences for
each pattern. I'll go back and make changes when I have collected some
and finished all the other atomic operations. It'll be easier then.
Andrew
* doc/extend.texi (__sync_mem_load): Document.
* c-family/c-common.c (resolve_overloaded_builtin): Add
BUILT_IN_SYNC_MEM_LOAD_N.
* optabs.c (expand_sync_mem_load): New.
* optabs.h (enum direct_optab_index): Add DOI_sync_mem_load.
(sync_mem_load_optab): Define.
* genopinit.c: Add entry for sync_mem_load.
* builtins.c (expand_builtin_sync_mem_load): New.
(expand_builtin): Handle BUILT_IN_SYNC_MEM_LOAD_*
* sync-bultins.def: Add entries for BUILT_IN_SYNC_MEM_LOAD_*.
* testsuite/gcc.dg/sync-mem-invalid.c: Add invalid load tests.
* testsuite/gcc.dg/sync-mem.h: Add load executable tests.
* builtin-types.def (BT_FN_I{1,2,4,8,16}_VPTR_INT): New.
* expr.h (expand_sync_mem_load): Declare.
* fortran/types.def (BT_FN_I{1,2,4,8,16}_VPTR_INT): New.
* config/i386/sync.md (sync_mem_load<mode>): New pattern.
Index: doc/extend.texi
===================================================================
*** doc/extend.texi (revision 175331)
--- doc/extend.texi (working copy)
*************** This means that all previous memory stor
*** 6729,6734 ****
--- 6729,6747 ----
previous memory loads have been satisfied, but following memory reads
are not prevented from being speculated to before the barrier.
+ @item @var{type} __sync_mem_load (@var{type} *ptr, int memmodel, ...)
+ @findex __sync_mem_load
+ This builtin implements an atomic load operation within the constraints of a
+ memory model. It returns the contents of @code{*@var{ptr}}.
+
+ The valid memory model variants for this builtin are
+ __SYNC_MEM_RELAXED, __SYNC_MEM_SEQ_CST, __SYNC_MEM_ACQUIRE, and
+ __SYNC_MEM_CONSUME. The target pattern is responsible
+ for issuing the different synchronization instructions. It should default to
+ the more restrictive memory model, the sequentially consistent model. If
+ nothing is implemented for the target, the compiler will implement it by
+ issuing a memory barrier, the load, and then another memory barrier.
+
@item @var{type} __sync_mem_exchange (@var{type} *ptr, @var{type} value, int
memmodel, ...)
@findex __sync_mem_exchange
This builtin implements an atomic exchange operation within the
Index: c-family/c-common.c
===================================================================
*** c-family/c-common.c (revision 175331)
--- c-family/c-common.c (working copy)
*************** resolve_overloaded_builtin (location_t l
*** 9061,9066 ****
--- 9061,9067 ----
case BUILT_IN_SYNC_LOCK_TEST_AND_SET_N:
case BUILT_IN_SYNC_LOCK_RELEASE_N:
case BUILT_IN_SYNC_MEM_EXCHANGE_N:
+ case BUILT_IN_SYNC_MEM_LOAD_N:
{
int n = sync_resolve_size (function, params);
tree new_function, first_param, result;
Index: optabs.c
===================================================================
*** optabs.c (revision 175331)
--- optabs.c (working copy)
*************** expand_sync_lock_test_and_set (rtx mem,
*** 7057,7062 ****
--- 7057,7104 ----
return NULL_RTX;
}
+ /* This function expands the atomic load operation:
+ return the atomically loaded value in MEM.
+
+ MEMMODEL is the memory model variant to use.
+ TARGET is an option place to stick the return value. */
+
+ rtx
+ expand_sync_mem_load (enum memmodel model, rtx mem, rtx target)
+ {
+ enum machine_mode mode = GET_MODE (mem);
+ enum insn_code icode;
+
+ /* If the target supports the load directly, great. */
+ icode = direct_optab_handler (sync_mem_load_optab, mode);
+ if (icode != CODE_FOR_nothing)
+ {
+ struct expand_operand ops[3];
+
+ create_output_operand (&ops[0], target, mode);
+ create_fixed_operand (&ops[1], mem);
+ create_integer_operand (&ops[2], model);
+ if (maybe_expand_insn (icode, 3, ops))
+ return ops[0].value;
+ }
+
+ /* For any model other than RELAXED, perform a synchronization first. */
+ if (model != MEMMODEL_RELAXED)
+ expand_builtin_sync_synchronize ();
+
+ /* If the result is unused, don't bother loading. */
+ if (target != const0_rtx)
+ emit_move_insn (target, mem);
+ else
+ target = NULL_RTX;
+
+ /* For SEQ_CST, also emit a barrier after the load. */
+ if (model == MEMMODEL_SEQ_CST)
+ expand_builtin_sync_synchronize ();
+
+ return target;
+ }
+
/* This function expands the atomic exchange operation:
atomically store VAL in MEM and return the previous value in MEM.
Index: optabs.h
===================================================================
*** optabs.h (revision 175331)
--- optabs.h (working copy)
*************** enum direct_optab_index
*** 679,684 ****
--- 679,685 ----
/* Atomic operations with C++0x memory model parameters. */
DOI_sync_mem_exchange,
+ DOI_sync_mem_load,
DOI_MAX
};
*************** typedef struct direct_optab_d *direct_op
*** 730,735 ****
--- 731,738 ----
#define sync_mem_exchange_optab \
(&direct_optab_table[(int) DOI_sync_mem_exchange])
+ #define sync_mem_load_optab \
+ (&direct_optab_table[(int) DOI_sync_mem_load])
/* Target-dependent globals. */
struct target_optabs {
Index: genopinit.c
===================================================================
*** genopinit.c (revision 175331)
--- genopinit.c (working copy)
*************** static const char * const optabs[] =
*** 242,247 ****
--- 242,248 ----
"set_direct_optab_handler (sync_lock_test_and_set_optab, $A,
CODE_FOR_$(sync_lock_test_and_set$I$a$))",
"set_direct_optab_handler (sync_lock_release_optab, $A,
CODE_FOR_$(sync_lock_release$I$a$))",
"set_direct_optab_handler (sync_mem_exchange_optab, $A,
CODE_FOR_$(sync_mem_exchange$I$a$))",
+ "set_direct_optab_handler (sync_mem_load_optab, $A,
CODE_FOR_$(sync_mem_load$I$a$))",
"set_optab_handler (vec_set_optab, $A, CODE_FOR_$(vec_set$a$))",
"set_optab_handler (vec_extract_optab, $A, CODE_FOR_$(vec_extract$a$))",
"set_optab_handler (vec_extract_even_optab, $A,
CODE_FOR_$(vec_extract_even$a$))",
Index: builtins.c
===================================================================
*** builtins.c (revision 175331)
--- builtins.c (working copy)
*************** get_memmodel (tree exp)
*** 5221,5226 ****
--- 5221,5255 ----
return (enum memmodel) INTVAL (op);
}
+ /* Expand the __sync_mem_load intrinsic:
+
+ TYPE __sync_mem_load (TYPE *to, TYPE from, enum memmodel)
+
+ EXP is the CALL_EXPR.
+ TARGET is an optional place for us to store the results. */
+
+ static rtx
+ expand_builtin_sync_mem_load (enum machine_mode mode, tree exp, rtx target)
+ {
+ rtx mem;
+ enum memmodel model;
+
+ model = get_memmodel (CALL_EXPR_ARG (exp, 1));
+ if (model != MEMMODEL_RELAXED
+ && model != MEMMODEL_SEQ_CST
+ && model != MEMMODEL_CONSUME
+ && model != MEMMODEL_ACQUIRE)
+ {
+ error ("invalid memory model for %<__sync_mem_load%>");
+ return NULL_RTX;
+ }
+
+ /* Expand the operand. */
+ mem = get_builtin_sync_mem (CALL_EXPR_ARG (exp, 0), mode);
+
+ return expand_sync_mem_load (model, mem, target);
+ }
+
/* Expand the __sync_mem_exchange intrinsic:
TYPE __sync_mem_exchange (TYPE *to, TYPE from, enum memmodel)
*************** expand_builtin (tree exp, rtx target, rt
*** 6077,6082 ****
--- 6106,6123 ----
return target;
break;
+ case BUILT_IN_SYNC_MEM_LOAD_1:
+ case BUILT_IN_SYNC_MEM_LOAD_2:
+ case BUILT_IN_SYNC_MEM_LOAD_4:
+ case BUILT_IN_SYNC_MEM_LOAD_8:
+ case BUILT_IN_SYNC_MEM_LOAD_16:
+ mode = get_builtin_sync_mode (fcode - BUILT_IN_SYNC_MEM_LOAD_1);
+ target = expand_builtin_sync_mem_load (mode, exp, target);
+ if (target)
+ return target;
+ break;
+
+
case BUILT_IN_SYNC_MEM_EXCHANGE_1:
case BUILT_IN_SYNC_MEM_EXCHANGE_2:
case BUILT_IN_SYNC_MEM_EXCHANGE_4:
Index: sync-builtins.def
===================================================================
*** sync-builtins.def (revision 175331)
--- sync-builtins.def (working copy)
*************** DEF_SYNC_BUILTIN (BUILT_IN_SYNC_SYNCHRON
*** 259,264 ****
--- 259,283 ----
/* __sync* builtins for the C++ memory model. */
+ DEF_SYNC_BUILTIN (BUILT_IN_SYNC_MEM_LOAD_N,
+ "__sync_mem_load",
+ BT_FN_VOID_VAR, ATTR_NOTHROW_LEAF_LIST)
+ DEF_SYNC_BUILTIN (BUILT_IN_SYNC_MEM_LOAD_1,
+ "__sync_mem_load_1",
+ BT_FN_I1_VPTR_INT, ATTR_NOTHROW_LEAF_LIST)
+ DEF_SYNC_BUILTIN (BUILT_IN_SYNC_MEM_LOAD_2,
+ "__sync_mem_load_2",
+ BT_FN_I2_VPTR_INT, ATTR_NOTHROW_LEAF_LIST)
+ DEF_SYNC_BUILTIN (BUILT_IN_SYNC_MEM_LOAD_4,
+ "__sync_mem_load_4",
+ BT_FN_I4_VPTR_INT, ATTR_NOTHROW_LEAF_LIST)
+ DEF_SYNC_BUILTIN (BUILT_IN_SYNC_MEM_LOAD_8,
+ "__sync_mem_load_8",
+ BT_FN_I8_VPTR_INT, ATTR_NOTHROW_LEAF_LIST)
+ DEF_SYNC_BUILTIN (BUILT_IN_SYNC_MEM_LOAD_16,
+ "__sync_mem_load_16",
+ BT_FN_I16_VPTR_INT, ATTR_NOTHROW_LEAF_LIST)
+
DEF_SYNC_BUILTIN (BUILT_IN_SYNC_MEM_EXCHANGE_N,
"__sync_mem_exchange",
BT_FN_VOID_VAR, ATTR_NOTHROW_LEAF_LIST)
Index: testsuite/gcc.dg/sync-mem-invalid.c
===================================================================
*** testsuite/gcc.dg/sync-mem-invalid.c (revision 175331)
--- testsuite/gcc.dg/sync-mem-invalid.c (working copy)
*************** int i;
*** 8,11 ****
--- 8,13 ----
main ()
{
__sync_mem_exchange (&i, 1, __SYNC_MEM_CONSUME); /* { dg-error "invalid
memory model" } */
+ __sync_mem_load (&i, __SYNC_MEM_RELEASE); /* { dg-error "invalid memory
model" } */
+ __sync_mem_load (&i, __SYNC_MEM_ACQ_REL); /* { dg-error "invalid memory
model" } */
}
Index: testsuite/gcc.dg/sync-mem.h
===================================================================
*** testsuite/gcc.dg/sync-mem.h (revision 175331)
--- testsuite/gcc.dg/sync-mem.h (working copy)
*************** void test_exchange()
*** 18,27 ****
EXCHANGE (v, __SYNC_MEM_SEQ_CST);
}
main ()
{
! test_exchange();
return 0;
}
--- 18,39 ----
EXCHANGE (v, __SYNC_MEM_SEQ_CST);
}
+ #define LOAD(VAR, MODE) if (__sync_mem_load (&VAR, MODE) != count++) abort();
else VAR++
+
+ void test_load()
+ {
+ v = 0;
+ count = 0;
+ LOAD (v, __SYNC_MEM_RELAXED);
+ LOAD (v, __SYNC_MEM_ACQUIRE);
+ LOAD (v, __SYNC_MEM_CONSUME);
+ LOAD (v, __SYNC_MEM_SEQ_CST);
+ }
main ()
{
! test_exchange ();
! test_load ();
return 0;
}
Index: builtin-types.def
===================================================================
*** builtin-types.def (revision 175331)
--- builtin-types.def (working copy)
*************** DEF_FUNCTION_TYPE_2 (BT_FN_BOOL_LONGPTR_
*** 315,320 ****
--- 315,325 ----
BT_BOOL, BT_PTR_LONG, BT_PTR_LONG)
DEF_FUNCTION_TYPE_2 (BT_FN_BOOL_ULONGLONGPTR_ULONGLONGPTR,
BT_BOOL, BT_PTR_ULONGLONG, BT_PTR_ULONGLONG)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I1_VPTR_INT, BT_I1, BT_VOLATILE_PTR, BT_INT)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I2_VPTR_INT, BT_I2, BT_VOLATILE_PTR, BT_INT)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I4_VPTR_INT, BT_I4, BT_VOLATILE_PTR, BT_INT)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I8_VPTR_INT, BT_I8, BT_VOLATILE_PTR, BT_INT)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I16_VPTR_INT, BT_I16, BT_VOLATILE_PTR, BT_INT)
DEF_POINTER_TYPE (BT_PTR_FN_VOID_PTR_PTR, BT_FN_VOID_PTR_PTR)
Index: expr.h
===================================================================
*** expr.h (revision 175331)
--- expr.h (working copy)
*************** rtx expand_bool_compare_and_swap (rtx, r
*** 217,222 ****
--- 217,223 ----
rtx expand_sync_operation (rtx, rtx, enum rtx_code);
rtx expand_sync_fetch_operation (rtx, rtx, enum rtx_code, bool, rtx);
rtx expand_sync_lock_test_and_set (rtx, rtx, rtx);
+ rtx expand_sync_mem_load (enum memmodel, rtx, rtx);
rtx expand_sync_mem_exchange (enum memmodel, rtx, rtx, rtx);
/* Functions from expmed.c: */
Index: fortran/types.def
===================================================================
*** fortran/types.def (revision 175331)
--- fortran/types.def (working copy)
*************** DEF_FUNCTION_TYPE_2 (BT_FN_I4_VPTR_I4, B
*** 98,103 ****
--- 98,108 ----
DEF_FUNCTION_TYPE_2 (BT_FN_I8_VPTR_I8, BT_I8, BT_VOLATILE_PTR, BT_I8)
DEF_FUNCTION_TYPE_2 (BT_FN_I16_VPTR_I16, BT_I16, BT_VOLATILE_PTR, BT_I16)
DEF_FUNCTION_TYPE_2 (BT_FN_VOID_PTR_PTR, BT_VOID, BT_PTR, BT_PTR)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I1_VPTR_INT, BT_I1, BT_VOLATILE_PTR, BT_INT)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I2_VPTR_INT, BT_I2, BT_VOLATILE_PTR, BT_INT)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I4_VPTR_INT, BT_I4, BT_VOLATILE_PTR, BT_INT)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I8_VPTR_INT, BT_I8, BT_VOLATILE_PTR, BT_INT)
+ DEF_FUNCTION_TYPE_2 (BT_FN_I16_VPTR_INT, BT_I16, BT_VOLATILE_PTR, BT_INT)
DEF_POINTER_TYPE (BT_PTR_FN_VOID_PTR_PTR, BT_FN_VOID_PTR_PTR)
Index: config/i386/sync.md
===================================================================
*** config/i386/sync.md (revision 175331)
--- config/i386/sync.md (working copy)
***************
*** 232,237 ****
--- 232,252 ----
return "lock{%;} add{<imodesuffix>}\t{%1, %0|%0, %1}";
})
+
+ (define_expand "sync_mem_load<mode>"
+ [(match_operand:SWI 0 "register_operand" "") ;; output
+ (match_operand:SWI 1 "memory_operand" "") ;; memory
+ (match_operand:SI 2 "const_int_operand" "")] ;; memory model
+ ""
+ {
+ if (INTVAL (operands[2]) == MEMMODEL_ACQUIRE ||
+ INTVAL (operands[2]) == MEMMODEL_SEQ_CST)
+ expand_builtin_sync_synchronize ();
+ ix86_expand_move (<MODE>mode, operands);
+ DONE;
+ })
+
+
(define_expand "sync_mem_exchange<mode>"
[(match_operand:SWI 0 "register_operand" "") ;; output
(match_operand:SWI 1 "memory_operand" "") ;; memory
