On 06/17/2011 02:12 PM, Andrew MacLeod wrote:
--- machmode.h (working copy)
*************** extern enum machine_mode ptr_mode;
*** 275,278 ****
--- 275,291 ----
/* Target-dependent machine mode initialization - in insn-modes.c. */
extern void init_adjust_machine_modes (void);
+ /* Memory model types for the __sync_mem* builtins.
+ This must match the order in libstdc++-v3/include/bits/atomic_base.h. */
+ enum memmodel
+ {
+ MEMMODEL_RELAXED = 0,
+ MEMMODEL_CONSUME = 1,
+ MEMMODEL_ACQUIRE = 2,
+ MEMMODEL_RELEASE = 3,
+ MEMMODEL_ACQ_REL = 4,
+ MEMMODEL_SEQ_CST = 5,
+ MEMMODEL_LAST = 6
+ };
This isn't a very machine mode sort of define.
I think coretypes.h is a better choice.
cool that seems to work fine. As long as its somewhere common.
+ static rtx
+ expand_builtin_mem_exchange (enum machine_mode mode, tree exp, rtx target)
Some names include "sync" and some don't?
Well, I was going to blame Aldy :-) but then I went to look at this,
and thats the same way *all* the other __sync instructions seem to be.
ie:
builtins.c:expand_builtin_lock_test_and_set (enum machine_mode mode,
tree exp,
builtins.c: case BUILT_IN_LOCK_TEST_AND_SET_1:
builtins.c: case BUILT_IN_LOCK_TEST_AND_SET_2:
builtins.c: case BUILT_IN_LOCK_TEST_AND_SET_4:
whereas everything else is 'sync_lock_test_and_set'..
So i guess it falls to prior art... I assume Aldy just cut-and-pasted
for his new routine and just changed the names in the same format.
+
The xchg instruction is a full barrier; no need for anything extra here.
Indeed, you needn't define UNSPECV_MEM_XCHG either. This could be as
simple as
Ah, even better. For some reason I thought I saw somewhere that it
wasn't a full barrier. Might have just been the documentation for
lock_test_and_set.
Andrew
