On 01/30/2017 07:54 PM, Torvald Riegel wrote:
This patch fixes the __atomic builtins to not implement supposedly
lock-free atomic loads based on just a compare-and-swap operation.
Hi,
The internals doc still lists CAS (
https://gcc.gnu.org/onlinedocs/gccint/Standard-Names.html#index-atomic_005floadmode-instruction-pattern
):
...
‘atomic_loadmode’
This pattern implements an atomic load operation with memory model
semantics. Operand 1 is the memory address being loaded from. Operand 0
is the result of the load. Operand 2 is the memory model to be used for
the load operation.
If not present, the __atomic_load built-in function will either
resort to a normal load with memory barriers, or a compare-and-swap
operation if a normal load would not be atomic.
...
Thanks,
- Tom
