Java: add flag_use_atomic_builtins

[Paolo Bonzini]

On 08/12/2009 06:52 PM, Andrew Haley wrote:
> Joseph S. Myers wrote:
>> On Wed, 12 Aug 2009, Andrew Haley wrote:
>>
>>> Some targets, particularly ARM, don't have instructions for things
>>> such as sync_compare_and_swap.  Instead, a routine in libgcc is
>>> used.  This patch adds a new gcj option, -fuse-atomic-builtins,
>>> which causes gcj to use the routines in libgcc whenever atomic
>>> operations are needed.
>> Wouldn't a target hook to allow a target to declare which operations it
>> provides in libgcc be better than a command-line option?
>
> Maybe it would.  I'm happy to work with anyone to create such a
> thing.  What would such a hook look like, and how would a front-
> end use it?

Couldn't optabs be (re)used?

Paolo