[patch] Shark reroute LLVM atomic intrinsics to Zero

[Andrew Haley]

Robert Schuster wrote:

> Xerxes Rånby schrieb:
>> Greetings,
>> This patch will make shark reroute LLVM atomic intrinsics to the
>> existing atomic operations implemented in Zero.
>>
>> This patch are both platform and arch independent.
>> I have tested this patch on Shark compiled for X86, PPC and ARM.
> I would make this rerouting optional depending on the architecture.
> LLVM has atomic intrinsic fucntion support for x86(-64), powerpc (32,64)
> and alpha. On those architectures you really want to use what LLVM
> provides.
> 
> E.g. on x86 the function is converted into a series of machine
> instructions and no function call.

Definitely; we really don't want a function call just do do an atomic
cmpxchg.  This is really just a workaround for an llvm bug, and hopefully
it'll soon go away.

Andrew.