Alan Stange <stange@rentec.com> writes:
> I believe the trick here is that Solaris 10 will only run on v9 hardware
> (or the sun4u systems), which all have the instruction. But the v8 ABI
> "model" doesn't have it. So, in some sense the ABI doesn't "allow"
> this instruction, but the hardware does, so they can just slam it in
> knowing that it'll work.
Well, that might be OK for Sun's compiler since they know what a given
version of Solaris will run on. But I don't think we can adopt the same
attitude for our gcc code path; that has to work on Sparc-based Linuxen
and BSDen. I don't think it's appropriate to kiss off support for v8
chips when we haven't seen any proof at all of a performance boost in
return.
Maybe the right answer is to leave the code as-is, ie, deliberately not
the same for Sun and gcc compilers.
regards, tom lane
