You are right that the InstanceofStub does not directly touch the floating
point
registers, however it can do a tail call to the builtin INSTANCE_OF and from
there we have no idea of what is actually happening.
In the IA32 version I did MarkAsSaveDoubles in
LChunkBuilder::DoInstanceOfKnownGlobal for the instruction. That will break
the
live range of all double registers, which does also achieve what we want.
Which
approach is the best is difficult to know for sure, but most likely
instanceof
will not be used in the middle of floating point calculations.
So we should go for using MarkAsSaveDoubles instead of a sefepoint with
doubles.
http://codereview.chromium.org/6248004/
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
