I'm curious, does this conversion mean that you lose precision? I'm not sure I care, but it would be good to be sure that people know that we don't do x87 correctly if so.
Did anyone ever consider using softfloat? http://www.jhauser.us/arithmetic/SoftFloat.html Nate On Tue, Sep 3, 2013 at 10:32 AM, Andreas Sandberg <[email protected]> wrote: > On 08/29/2013 11:49 PM, Steve Reinhardt wrote: >> >> What is the status of using kvm for x86 simulation? I know Andreas S. has >> committed a bunch of patches, but I see that x86 is still not listed >> in the is_isa_kvm_compatible() >> function in the SConstruct. Does that mean there are still known issues? > > > Currently, the main issue that has kept me from submitting the patches is > the x87 interface. gem5 uses 64-bit doubles internally to represent floating > point numbers, while the hardware uses 80-bits. The problem boils down to > converting between the two. My current version is using a gcc-specific > 80-bit float type, which is something I need to fix before submitting. I > have the code[1] to do the conversion in software, but I haven't had time to > integrate it into gem5 yet. > > Apart from the FP issues, things should work fine. I've seen less than 10% > slowdown compared to native when executing SPEC and features like CPU > switching and checkpointing work. > > Unfortunately, I don't expect to get time to prepare the code for review > until mid/late September. > > //Andreas > > [1] https://github.com/andysan/libfputils > > > _______________________________________________ > gem5-dev mailing list > [email protected] > http://m5sim.org/mailman/listinfo/gem5-dev _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
