On 11.02.2014, at 18:14, Tom Musta <tommu...@gmail.com> wrote: > QEMU is currently lacking support for the Decimal Floating Point category of > instructions > (see Power ISA V2.07 Chapter 6). I intend to add this support. > > Has this topic been investigated before and if so can anyone point me to that > discussion? > A Google search came up empty for me. > > My proposal is to incorporate the libdecnumber component of libdfp > (http://www.eglibc.org/cgi-bin/viewvc.cgi/libdfp/trunk/) in a manner > analogous to how > softfloat is used for binary floating point. So, for example, the helper for > the dadd > instruction would look something like the following: > > - map FPSCR state to a decContext. > - convert the contents of the source FPRs to decNumbers (decimal64ToNumber). > - call decNumberAdd > - convert the resultant decNumber to DPD (decimal64FromNumber) > - update FPSCR per the decContext.status and result. > > Comments?
I think that approach makes a lot of sense, but let's ask Richard and Peter as well. Alex
