On Wed, Jan 10, 2007 at 02:10:58PM -0800, Janis Johnson wrote: > On Wed, Jan 10, 2007 at 11:40:46AM -0800, H. J. Lu wrote: > > Both AMD and Intel like to have BID as a configure time option > > for DFP. Intel is planning to contribute a complete BID runtime > > library, which can be used by executables generate by gcc. > > > > As the first step, we'd like to contribute a BID<->DPD library so that > > BID can be used with libdecnumber by executables generate by gcc > > before the complete BID runtime library is ready. > > > > Any comments? > > libdecnumber doesn't use DPD (densely packed decimal), it uses the > decNumber format. Functions in libgcc convert from DPD to decNumber, > call into libdecnumber to do computations, and then convert the result > back to DPD. It's all parameterized in dfp-bit.[ch], so replacing > conversions between decNumber structs and DPD with conversions between > decNumber structs and BID (binary integer decimal) should be > straightforward; I don't think there's any need to convert between BID > and DPD to use libdecnumber.
libdecnumber is used by both gcc and DFP executables. We only want to use BID for DFP executables. That means we will need BID<->decNumber for gcc to generate DFP executables which use the BID library. Since the real BID library won't be ready for a while and in the meantime, we like to enable BID for gcc now, that is why we propose the BID<->DPD<->libdecnumber approach as a stopgap measure. We can plug in the real BID library later. > > If all x86* targets will use BID then there's no need for a configure > option. Initial support using DPD for x86* was a proof of concept, I > doubt that anyone would care if you replace it with BID support. Glad to hear that. We can make it BID only for x86. H.J.
