Hi Matt, The different instructions between 2F and 3A is: madd instruction: 2F has two operands , 3A has three ones The English version of Loongson3A usermanualis not available now, I will translating part of it and email you ASAP. Regards, xiuzhi > > To Matt, > > At first thank you very much for your pixman work. In my opinion, Loongson-3 > has the same MMI/SIMD instructions as Loongson-2. The only difference is > that Loongson-2's MMI/SIMD trigger COP1 exception, and Loongson-3's MMI/SIMD > trigger COP2 exception, so we need this patch to make pixman work fine. > > To Xiuzhi, > > Do you have an English version of Loongson-3's user mannual? I think that > will be very useful for Matt. > > Huacai > > > On Fri, Apr 4, 2014 at 1:11 AM, Huacai Chen <chenhc@xxxxxxxxxx> wrote: > >> Loongson-3 has some specific instructions (MMI/SIMD) in coprocessor 2. > >> COP2 isn't independent because it share COP1 (FPU)'s registers. This > >> patch enable the COP2 usage so user-space programs can use the MMI/SIMD > >> instructions. When COP2 exception happens, we enable both COP1 (FPU) > >> and COP2, only in this way the fp context can be saved and restored > >> correctly. > > > > Is there a Loongson 3 programmers manual somewhere, similar to > > Loongson2FUserGuide.pdf? > > > > I optimized pixman for Loongson 2E/2F using their SIMD instructions. > > I've compiled pixman for Loongson 3A and I see some new instructions > > being used in the disassembly, but I have no Loongson 3 system to test > > on. At minimum, having a manual would be nice. > > > > Thanks, > > Matt > > > >
