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 >
