On Sun, 16 Oct 2016, Borislav Petkov wrote: > > The spec can be found in Intel Software Developer Manual or in > > Instruction Set Extensions Programming Reference. See > > https://software.intel.com/sites/default/files/managed/69/78/319433-025.pdf. > > > +/* Intel-defined CPU features, CPUID level 0x00000007:0 (edx), word 18 */ > > +#define X86_FEATURE_AVX512_4VNNIW (18*32+2) /* AVX-512 Neural Network > > Instructions */ > > +#define X86_FEATURE_AVX512_4FMAPS (18*32+3) /* AVX-512 Multiply > > Accumulation Single precision */ > > This is getting ridiculous: we keep adding new leafs to > ->x86_capability, thus bloating cpuinfo_x86 but then it is not even > worth it - this patch defines only two bits.
What's worse is that the Instruction Set Extensions Programming Reference manual says: CPUID.(EAX=07H, ECX=0):EDX[bit 02] AVX512_4FMAPS CPUID.(EAX=07H, ECX=0):EBX[bit 03] AVX512_4VNNIW So AVX512_4VNNIW is in EBX not EDX. What's correct here? The manual or the patch? I'm going to zap it. Thanks, tglx