Erro in libgmp when making fdk-aac

[Michael Fuckner]

Hi,

I just checked microcode Version: 0x8a is used for CPUID 0x506e3- 
Intel's Linux Processor Microcode Data File 20160607 contains the same 
version.

How to check which CPUs or instructions are affected?

Regards,
  Michael!

On 7/19/2016 1:40 PM, Torbjörn Granlund wrote:
> Michael Fuckner <michael at fuckner.net> writes:
>
>   I am using Fedora24 (umgraded from 23) on Intel G3900 (Skylake) and
>   try to compile fdk-aac. Any help appreciated!
>
> [snip]
>
>   libAACdec/src/aacdec_drc.cpp:137:3: internal compiler error: Illegal
>   instruction
>      pParams->cut      = FL2FXCONST_DBL(0.0f);
>      ^~~~~~~
>
> [snip]
>
>   in dmesg I see (that's why I believe this problem is related to gmp):
>   [87398.237931] traps: expr[13570] trap invalid opcode ip:7f542d3efa1b
>   sp:7ffc3d9c3fe8 error:0 in libgmp.so.10.3.0[7f542d3b5000+92000]
>
> I think this is really a problem with the chip, that CPUID claims
> support for instructions which are actually clobbered with silicon
> fuses.
>
> A BIOS upgrade might fix this, as BIOS can patch instructions like
> CPUID.  Also, upgrading to GMP 6.1.1 should help, as we there blacklist
> known faulty Intel chips.
>