[Interest] Callgrind under Linux

Thiago Macieira thiago.macieira at intel.com
Sat Mar 7 16:57:47 CET 2020

On Friday, 6 March 2020 08:54:48 PST Giuseppe D'Angelo via Interest wrote:
> Il 06/03/20 15:56, Konstantin Tokarev ha scritto:
> >> We did find a closed issue about
> >> it:https://bugreports.qt.io/browse/QTBUG-62118 But no solution or hint
> >> about the cause of this.
> > 
> > You can configure Qt with explicitly disable RDRAND, or use same hack as
> > used in tst_qrandomgenerator.cpp, passing SkipHWRNG flag to
> > qt_randomdevice_control.
> Or just export QT_NO_CPU_FEATURE=rdrnd , no need to rebuild Qt (RDRAND
> is detected at runtime).

(unless you compiled with -mrdrnd [usually through -march=], in which case it 
as detected at compile time and you CANNOT disable it)

Better yet: upgrade valgrind. It can handle RDRAND just fine now.

Though it doesn't support RDSEED yet, which we added in Qt 5.15.

Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel System Software Products

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