https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92597
--- Comment #6 from Klaus Leppkes <leppkes at stce dot rwth-aachen.de> --- As it might be purely related to google benchmark, I opened an issues for google benchmark citing this bug report: https://github.com/google/benchmark/issues/903 I search for some doc and found "g" : Any register, memory or immediate integer operand is allowed, except for registers that are not general registers." (x86 specified!). vs. "m" : A memory operand is allowed, with any kind of address that the machine supports in general. source: https://www.ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html So I tend to thing the code should be modified on google benchmark in case of using x86 machines.