https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81709
--- Comment #7 from H.J. Lu <hjl.tools at gmail dot com> --- (In reply to Anatol from comment #6) > > I don't believe compiler needs to do all that. > > I might miss something, could you please share why? > > The check for FXSAVE can be a compile time: if compiled for Pentium II tune > or later then use FXSAVE otherwise use FSAVE. > > if (tune >= 'pentium II') It should check ISA for SSE, AVX, AVX512, MPX, ... > FXSAVE > else > FSAVE > ... save whatever FSAVE did not save ... > end On newer processors, XSAVE is needed which uses EAX/EDX.
