https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81709
--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> --- (In reply to Anatol from comment #2) > Theoretically it is possible to do things like this manually. Track > functions x86 extensions usage and save registers accordingly. But I would > love to see a more automated and less error-prone way to do it. Similar to > what CLANG compiler already does. CLANG tracks registers use and reduces a > lot of burden for me. > > That is the reason why we switched to CLANG in our project for now but I > would love to see GCC first-class support as well. > > What is the reason that GCC does not track SSE register usage? Is it a GGC > architecture restriction or something else? To use SSE registers in interrupt handler, you need to save the complete vector state, %xmm0-%xmm15 isn't sufficient. You need to preserve the whole set of vector registers plus MXCSR register. One way to do it is to use xsave/xrstor.
