On Mon, Jun 22, 2020 at 11:10:10PM -0700, [email protected] wrote: > Are SSE instructions allowed in the AMD64 kernel? Is #ifdef __SSE__ > a sufficient guard? > > I have a rasops32 putchar with SSE that is 2x faster.
No, in general you cannot using FP instructions in the kernel, also the kernel is often compiled with -msoft-float on platforms that support it.
