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EMMS

Sets the FPU tag word to 0, effectively emptying the FPU register stack.

The following table covers what the source and destinations can be.

DO NOT support LOCK

The instruction is supported in 64-bit mode and compatibility mode. It specifically affects the x87 FSTK (Floating-Point Stack) state.

Failure to execute EMMS after using FPU instructions in a mixed-mode environment MAY lead to FPU stack overflow exceptions if the stack pointer (TOP) is not reset before subsequent FPU operations. This is critical when interfacing with legacy code or libraries that expect a clean FPU stack.