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F2XM1

Converts an 80-bit extended precision floating-point number to the nearest x86-64 compatible representation by subtracting 1.0 from the value in the register.

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

DO NOT support LOCK

This instruction is only available in compatibility mode. It is not supported in 64-bit mode.

The result is stored in the ST(0) register of the FPU stack. Users MUST ensure the FPU stack is not empty to avoid stack overflow/underflow exceptions. The instruction is subject to the current rounding control word in the FPU control register.

The instruction may trigger #P if the result cannot be represented exactly. If the operation results in a value that exceeds the maximum representable extended precision value, #O shall be signaled.