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FSQRT

Computes the square root of an f80-bit floating-point value stored in the ST(0) register and stores the result in the ST(0) register.

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

DO NOT support LOCK

This instruction is available in 64-bit mode only when executing in compatibility mode. It operates exclusively on the x87 Floating-Point Unit (FPU) register stack.

The input value MUST be a non-negative f80. If the input is a Negative NaN or a negative number, the instruction SHALL signal the Invalid Operation exception (#I) and store a QNaN in ST(0). If the input is a Zero, the result is Zero. Denormalized operands SHALL trigger the Denormalized operand exception (#D). Precision (#P) is signaled if the result cannot be represented exactly in the f80 format.