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FCHS

Changes the sign of the floating-point value in the destination operand to positive.

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

DO NOT support LOCK

This instruction is available in both 32-bit and 64-bit modes. It operates exclusively on the x87 FPU register stack.

The instruction modifies the sign bit of the floating-point representation to 0. It SHALL NOT affect the exponent or the significand of the operand. No floating-point exceptions are generated.