fsd
Floating-Point Store Double-Precision
The fsd instruction stores a double-precision value from the floating-point registers to memory. It is guaranteed to execute atomically if the effective address is naturally aligned and XLEN≥64. It doesn’t modify the bits being transferred; in particular, the payloads of non-canonical NaNs are preserved.
Decode Variables
signed Bits<12> imm = sext({$encoding[31:25], $encoding[11:7]}, 12);
Bits<5> fs2 = $encoding[24:20];
Bits<5> xs1 = $encoding[19:15];