1111101111111101
Available only when PR=0
sr ← ZeroExtend32(SR);
fr ← ZeroExtend1(FPSCR.FR);
IF (FpuIsDisabled(sr) AND IsDelaySlot())
THROW SLOTFPUDIS;
IF (FpuIsDisabled(sr))
THROW FPUDIS;
fr ← fr ⊕ 1;
FPSCR.FR ← Bit(fr);