fmuls
Multiplication of two f32s is the single-precision fmuls:
fmuls f1, f1, f2 # f1 = a * b
blr
Unlike the integer world there is no "multiply low / multiply high" split and no immediate form — floating-point multiply is one clean instruction. The trailing s is the tell that the operands and result are 32-bit single precision rather than 64-bit double.
Your task
Write mul_f to match the fmuls above.