FRSR: RISC-V instruction reference

frsrRead FP control and status register Pseudo-instruction
Reads the FP control and status register into a register, as an alias of frcsr.
RISC-V manual: csrrs 
Forms  frsr   
Same as frcsr t1.
Operands t1 Any integer register, x0 to x31, or its named alias, such as zero, t0 or t6. 
 # Initialize fcsr, then use frsr to read its old value or update it.
.text
li t3, 0
csrw t3, fcsr
frsr t1
# t1=0 because fcsr was cleared immediately above.