ORN - RISC-V instruction reference

ornOR with inverted operand 
Sets t1 to the bitwise OR of t2 and the bitwise NOT of t3.
RISC-V manual: orn 
Forms  orn , ,   
Operands t1 Any integer register, x0 to x31, or its named alias, such as zero, t0 or t6. 
t2 An integer register. It may be the same register as t1. 
t3 An integer register. It may be the same register as t1. 
 .text
li t0, 13
li t1, 5
# t0=13, t1=5; orn writes -1 (0xFFFFFFFF) to t2.
orn t2, t0, t1