RISCV

Register

5-bit Encoding (rx)	3-bit Compressed Encoding (rx’)	Register	ABI Name	Description	Saved by Calle-
0	-	x0	zero	hardwired zero	-
1	-	x1	ra	return address	-R
2	-	x2	sp	stack pointer	-E
3	-	x3	gp	global pointer	-
4	-	x4	tp	thread pointer	-
5	-	x5	t0	temporary register 0	-R
6	-	x6	t1	temporary register 1	-R
7	-	x7	t2	temporary register 2	-R
8	0	x8	s0 / fp	saved register 0 / frame pointer	-E
9	1	x9	s1	saved register 1	-E
10	2	x10	a0	function argument 0 / return value 0	-R
11	3	x11	a1	function argument 1 / return value 1	-R
12	4	x12	a2	function argument 2	-R
13	5	x13	a3	function argument 3	-R
14	6	x14	a4	function argument 4	-R
15	7	x15	a5	function argument 5	-R
16	-	x16	a6	function argument 6	-R
17	-	x17	a7	function argument 7	-R
18	-	x18	s2	saved register 2	-E
19	-	x19	s3	saved register 3	-E
20	-	x20	s4	saved register 4	-E
21	-	x21	s5	saved register 5	-E
22	-	x22	s6	saved register 6	-E
23	-	x23	s7	saved register 7	-E
24	-	x24	s8	saved register 8	-E
25	-	x25	s9	saved register 9	-E
26	-	x26	s10	saved register 10	-E
27	-	x27	s11	saved register 11	-E
28	-	x28	t3	temporary register 3	-R
29	-	x29	t4	temporary register 4	-R
30	-	x30	t5	temporary register 5	-R
31	-	x31	t6	temporary register 6	-R