mirror of
https://github.com/WangXuan95/USTC-RVSoC.git
synced 2025-01-30 23:02:55 +08:00
54 lines
1.8 KiB
ArmAsm
54 lines
1.8 KiB
ArmAsm
.org 0x0
|
||
.global _start
|
||
_start:
|
||
addi zero, zero, 0x123
|
||
addi zero, zero, 0x456
|
||
|
||
lui sp, 0x00010
|
||
ori sp, sp, 0x400 # stack pointer=0x400, stack size = 256 dwords
|
||
|
||
xori t0, zero, 6 # t0 = 6
|
||
jal ra, fibonacci_recursive
|
||
|
||
xori a1, t1, 0 # 计算完成，结果在t1中，闲着没事干把它放到a1里好了
|
||
jal zero, program_end # 跳到死循环程序
|
||
|
||
fibonacci_recursive: # 递归计算斐波那契数列的第n项，
|
||
# n放在t0寄存器中
|
||
# 结果放在t1寄存器中
|
||
# 使用ra作为返回地址，并使用堆栈，堆栈指针为sp
|
||
|
||
ori a0, zero, 3 # a0 = 3
|
||
bgeu t0, a0, tag # if t0>=a0(3), jmp to tag
|
||
ori t1, t0, 0 # t1 = t0
|
||
jalr zero, ra, 0 # pc = ra
|
||
|
||
tag:
|
||
addi sp, sp, -4 # sp-=4 # push ra to stack
|
||
sw ra, (sp) # mem[sp] = ra
|
||
|
||
addi t0, t0, -1 # t0-=1
|
||
addi sp, sp, -4 # sp-=4 # push t0 to stack
|
||
sw t0, (sp) # mem[sp] = t0
|
||
|
||
jal ra, fibonacci_recursive # fibonacci_recursive n-1
|
||
|
||
lw t0, 0(sp) # t0=mem[sp] # pop t0 from stack
|
||
addi sp, sp, 4 # sp+=4
|
||
addi t0, t0, -1 # t0-=1
|
||
|
||
addi sp, sp, -4 # sp-=4 # push t1 to stack
|
||
sw t1, (sp) # mem[sp] = t1
|
||
jal ra, fibonacci_recursive # fibonacci_recursive n-2
|
||
lw t2, 0(sp) # ra=mem[sp] # pop t2 from stack
|
||
addi sp, sp, 4 # sp+=4
|
||
add t1, t1, t2 # t1+=t2
|
||
|
||
lw ra, 0(sp) # ra=mem[sp] # pop ra from stack
|
||
addi sp, sp, 4 # sp+=4
|
||
|
||
jalr zero, ra,0 # pc = ra
|
||
|
||
program_end:
|
||
jal zero, program_end # infinity loop
|
||
|