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[decoder] fixed bug when decoding add/sub instruction

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This commit is contained in:
Anton Lydike 2021-06-05 15:24:40 +02:00
parent 849d5f4fc3
commit 3e4920f5d9
1 changed files with 12 additions and 16 deletions
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28
riscemu/decoder/decoder.py
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@ -39,16 +39,16 @@ def name_from_insn(ins: int):
if isinstance(dec, str):
return dec
fun = funct3(ins)
if fun not in dec:
fun3 = funct3(ins)
if fun3 not in dec:
print_ins(ins)
raise RuntimeError(f"Invalid funct3: {fun:0x} in insn {ins:x}")
raise RuntimeError(f"Invalid funct3: {fun3:0x} in insn {ins:x}")
dec = dec[fun]
dec = dec[fun3]
if isinstance(dec, str):
return dec
if opcode == 0x1c and fun == 0:
if opcode == 0x1c and fun3 == 0:
# we have ecall/ebreak
token = imm110(ins)
if token in dec:
@ -56,17 +56,13 @@ def name_from_insn(ins: int):
print_ins(ins)
raise RuntimeError(f"Invalid instruction in ebreak/ecall region: {ins:x}")
fun = funct7(ins)
if fun in dec:
if opcode == 0x0C or (opcode == 0x04 and fun == 5):
mode = imm110(ins)
dec = dec[fun]
if mode in dec:
return dec[mode]
print_ins(ins)
raise RuntimeError("Unknown instruction!")
return dec[fun]
fun7 = funct7(ins)
if fun7 in dec:
if opcode == 0x0C or (opcode == 0x04 and fun3 == 5):
dec = dec[fun7]
return dec
print("unknown instruction?!")
return dec[fun7]
print_ins(ins)
raise RuntimeError(f"Invalid instruction: {ins:x}")