[decoder] removed sign extension for CSR type instructions

3 years ago · 639f91b192
parent c25b9f2343
commit 639f91b192
1 changed files with 5 additions and 1 deletions
--- a/riscemu/decoder/formats.py
+++ b/riscemu/decoder/formats.py
@ -98,6 +98,10 @@ def decode_i_shamt(ins: int) -> List[int]:
    return decode_i(ins)


+def decode_i_unsigned(ins: int) -> List[int]:
+    return [rd(ins), rs1(ins), imm110(ins)]
+
+
 INSTRUCTION_ARGS_DECODER: Dict[int, Callable[[int], List[int]]] = {
    0x00: decode_i,
    0x04: decode_i_shamt,
@ -108,5 +112,5 @@ INSTRUCTION_ARGS_DECODER: Dict[int, Callable[[int], List[int]]] = {
    0x18: decode_b,
    0x19: decode_i,
    0x1b: decode_j,
-    0x1c: decode_i
+    0x1c: decode_i_unsigned
 }