diff options
| -rw-r--r-- | src/instructions.rs | 1 | ||||
| -rw-r--r-- | src/instructions/rvi.rs | 10 |
2 files changed, 11 insertions, 0 deletions
diff --git a/src/instructions.rs b/src/instructions.rs index 6e9fbd8..615dd7a 100644 --- a/src/instructions.rs +++ b/src/instructions.rs @@ -16,6 +16,7 @@ pub(crate) fn find_and_exec(instr: Instruction, core: &mut Core) -> Option<Instr 0b01100 => match (instr.funct7(), instr.funct3()) { // OP (0b0000000, 0b000) => Some(rvi::add(core, instr)), + (0b0100000, 0b000) => Some(rvi::sub(core, instr)), (0b0000000, 0b111) => Some(rvi::and(core, instr)), (0b0000000, 0b110) => Some(rvi::or(core, instr)), _ => None, diff --git a/src/instructions/rvi.rs b/src/instructions/rvi.rs index 69670d0..df3d9d5 100644 --- a/src/instructions/rvi.rs +++ b/src/instructions/rvi.rs @@ -21,6 +21,16 @@ pub fn add(core: &mut Core, instr: Instruction) -> InstructionResult { InstructionResult::Normal } +pub fn sub(core: &mut Core, instr: Instruction) -> InstructionResult { + core.reg_write( + instr.rd(), + core.reg_read(instr.rs1()) + .wrapping_sub(core.reg_read(instr.rs2())), + ); + core.advance_pc(); + InstructionResult::Normal +} + pub fn addi(core: &mut Core, instr: Instruction) -> InstructionResult { core.reg_write( instr.rd(), |