Fully implement B-types (1f51d4dd) · Commits · John Jekel / legv8

src/legv8assemble.rs

+19 −1

Original line number	Diff line number	Diff line
		@@ -350,6 +350,8 @@ fn assemble(instruction_string: &str) -> Option<(InstructionType, u32)> {
		}
		}

		//Determine register fields

		//Determine Rd/Rt/neither depending on the instruction type
		match instruction_type {
		InstructionType::R \| InstructionType::I \| InstructionType::D \| InstructionType::CB \| InstructionType::IM => {
		@@ -387,6 +389,8 @@ fn assemble(instruction_string: &str) -> Option<(InstructionType, u32)> {
		}
		}

		//Determine immediate fields

		//Determine the immediate/address to use from the 4th token depending on the instruction_type
		match instruction_type {
		InstructionType::I => {
		@@ -395,6 +399,8 @@ fn assemble(instruction_string: &str) -> Option<(InstructionType, u32)> {
		return None;
		}
		instruction.set_bits(immediate, 21, 10);
		} else {
		return None;
		}
		},
		InstructionType::D => {
		@@ -403,12 +409,24 @@ fn assemble(instruction_string: &str) -> Option<(InstructionType, u32)> {
		return None;
		}
		instruction.set_bits(address, 20, 12);
		} else {
		return None;
		}
		},
		InstructionType::R \| InstructionType::CB \| InstructionType::IM \| InstructionType::B => {}//They do not have this field
		}

		//TODO other fields
		//Determine the branch address to use from the second token if the instruction type is B
		if matches!(instruction_type, InstructionType::B) {
		if let Some(address) = smart_parse_uint(tokens[1]) {
		if address > 0b11111111111111111111111111 {//Too large for the field to hold
		return None;
		}
		instruction.set_bits(address, 25, 0);
		} else {
		return None;
		}
		}

		return Some((instruction_type, instruction));
		}