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use crate::{
consts::{Addr, DWord},
core::{Core, InstructionResult},
decode::Instruction,
instructions::{
OpcodeHandler,
gen_tools::insert_funct3_splitter,
opcodes::{FUNCT3_ADDI, FUNCT3_SD, OP_IMM, STORE},
},
mem::PageNum,
};
pub(super) fn add_instrs(list: &mut [OpcodeHandler; 32]) {
let funct3_split_op_imm = insert_funct3_splitter(&mut list[OP_IMM as usize].splitter);
funct3_split_op_imm[FUNCT3_ADDI as usize].handler =
Some(super::InstructionHandler { runner: addi });
let funct3_split_store = insert_funct3_splitter(&mut list[STORE as usize].splitter);
funct3_split_store[FUNCT3_SD as usize].handler = Some(super::InstructionHandler { runner: sd })
}
fn addi(core: &mut Core, instr: Instruction) -> InstructionResult {
core.reg_write(
instr.rd(),
core.reg_read(instr.rs1()).wrapping_add(instr.imm_i()),
);
core.pc = core.pc.wrapping_add(4);
InstructionResult::Normal
}
fn sd(core: &mut Core, instr: Instruction) -> InstructionResult {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_s());
if !addr.is_multiple_of(std::mem::size_of::<DWord>() as Addr) {
return InstructionResult::Exception(());
}
let page = (addr / 4096) as PageNum;
let offset = (addr & ((4096 / std::mem::size_of::<DWord>() as Addr) - 1)) as u16;
let value = core.reg_read(instr.rs2());
match core.mem.write_dword(page, offset, value) {
Ok(_) => {
core.pc = core.pc.wrapping_add(4);
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
}
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