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// Copyright (c) 2025 taitep
// SPDX-License-Identifier: MIT
//
// This file is part of TRVE (https://gitea.taitep.se/taitep/trve)
// See LICENSE file in the project root for full license text.
mod rvi;
use crate::{
core::Core,
decode::Instruction,
exceptions::ExceptionType::{self, IllegalInstruction},
};
pub(crate) fn find_and_exec(instr: Instruction, core: &mut Core) -> Result<(), ExceptionType> {
match instr.opcode_noncompressed() {
0b01100 => match (instr.funct7(), instr.funct3()) {
// OP
(0b0000000, 0b000) => rvi::add(core, instr),
(0b0100000, 0b000) => rvi::sub(core, instr),
(0b0000000, 0b111) => rvi::and(core, instr),
(0b0000000, 0b110) => rvi::or(core, instr),
_ => Err(IllegalInstruction),
},
0b00100 => match instr.funct3() {
// OP_IMM
0b000 => rvi::addi(core, instr),
0b001 => {
if instr.funct6() == 0 {
rvi::slli(core, instr)
} else {
Err(IllegalInstruction)
}
}
0b101 => match instr.funct6() {
// immediate right-shift
0b000000 => rvi::srli(core, instr),
_ => Err(IllegalInstruction),
},
0b111 => rvi::andi(core, instr),
_ => Err(IllegalInstruction),
},
0b00110 => match instr.funct3() {
// OP_IMM_32
0b000 => rvi::addiw(core, instr),
_ => Err(IllegalInstruction),
},
0b01000 => match instr.funct3() {
// STORE
0b000 => rvi::sb(core, instr),
0b001 => rvi::sh(core, instr),
0b010 => rvi::sw(core, instr),
0b011 => rvi::sd(core, instr),
_ => Err(IllegalInstruction),
},
0b00000 => match instr.funct3() {
// LOAD
0b000 => rvi::lb(core, instr),
0b100 => rvi::lbu(core, instr),
0b001 => rvi::lh(core, instr),
0b101 => rvi::lhu(core, instr),
0b010 => rvi::lw(core, instr),
0b110 => rvi::lwu(core, instr),
0b011 => rvi::ld(core, instr),
_ => Err(IllegalInstruction),
},
0b11000 => match instr.funct3() {
// BRANCH
0b000 => rvi::beq(core, instr),
0b001 => rvi::bne(core, instr),
0b100 => rvi::blt(core, instr),
0b110 => rvi::bltu(core, instr),
0b111 => rvi::bgeu(core, instr),
_ => Err(IllegalInstruction),
},
0b01101 => rvi::lui(core, instr),
0b00101 => rvi::auipc(core, instr),
0b11011 => rvi::jal(core, instr),
0b11001 => {
if instr.funct3() == 0 {
rvi::jalr(core, instr)
} else {
Err(IllegalInstruction)
}
}
_ => Err(IllegalInstruction),
}
}
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