/*
Copyright 2021-2023 Gabriel Jensen.
This file is part of Luma.
Luma is free software: you can redistribute it
and/or modify it under the terms of the GNU
Affero General Public License as published by
the Free Software Foundation, either version 3
of the License, or (at your option) any later
version.
Luma is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU
Affero General Public License along with Luma.
If not, see <https://www.gnu.org/licenses/>.
*/
use crate::shifter::Shifter;
use crate::state::State;
impl State {
#[must_use]
pub fn shifter_value(&self, shifter: Shifter) -> (u32, bool) {
use Shifter::*;
let c = self.read_cpsr() & 0b00100000000000000000000000000000 != 0x0;
let (value, carry) = match shifter {
Immediate(imm, rot) => {
let result = (imm as u32).rotate_right(rot as u32);
let c = if rot == 0x0 { c } else { result & 0b10000000000000000000000000000000 != 0x0 };
(result, c)
},
ArithmeticShiftRightImmediate(rm, imm) => {
let rm_value = self.read_register(rm);
let result = (rm_value as i32).wrapping_shr(imm as u32) as u32;
let c = false; // TODO
(result, c)
},
ArithmeticShiftRightRegister(rm, rs) => {
let rm_value = self.read_register(rm);
let rs_value = self.read_register(rs);
let result = (rm_value as i32).wrapping_shr(rs_value) as u32;
let c = false; // TODO
(result, c)
},
LogicalShiftLeftImmediate(rm, imm) => {
let rm_value = self.read_register(rm);
let result = rm_value.wrapping_shl(imm as u32);
let c = false; // TODO
(result, c)
},
LogicalShiftLeftRegister(rm, rs) => {
let rm_value = self.read_register(rm);
let rs_value = self.read_register(rs);
let result = rm_value.wrapping_shl(rs_value);
let c = false; // TODO
(result, c)
},
LogicalShiftRightImmediate(rm, imm) => {
let rm_value = self.read_register(rm);
let result = rm_value.wrapping_shr(imm as u32);
let c = false; // TODO
(result, c)
},
LogicalShiftRightRegister(rm, rs) => {
let rm_value = self.read_register(rm);
let rs_value = self.read_register(rs);
let result = rm_value.wrapping_shr(rs_value);
let c = false; // TODO
(result, c)
},
RotateRightImmediate(rm, imm) => {
let rm_value = self.read_register(rm);
let result = rm_value.rotate_right(imm as u32);
let c = false; // TODO
(result, c)
},
RotateRightRegister(rm, rs) => {
let rm_value = self.read_register(rm);
let rs_value = self.read_register(rs);
let result = rm_value.rotate_right(rs_value);
let c = false; // TODO
(result, c)
},
RotateRightExtend(rm) => {
let rm_value = self.read_register(rm);
let result = 0x0_u32; // TODO
let c = rm_value & 0b00000000000000000000000000000001 != 0x0;
(result, c)
},
};
return (value, carry);
}
}
