1 files changed, 65 insertions, 0 deletions
diff --git a/src/shifter.rs b/src/shifter.rs
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+++ b/src/shifter.rs
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+/*
+	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 std::fmt::{Display, Formatter};
+
+mod extract;
+
+#[derive(Clone, Copy)]
+pub enum Shifter {
+	Immediate(                    u8, u8),
+	ArithmeticShiftRightImmediate(u8, u8),
+	ArithmeticShiftRightRegister( u8, u8),
+	LogicalShiftLeftImmediate(    u8, u8),
+	LogicalShiftLeftRegister(     u8, u8),
+	LogicalShiftRightImmediate(   u8, u8),
+	LogicalShiftRightRegister(    u8, u8),
+	RotateRightImmediate(         u8, u8),
+	RotateRightRegister(          u8, u8),
+	RotateRightExtend(            u8),
+}
+
+impl Shifter {
+	#[inline(always)]
+	pub const fn from_register(register: u8) -> Shifter { Shifter::LogicalShiftLeftImmediate(register, 0x0) }
+}
+
+impl Display for Shifter {
+	#[must_use]
+	fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+		use Shifter::*;
+
+		return match *self {
+			Immediate(                    imm, rot) => write!(f, "#{:#X}", (imm as u32).rotate_right(rot as u32)),
+			ArithmeticShiftRightImmediate(rm, imm)  => write!(f, "r{rm}, ASR #{imm:#X}"),
+			ArithmeticShiftRightRegister( rm, rs)   => write!(f, "r{rm}, ASR r{rs}"),
+			LogicalShiftLeftImmediate(    rm, imm)  => write!(f, "r{rm}, LSL #{imm:#X}"),
+			LogicalShiftLeftRegister(     rm, rs)   => write!(f, "r{rm}, LSL r{rs}"),
+			LogicalShiftRightImmediate(   rm, imm)  => write!(f, "r{rm}, LSR #{imm:#X}"),
+			LogicalShiftRightRegister(    rm, rs)   => write!(f, "r{rm}, LSR r{rs}"),
+			RotateRightImmediate(         rm, imm)  => write!(f, "r{rm}, ROR #{imm:#X}"),
+			RotateRightRegister(          rm, rs)   => write!(f, "r{rm}, ROR r{rs}"),
+			RotateRightExtend(            rm)       => write!(f, "RXX"),
+		};
+	}
+}