CLK/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm

//
//  ARMDecoderTests.m
//  Clock Signal
//
//  Created by Thomas Harte on 16/02/2024.
//  Copyright 2024 Thomas Harte. All rights reserved.
//

#import <XCTest/XCTest.h>

#include "../../../InstructionSets/ARM/Executor.hpp"

using namespace InstructionSet::ARM;

namespace {

struct Memory {
	template <typename IntT>
	bool write(uint32_t address, IntT source, Mode mode, bool trans) {
		(void)address;
		(void)source;
		(void)mode;
		(void)trans;
		return true;
	}

	template <typename IntT>
	bool read(uint32_t address, IntT &source, Mode mode, bool trans) {
		(void)address;
		(void)source;
		(void)mode;
		(void)trans;
		return true;
	}
};

}

@interface ARMDecoderTests : XCTestCase
@end

@implementation ARMDecoderTests

//- (void)testXYX {
//	Executor<Memory> scheduler;
//
//	for(int c = 0; c < 65536; c++) {
//		InstructionSet::ARM::dispatch(c << 16, scheduler);
//	}
//	InstructionSet::ARM::dispatch(0xEAE06900, scheduler);
//}

- (void)testBarrelShifterLogicalLeft {
	uint32_t value;
	uint32_t carry;

	// Test a shift by 1 into carry.
	value = 0x8000'0000;
	shift<ShiftType::LogicalLeft, true>(value, 1, carry);
	XCTAssertEqual(value, 0);
	XCTAssertNotEqual(carry, 0);

	// Test a shift by 18 into carry.
	value = 0x0000'4001;
	shift<ShiftType::LogicalLeft, true>(value, 18, carry);
	XCTAssertEqual(value, 0x4'0000);
	XCTAssertNotEqual(carry, 0);

	// Test a shift by 17, not generating carry.
	value = 0x0000'4001;
	shift<ShiftType::LogicalLeft, true>(value, 17, carry);
	XCTAssertEqual(value, 0x8002'0000);
	XCTAssertEqual(carry, 0);
}

- (void)testBarrelShifterLogicalRight {
	uint32_t value;
	uint32_t carry;

	// Test successive shifts by 4; one generating carry and one not.
	value = 0x12345678;
	shift<ShiftType::LogicalRight, true>(value, 4, carry);
	XCTAssertEqual(value, 0x1234567);
	XCTAssertNotEqual(carry, 0);

	shift<ShiftType::LogicalRight, true>(value, 4, carry);
	XCTAssertEqual(value, 0x123456);
	XCTAssertEqual(carry, 0);

	// Test shift by 1.
	value = 0x8003001;
	shift<ShiftType::LogicalRight, true>(value, 1, carry);
	XCTAssertEqual(value, 0x4001800);
	XCTAssertNotEqual(carry, 0);

	// Test a shift by greater than 32.
	value = 0xffff'ffff;
	shift<ShiftType::LogicalRight, true>(value, 33, carry);
	XCTAssertEqual(value, 0);
	XCTAssertEqual(carry, 0);

	// Test shifts by 32: result is always 0, carry is whatever was in bit 31.
	value = 0xffff'ffff;
	shift<ShiftType::LogicalRight, true>(value, 32, carry);
	XCTAssertEqual(value, 0);
	XCTAssertNotEqual(carry, 0);

	value = 0x7fff'ffff;
	shift<ShiftType::LogicalRight, true>(value, 32, carry);
	XCTAssertEqual(value, 0);
	XCTAssertEqual(carry, 0);

	// Test that a logical right shift by 0 is the same as a shift by 32.
	value = 0xffff'ffff;
	shift<ShiftType::LogicalRight, true>(value, 0, carry);
	XCTAssertEqual(value, 0);
	XCTAssertNotEqual(carry, 0);
}

- (void)testBarrelShifterArithmeticRight {
	uint32_t value;
	uint32_t carry;

	// Test a short negative shift.
	value = 0x8000'0030;
	shift<ShiftType::ArithmeticRight, true>(value, 1, carry);
	XCTAssertEqual(value, 0xc000'0018);
	XCTAssertEqual(carry, 0);

	// Test a medium negative shift without carry.
	value = 0xffff'0000;
	shift<ShiftType::ArithmeticRight, true>(value, 11, carry);
	XCTAssertEqual(value, 0xffff'ffe0);
	XCTAssertEqual(carry, 0);

	// Test a medium negative shift with carry.
	value = 0xffc0'0000;
	shift<ShiftType::ArithmeticRight, true>(value, 23, carry);
	XCTAssertEqual(value, 0xffff'ffff);
	XCTAssertNotEqual(carry, 0);

	// Test a long negative shift.
	value = 0x8000'0000;
	shift<ShiftType::ArithmeticRight, true>(value, 32, carry);
	XCTAssertEqual(value, 0xffff'ffff);
	XCTAssertNotEqual(carry, 0);

	// Test a positive shift.
	value = 0x0123'0031;
	shift<ShiftType::ArithmeticRight, true>(value, 3, carry);
	XCTAssertEqual(value, 0x24'6006);
	XCTAssertEqual(carry, 0);
}

- (void)testBarrelShifterRotateRight {
	uint32_t value;
	uint32_t carry;

	// Test a short rotate by one hex digit.
	value = 0xabcd'1234;
	shift<ShiftType::RotateRight, true>(value, 4, carry);
	XCTAssertEqual(value, 0x4abc'd123);
	XCTAssertEqual(carry, 0);

	// Test a longer rotate, with carry.
	value = 0xa5f9'6342;
	shift<ShiftType::RotateRight, true>(value, 17, carry);
	XCTAssertEqual(value, 0xb1a1'52fc);
	XCTAssertNotEqual(carry, 0);

	// Test a rotate by 32 without carry.
	value = 0x385f'7dce;
	shift<ShiftType::RotateRight, true>(value, 32, carry);
	XCTAssertEqual(value, 0x385f'7dce);
	XCTAssertEqual(carry, 0);

	// Test a rotate by 32 with carry.
	value = 0xfecd'ba12;
	shift<ShiftType::RotateRight, true>(value, 32, carry);
	XCTAssertEqual(value, 0xfecd'ba12);
	XCTAssertNotEqual(carry, 0);

	// Test a rotate through carry, carry not set.
	value = 0x123f'abcf;
	carry = 0;
	shift<ShiftType::RotateRight, true>(value, 0, carry);
	XCTAssertEqual(value, 0x091f'd5e7);
	XCTAssertNotEqual(carry, 0);

	// Test a rotate through carry, carry set.
	value = 0x123f'abce;
	carry = 1;
	shift<ShiftType::RotateRight, true>(value, 0, carry);
	XCTAssertEqual(value, 0x891f'd5e7);
	XCTAssertEqual(carry, 0);
}

@end