From c865da67e0bf8f15d803ab1a9caf50b48a0a984f Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 2 Mar 2024 15:12:03 -0500
Subject: [PATCH] Introduce further barrel-shifter tests.

---
 .../Mac/Clock SignalTests/ARMDecoderTests.mm  | 101 ++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm b/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm
index dc96c0ccf..352de1907 100644
--- a/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm	
@@ -50,6 +50,29 @@ struct Memory {
 //	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;
@@ -94,4 +117,82 @@ struct Memory {
 	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