add binary rm-r operations

This commit is contained in:
David Gonzalez Martin 2023-07-12 09:04:58 -06:00
parent 29097ca1e4
commit 931e60e37e

View File

@ -11,19 +11,29 @@ const Section = struct {
};
const Image = struct {
text: Section,
rodata: Section,
data: Section,
sections: struct {
text: Section,
rodata: Section,
data: Section,
},
entry_point: u32 = 0,
fn create() !Image {
return Image{
.text = .{ .content = try mmap(page_size, .{ .executable = true }) },
.rodata = .{ .content = try mmap(page_size, .{ .executable = false }) },
.data = .{ .content = try mmap(page_size, .{ .executable = false }) },
.sections = .{
.text = .{ .content = try mmap(page_size, .{ .executable = true }) },
.rodata = .{ .content = try mmap(page_size, .{ .executable = false }) },
.data = .{ .content = try mmap(page_size, .{ .executable = false }) },
},
};
}
fn destroy(image: *Image) void {
inline for (comptime std.meta.fieldNames(@TypeOf(image.sections))) |field_name| {
std.os.munmap(@field(image.sections, field_name).content);
}
}
inline fn mmap(size: usize, flags: packed struct {
executable: bool,
}) ![]align(page_size) u8 {
@ -34,9 +44,14 @@ const Image = struct {
}
fn appendCode(image: *Image, code: []const u8) void {
const destination = image.text.content[image.text.index..][0..code.len];
const destination = image.sections.text.content[image.sections.text.index..][0..code.len];
@memcpy(destination, code);
image.text.index += code.len;
image.sections.text.index += code.len;
}
fn appendCodeByte(image: *Image, code_byte: u8) void {
image.sections.text.content[image.sections.text.index] = code_byte;
image.sections.text.index += 1;
}
fn getEntryPoint(image: *const Image, comptime Function: type) *const Function {
@ -44,8 +59,8 @@ const Image = struct {
assert(@typeInfo(Function) == .Fn);
}
assert(image.text.content.len > 0);
return @as(*const Function, @ptrCast(&image.text.content[image.entry_point]));
assert(image.sections.text.content.len > 0);
return @as(*const Function, @ptrCast(&image.sections.text.content[image.entry_point]));
}
};
@ -77,13 +92,24 @@ const GPRegister = enum(u4) {
r15 = 15,
};
pub const BasicGPRegister = enum(u3) {
a = 0,
c = 1,
d = 2,
b = 3,
sp = 4,
bp = 5,
si = 6,
di = 7,
};
const prefix_lock = 0xf0;
const prefix_repne_nz = 0xf2;
const prefix_rep = 0xf3;
const prefix_rex_w = [1]u8{@intFromEnum(Rex.w)};
const prefix_16_bit_operand = [1]u8{0x66};
const ret = [1]u8{0xc3};
const ret = 0xc3;
const mov_a_imm = [1]u8{0xb8};
const mov_reg_imm8: u8 = 0xb0;
@ -95,36 +121,21 @@ inline fn intToArrayOfBytes(integer: anytype) [@sizeOf(@TypeOf(integer))]u8 {
return @as([@sizeOf(@TypeOf(integer))]u8, @bitCast(integer));
}
fn movToAInstructionByteCount(comptime bit_count: u16) type {
return [
switch (bit_count) {
8 => 2,
16 => 4,
32 => 5,
64 => 10,
else => @compileError("Not supported"),
}
]u8;
}
inline fn movAImm(comptime signedness: std.builtin.Signedness, comptime bit_count: u16, integer: @Type(.{
.Int = .{
.signedness = signedness,
.bits = bit_count,
},
})) movToAInstructionByteCount(bit_count) {
return switch (@TypeOf(integer)) {
inline fn movAImm(image: *Image, integer: anytype) void {
const T = @TypeOf(integer);
image.appendCode(&(switch (T) {
u8, i8 => .{mov_reg_imm8 | @intFromEnum(GPRegister.a)},
u16, i16 => prefix_16_bit_operand ++ mov_a_imm,
u32, i32 => mov_a_imm,
u64, i64 => prefix_rex_w ++ mov_a_imm,
else => @compileError("Unsupported"),
} ++ intToArrayOfBytes(integer);
} ++ intToArrayOfBytes(integer)));
}
test "ret void" {
var image = try Image.create();
image.appendCode(&ret);
defer image.destroy();
image.appendCodeByte(ret);
const function_pointer = image.getEntryPoint(fn () callconv(.C) void);
function_pointer();
@ -132,24 +143,6 @@ test "ret void" {
const integer_types_to_test = [_]type{ u8, u16, u32, u64, i8, i16, i32, i64 };
fn testRetInteger(comptime T: type) !void {
comptime {
assert(@typeInfo(T) == .Int);
assert((T == u8 or T == u16 or T == u32 or T == u64) or (T == i8 or T == i16 or T == i32 or T == i64));
}
var image = try Image.create();
const signedness = @typeInfo(T).Int.signedness;
const expected_number = getMaxInteger(T);
image.appendCode(&movAImm(signedness, @bitSizeOf(T), expected_number));
image.appendCode(&ret);
const function_pointer = image.getEntryPoint(fn () callconv(.C) T);
const result = function_pointer();
try expect(result == expected_number);
}
fn getMaxInteger(comptime T: type) T {
comptime {
assert(@typeInfo(T) == .Int);
@ -163,32 +156,69 @@ fn getMaxInteger(comptime T: type) T {
test "ret integer" {
inline for (integer_types_to_test) |Int| {
try testRetInteger(Int);
var image = try Image.create();
defer image.destroy();
const expected_number = getMaxInteger(Int);
movAImm(&image, expected_number);
image.appendCodeByte(ret);
const function_pointer = image.getEntryPoint(fn () callconv(.C) Int);
const result = function_pointer();
try expect(result == expected_number);
}
}
const mov_rm_r = 0x89;
const LastByte = packed struct(u8) {
dst: BasicGPRegister,
src: BasicGPRegister,
always_on: u2 = 0b11,
};
fn movRmR(image: *Image, comptime T: type, dst: BasicGPRegister, src: BasicGPRegister) void {
dstRmSrcR(image, T, .mov, dst, src);
}
fn dstRmSrcR(image: *Image, comptime T: type, opcode: OpcodeRmR, dst: BasicGPRegister, src: BasicGPRegister) void {
const last_byte: u8 = @bitCast(LastByte{
.dst = dst,
.src = src,
});
const opcode_byte = @intFromEnum(opcode);
const bytes = switch (T) {
u8, i8 => blk: {
const base = [_]u8{ opcode_byte - 1, last_byte };
if (@intFromEnum(dst) >= @intFromEnum(BasicGPRegister.sp) or @intFromEnum(src) >= @intFromEnum(BasicGPRegister.sp)) {
image.appendCodeByte(0x40);
}
break :blk base;
},
u16, i16 => prefix_16_bit_operand ++ .{ opcode_byte, last_byte },
u32, i32 => .{ opcode_byte, last_byte },
u64, i64 => prefix_rex_w ++ .{ opcode_byte, last_byte },
else => @compileError("Not supported"),
};
image.appendCode(&bytes);
}
test "ret integer argument" {
inline for (integer_types_to_test) |Int| {
var image = try Image.create();
defer image.destroy();
const number = getMaxInteger(Int);
const mov_a_di = switch (Int) {
u8, i8 => .{ 0x40, 0x88, 0xf8 },
u16, i16 => prefix_16_bit_operand ++ .{ mov_rm_r, 0xf8 },
u32, i32 => .{ mov_rm_r, 0xf8 },
u64, i64 => prefix_rex_w ++ .{ mov_rm_r, 0xf8 },
else => @compileError("Not supported"),
};
image.appendCode(&mov_a_di);
image.appendCode(&ret);
movRmR(&image, Int, .a, .di);
image.appendCodeByte(ret);
const functionPointer = image.getEntryPoint(fn (Int) callconv(.C) Int);
const result = functionPointer(number);
try expectEqual(number, result);
}
}
var r = std.rand.Pcg.init(0xffffffffffffffff);
fn getRandomNumberRange(comptime T: type, min: T, max: T) T {
@ -199,35 +229,113 @@ fn getRandomNumberRange(comptime T: type, min: T, max: T) T {
};
}
const sub_rm_r = 0x29;
fn subRmR(image: *Image, comptime T: type, dst: BasicGPRegister, src: BasicGPRegister) void {
dstRmSrcR(image, T, .sub, dst, src);
}
test "ret sub arguments" {
inline for (integer_types_to_test) |Int| {
var image = try Image.create();
defer image.destroy();
const a = getRandomNumberRange(Int, std.math.minInt(Int) / 2, std.math.maxInt(Int) / 2);
const b = getRandomNumberRange(Int, std.math.minInt(Int) / 2, a);
const mov_a_di = switch (Int) {
u8, i8 => .{ 0x40, 0x88, 0xf8 },
u16, i16 => prefix_16_bit_operand ++ .{ mov_rm_r, 0xf8 },
u32, i32 => .{ mov_rm_r, 0xf8 },
u64, i64 => prefix_rex_w ++ .{ mov_rm_r, 0xf8 },
else => @compileError("Not supported"),
};
image.appendCode(&mov_a_di);
const sub_a_si = switch (Int) {
u8, i8 => .{ 0x40, 0x28, 0xf0 },
u16, i16 => prefix_16_bit_operand ++ .{ sub_rm_r, 0xf0 },
u32, i32 => .{ sub_rm_r, 0xf0 },
u64, i64 => prefix_rex_w ++ .{ sub_rm_r, 0xf0 },
else => @compileError("Not supported"),
};
image.appendCode(&sub_a_si);
image.appendCode(&ret);
movRmR(&image, Int, .a, .di);
subRmR(&image, Int, .a, .si);
image.appendCodeByte(ret);
const functionPointer = image.getEntryPoint(fn (Int, Int) callconv(.C) Int);
const result = functionPointer(a, b);
try expectEqual(a - b, result);
}
}
const OpcodeRmR = enum(u8) {
add = 0x01,
@"or" = 0x09,
@"and" = 0x21,
sub = 0x29,
xor = 0x31,
@"test" = 0x85,
mov = 0x89,
};
test "test binary operations" {
inline for (integer_types_to_test) |T| {
const test_cases = [_]TestIntegerBinaryOperation(T){
.{
.opcode = .add,
.callback = struct {
fn callback(a: T, b: T) T {
return @addWithOverflow(a, b)[0];
}
}.callback,
},
.{
.opcode = .sub,
.callback = struct {
fn callback(a: T, b: T) T {
return @subWithOverflow(a, b)[0];
}
}.callback,
},
.{
.opcode = .@"or",
.callback = struct {
fn callback(a: T, b: T) T {
return a | b;
}
}.callback,
},
.{
.opcode = .@"and",
.callback = struct {
fn callback(a: T, b: T) T {
return a & b;
}
}.callback,
},
.{
.opcode = .xor,
.callback = struct {
fn callback(a: T, b: T) T {
return a ^ b;
}
}.callback,
},
};
for (test_cases) |test_case| {
try test_case.runTest();
}
}
}
fn TestIntegerBinaryOperation(comptime T: type) type {
const should_log = false;
return struct {
callback: *const fn (a: T, b: T) T,
opcode: OpcodeRmR,
pub fn runTest(test_case: @This()) !void {
for (0..10) |_| {
var image = try Image.create();
defer image.destroy();
errdefer image.destroy();
const a = getRandomNumberRange(T, std.math.minInt(T) / 2, std.math.maxInt(T) / 2);
const b = getRandomNumberRange(T, std.math.minInt(T) / 2, a);
movRmR(&image, T, .a, .di);
dstRmSrcR(&image, T, test_case.opcode, .a, .si);
image.appendCodeByte(ret);
const functionPointer = image.getEntryPoint(fn (T, T) callconv(.C) T);
const expected = test_case.callback(a, b);
const result = functionPointer(a, b);
if (should_log) {
log.err("{s} {}, {} ({})", .{ @tagName(test_case.opcode), a, b, T });
}
try expectEqual(expected, result);
}
}
};
}