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zig/std/math/big/int.zig

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const std = @import("../../index.zig");
const builtin = @import("builtin");
const debug = std.debug;
const math = std.math;
const mem = std.mem;
const Allocator = mem.Allocator;
const ArrayList = std.ArrayList;
const TypeId = builtin.TypeId;
pub const Limb = usize;
pub const DoubleLimb = @IntType(false, 2 * Limb.bit_count);
pub const Log2Limb = math.Log2Int(Limb);
comptime {
debug.assert(math.floorPowerOfTwo(usize, Limb.bit_count) == Limb.bit_count);
debug.assert(Limb.bit_count <= 64); // u128 set is unsupported
debug.assert(Limb.is_signed == false);
}
pub const Int = struct {
allocator: *Allocator,
positive: bool,
// - little-endian ordered
// - len >= 1 always
// - zero value -> len == 1 with limbs[0] == 0
limbs: []Limb,
len: usize,
const default_capacity = 4;
pub fn init(allocator: *Allocator) !Int {
return try Int.initCapacity(allocator, default_capacity);
}
pub fn initSet(allocator: *Allocator, value: var) !Int {
var s = try Int.init(allocator);
try s.set(value);
return s;
}
pub fn initCapacity(allocator: *Allocator, capacity: usize) !Int {
return Int{
.allocator = allocator,
.positive = true,
.limbs = block: {
var limbs = try allocator.alloc(Limb, math.max(default_capacity, capacity));
limbs[0] = 0;
break :block limbs;
},
.len = 1,
};
}
pub fn ensureCapacity(self: *Int, capacity: usize) !void {
if (capacity <= self.limbs.len) {
return;
}
self.limbs = try self.allocator.realloc(Limb, self.limbs, capacity);
}
pub fn deinit(self: Int) void {
self.allocator.free(self.limbs);
}
pub fn clone(other: Int) !Int {
return Int{
.allocator = other.allocator,
.positive = other.positive,
.limbs = block: {
var limbs = try other.allocator.alloc(Limb, other.len);
mem.copy(Limb, limbs[0..], other.limbs[0..other.len]);
break :block limbs;
},
.len = other.len,
};
}
pub fn copy(self: *Int, other: Int) !void {
if (self == &other) {
return;
}
self.positive = other.positive;
try self.ensureCapacity(other.len);
mem.copy(Limb, self.limbs[0..], other.limbs[0..other.len]);
self.len = other.len;
}
pub fn swap(self: *Int, other: *Int) void {
mem.swap(Int, self, other);
}
pub fn dump(self: Int) void {
for (self.limbs) |limb| {
debug.warn("{x} ", limb);
}
debug.warn("\n");
}
pub fn negate(r: *Int) void {
r.positive = !r.positive;
}
pub fn abs(r: *Int) void {
r.positive = true;
}
pub fn isOdd(r: Int) bool {
return r.limbs[0] & 1 != 0;
}
pub fn isEven(r: Int) bool {
return !r.isOdd();
}
fn bitcount(self: Int) usize {
const u_bit_count = (self.len - 1) * Limb.bit_count + (Limb.bit_count - @clz(self.limbs[self.len - 1]));
return usize(@boolToInt(!self.positive)) + u_bit_count;
}
pub fn sizeInBase(self: Int, base: usize) usize {
return (self.bitcount() / math.log2(base)) + 1;
}
pub fn set(self: *Int, value: var) Allocator.Error!void {
const T = @typeOf(value);
switch (@typeInfo(T)) {
TypeId.Int => |info| {
const UT = if (T.is_signed) @IntType(false, T.bit_count - 1) else T;
try self.ensureCapacity(@sizeOf(UT) / @sizeOf(Limb));
self.positive = value >= 0;
self.len = 0;
var w_value: UT = if (value < 0) @intCast(UT, -value) else @intCast(UT, value);
if (info.bits <= Limb.bit_count) {
self.limbs[0] = Limb(w_value);
self.len = 1;
} else {
var i: usize = 0;
while (w_value != 0) : (i += 1) {
self.limbs[i] = @truncate(Limb, w_value);
self.len += 1;
// TODO: shift == 64 at compile-time fails. Fails on u128 limbs.
w_value >>= Limb.bit_count / 2;
w_value >>= Limb.bit_count / 2;
}
}
},
TypeId.ComptimeInt => {
comptime var w_value = if (value < 0) -value else value;
const req_limbs = @divFloor(math.log2(w_value), Limb.bit_count) + 1;
try self.ensureCapacity(req_limbs);
self.positive = value >= 0;
self.len = req_limbs;
if (w_value <= @maxValue(Limb)) {
self.limbs[0] = w_value;
} else {
const mask = (1 << Limb.bit_count) - 1;
comptime var i = 0;
inline while (w_value != 0) : (i += 1) {
self.limbs[i] = w_value & mask;
w_value >>= Limb.bit_count / 2;
w_value >>= Limb.bit_count / 2;
}
}
},
else => {
@compileError("cannot set Int using type " ++ @typeName(T));
},
}
}
pub const ConvertError = error{
NegativeIntoUnsigned,
TargetTooSmall,
};
pub fn to(self: Int, comptime T: type) ConvertError!T {
switch (@typeId(T)) {
TypeId.Int => {
const UT = if (T.is_signed) @IntType(false, T.bit_count - 1) else T;
if (self.bitcount() > 8 * @sizeOf(UT)) {
return error.TargetTooSmall;
}
var r: UT = 0;
if (@sizeOf(UT) <= @sizeOf(Limb)) {
r = @intCast(UT, self.limbs[0]);
} else {
for (self.limbs[0..self.len]) |_, ri| {
const limb = self.limbs[self.len - ri - 1];
r <<= Limb.bit_count;
r |= limb;
}
}
if (!T.is_signed) {
return if (self.positive) r else error.NegativeIntoUnsigned;
} else {
return if (self.positive) @intCast(T, r) else -@intCast(T, r);
}
},
else => {
@compileError("cannot convert Int to type " ++ @typeName(T));
},
}
}
fn charToDigit(ch: u8, base: u8) !u8 {
const d = switch (ch) {
'0'...'9' => ch - '0',
'a'...'f' => (ch - 'a') + 0xa,
else => return error.InvalidCharForDigit,
};
return if (d < base) d else return error.DigitTooLargeForBase;
}
fn digitToChar(d: u8, base: u8) !u8 {
if (d >= base) {
return error.DigitTooLargeForBase;
}
return switch (d) {
0...9 => '0' + d,
0xa...0xf => ('a' - 0xa) + d,
else => unreachable,
};
}
pub fn setString(self: *Int, base: u8, value: []const u8) !void {
if (base < 2 or base > 16) {
return error.InvalidBase;
}
var i: usize = 0;
var positive = true;
if (value.len > 0 and value[0] == '-') {
positive = false;
i += 1;
}
// TODO values less than limb size should guarantee non allocating
var base_buffer: [512]u8 = undefined;
const base_al = &std.heap.FixedBufferAllocator.init(base_buffer[0..]).allocator;
const base_ap = try Int.initSet(base_al, base);
var d_buffer: [512]u8 = undefined;
var d_fba = std.heap.FixedBufferAllocator.init(d_buffer[0..]);
const d_al = &d_fba.allocator;
try self.set(0);
for (value[i..]) |ch| {
const d = try charToDigit(ch, base);
d_fba.end_index = 0;
const d_ap = try Int.initSet(d_al, d);
try self.mul(self.*, base_ap);
try self.add(self.*, d_ap);
}
self.positive = positive;
}
pub fn toString(self: Int, allocator: *Allocator, base: u8) ![]const u8 {
if (base < 2 or base > 16) {
return error.InvalidBase;
}
var digits = ArrayList(u8).init(allocator);
try digits.ensureCapacity(self.sizeInBase(base) + 1);
defer digits.deinit();
if (self.eqZero()) {
try digits.append('0');
return digits.toOwnedSlice();
}
// Power of two: can do a single pass and use masks to extract digits.
if (base & (base - 1) == 0) {
const base_shift = math.log2_int(Limb, base);
for (self.limbs[0..self.len]) |limb| {
var shift: usize = 0;
while (shift < Limb.bit_count) : (shift += base_shift) {
const r = @intCast(u8, (limb >> @intCast(Log2Limb, shift)) & Limb(base - 1));
const ch = try digitToChar(r, base);
try digits.append(ch);
}
}
while (true) {
// always will have a non-zero digit somewhere
const c = digits.pop();
if (c != '0') {
digits.append(c) catch unreachable;
break;
}
}
} // Non power-of-two: batch divisions per word size.
else {
const digits_per_limb = math.log(Limb, base, @maxValue(Limb));
var limb_base: Limb = 1;
var j: usize = 0;
while (j < digits_per_limb) : (j += 1) {
limb_base *= base;
}
var q = try self.clone();
q.positive = true;
var r = try Int.init(allocator);
var b = try Int.initSet(allocator, limb_base);
while (q.len >= 2) {
try Int.divTrunc(&q, &r, q, b);
var r_word = r.limbs[0];
var i: usize = 0;
while (i < digits_per_limb) : (i += 1) {
const ch = try digitToChar(@intCast(u8, r_word % base), base);
r_word /= base;
try digits.append(ch);
}
}
{
debug.assert(q.len == 1);
var r_word = q.limbs[0];
while (r_word != 0) {
const ch = try digitToChar(@intCast(u8, r_word % base), base);
r_word /= base;
try digits.append(ch);
}
}
}
if (!self.positive) {
try digits.append('-');
}
var s = digits.toOwnedSlice();
mem.reverse(u8, s);
return s;
}
// returns -1, 0, 1 if |a| < |b|, |a| == |b| or |a| > |b| respectively.
pub fn cmpAbs(a: Int, b: Int) i8 {
if (a.len < b.len) {
return -1;
}
if (a.len > b.len) {
return 1;
}
var i: usize = a.len - 1;
while (i != 0) : (i -= 1) {
if (a.limbs[i] != b.limbs[i]) {
break;
}
}
if (a.limbs[i] < b.limbs[i]) {
return -1;
} else if (a.limbs[i] > b.limbs[i]) {
return 1;
} else {
return 0;
}
}
// returns -1, 0, 1 if a < b, a == b or a > b respectively.
pub fn cmp(a: Int, b: Int) i8 {
if (a.positive != b.positive) {
return if (a.positive) i8(1) else -1;
} else {
const r = cmpAbs(a, b);
return if (a.positive) r else -r;
}
}
// if a == 0
pub fn eqZero(a: Int) bool {
return a.len == 1 and a.limbs[0] == 0;
}
// if |a| == |b|
pub fn eqAbs(a: Int, b: Int) bool {
return cmpAbs(a, b) == 0;
}
// if a == b
pub fn eq(a: Int, b: Int) bool {
return cmp(a, b) == 0;
}
// Normalize for a possible single carry digit.
//
// [1, 2, 3, 4, 0] -> [1, 2, 3, 4]
// [1, 2, 3, 4, 5] -> [1, 2, 3, 4, 5]
// [0] -> [0]
fn norm1(r: *Int, length: usize) void {
debug.assert(length > 0);
debug.assert(length <= r.limbs.len);
if (r.limbs[length - 1] == 0) {
r.len = if (length > 1) length - 1 else 1;
} else {
r.len = length;
}
}
// Normalize a possible sequence of leading zeros.
//
// [1, 2, 3, 4, 0] -> [1, 2, 3, 4]
// [1, 2, 0, 0, 0] -> [1, 2]
// [0, 0, 0, 0, 0] -> [0]
fn normN(r: *Int, length: usize) void {
debug.assert(length > 0);
debug.assert(length <= r.limbs.len);
var j = length;
while (j > 0) : (j -= 1) {
if (r.limbs[j - 1] != 0) {
break;
}
}
// Handle zero
r.len = if (j != 0) j else 1;
}
// r = a + b
pub fn add(r: *Int, a: Int, b: Int) Allocator.Error!void {
if (a.eqZero()) {
try r.copy(b);
return;
} else if (b.eqZero()) {
try r.copy(a);
return;
}
if (a.positive != b.positive) {
if (a.positive) {
// (a) + (-b) => a - b
const bp = Int{
.allocator = undefined,
.positive = true,
.limbs = b.limbs,
.len = b.len,
};
try r.sub(a, bp);
} else {
// (-a) + (b) => b - a
const ap = Int{
.allocator = undefined,
.positive = true,
.limbs = a.limbs,
.len = a.len,
};
try r.sub(b, ap);
}
} else {
if (a.len >= b.len) {
try r.ensureCapacity(a.len + 1);
lladd(r.limbs[0..], a.limbs[0..a.len], b.limbs[0..b.len]);
r.norm1(a.len + 1);
} else {
try r.ensureCapacity(b.len + 1);
lladd(r.limbs[0..], b.limbs[0..b.len], a.limbs[0..a.len]);
r.norm1(b.len + 1);
}
r.positive = a.positive;
}
}
// Knuth 4.3.1, Algorithm A.
fn lladd(r: []Limb, a: []const Limb, b: []const Limb) void {
@setRuntimeSafety(false);
debug.assert(a.len != 0 and b.len != 0);
debug.assert(a.len >= b.len);
debug.assert(r.len >= a.len + 1);
var i: usize = 0;
var carry: Limb = 0;
while (i < b.len) : (i += 1) {
var c: Limb = 0;
c += @boolToInt(@addWithOverflow(Limb, a[i], b[i], &r[i]));
c += @boolToInt(@addWithOverflow(Limb, r[i], carry, &r[i]));
carry = c;
}
while (i < a.len) : (i += 1) {
carry = @boolToInt(@addWithOverflow(Limb, a[i], carry, &r[i]));
}
r[i] = carry;
}
// r = a - b
pub fn sub(r: *Int, a: Int, b: Int) !void {
if (a.positive != b.positive) {
if (a.positive) {
// (a) - (-b) => a + b
const bp = Int{
.allocator = undefined,
.positive = true,
.limbs = b.limbs,
.len = b.len,
};
try r.add(a, bp);
} else {
// (-a) - (b) => -(a + b)
const ap = Int{
.allocator = undefined,
.positive = true,
.limbs = a.limbs,
.len = a.len,
};
try r.add(ap, b);
r.positive = false;
}
} else {
if (a.positive) {
// (a) - (b) => a - b
if (a.cmp(b) >= 0) {
try r.ensureCapacity(a.len + 1);
llsub(r.limbs[0..], a.limbs[0..a.len], b.limbs[0..b.len]);
r.normN(a.len);
r.positive = true;
} else {
try r.ensureCapacity(b.len + 1);
llsub(r.limbs[0..], b.limbs[0..b.len], a.limbs[0..a.len]);
r.normN(b.len);
r.positive = false;
}
} else {
// (-a) - (-b) => -(a - b)
if (a.cmp(b) < 0) {
try r.ensureCapacity(a.len + 1);
llsub(r.limbs[0..], a.limbs[0..a.len], b.limbs[0..b.len]);
r.normN(a.len);
r.positive = false;
} else {
try r.ensureCapacity(b.len + 1);
llsub(r.limbs[0..], b.limbs[0..b.len], a.limbs[0..a.len]);
r.normN(b.len);
r.positive = true;
}
}
}
}
// Knuth 4.3.1, Algorithm S.
fn llsub(r: []Limb, a: []const Limb, b: []const Limb) void {
@setRuntimeSafety(false);
debug.assert(a.len != 0 and b.len != 0);
debug.assert(a.len > b.len or (a.len == b.len and a[a.len - 1] >= b[b.len - 1]));
debug.assert(r.len >= a.len);
var i: usize = 0;
var borrow: Limb = 0;
while (i < b.len) : (i += 1) {
var c: Limb = 0;
c += @boolToInt(@subWithOverflow(Limb, a[i], b[i], &r[i]));
c += @boolToInt(@subWithOverflow(Limb, r[i], borrow, &r[i]));
borrow = c;
}
while (i < a.len) : (i += 1) {
borrow = @boolToInt(@subWithOverflow(Limb, a[i], borrow, &r[i]));
}
debug.assert(borrow == 0);
}
// rma = a * b
//
// For greatest efficiency, ensure rma does not alias a or b.
pub fn mul(rma: *Int, a: Int, b: Int) !void {
var r = rma;
var aliased = rma.limbs.ptr == a.limbs.ptr or rma.limbs.ptr == b.limbs.ptr;
var sr: Int = undefined;
if (aliased) {
sr = try Int.initCapacity(rma.allocator, a.len + b.len);
r = &sr;
aliased = true;
}
defer if (aliased) {
rma.swap(r);
r.deinit();
};
try r.ensureCapacity(a.len + b.len);
if (a.len >= b.len) {
llmul(r.limbs, a.limbs[0..a.len], b.limbs[0..b.len]);
} else {
llmul(r.limbs, b.limbs[0..b.len], a.limbs[0..a.len]);
}
r.positive = a.positive == b.positive;
r.normN(a.len + b.len);
}
// a + b * c + *carry, sets carry to the overflow bits
pub fn addMulLimbWithCarry(a: Limb, b: Limb, c: Limb, carry: *Limb) Limb {
var r1: Limb = undefined;
// r1 = a + *carry
const c1: Limb = @boolToInt(@addWithOverflow(Limb, a, carry.*, &r1));
// r2 = b * c
//
// We still use a DoubleLimb here since the @mulWithOverflow builtin does not
// return the carry and lower bits separately so we would need to perform this
// anyway to get the carry bits. The branch on the overflow case costs more than
// just computing them unconditionally and splitting.
//
// This could be a single x86 mul instruction, which stores the carry/lower in rdx:rax.
const bc = DoubleLimb(b) * DoubleLimb(c);
const r2 = @truncate(Limb, bc);
const c2 = @truncate(Limb, bc >> Limb.bit_count);
// r1 = r1 + r2
const c3: Limb = @boolToInt(@addWithOverflow(Limb, r1, r2, &r1));
// This never overflows, c1, c3 are either 0 or 1 and if both are 1 then
// c2 is at least <= @maxValue(Limb) - 2.
carry.* = c1 + c2 + c3;
return r1;
}
// Knuth 4.3.1, Algorithm M.
//
// r MUST NOT alias any of a or b.
fn llmul(r: []Limb, a: []const Limb, b: []const Limb) void {
@setRuntimeSafety(false);
debug.assert(a.len >= b.len);
debug.assert(r.len >= a.len + b.len);
mem.set(Limb, r[0 .. a.len + b.len], 0);
var i: usize = 0;
while (i < a.len) : (i += 1) {
var carry: Limb = 0;
var j: usize = 0;
while (j < b.len) : (j += 1) {
r[i + j] = @inlineCall(addMulLimbWithCarry, r[i + j], a[i], b[j], &carry);
}
r[i + j] = carry;
}
}
pub fn divFloor(q: *Int, r: *Int, a: Int, b: Int) !void {
try div(q, r, a, b);
// Trunc -> Floor.
if (!q.positive) {
// TODO values less than limb size should guarantee non allocating
var one_buffer: [512]u8 = undefined;
const one_al = &std.heap.FixedBufferAllocator.init(one_buffer[0..]).allocator;
const one_ap = try Int.initSet(one_al, 1);
try q.sub(q.*, one_ap);
try r.add(q.*, one_ap);
}
r.positive = b.positive;
}
pub fn divTrunc(q: *Int, r: *Int, a: Int, b: Int) !void {
try div(q, r, a, b);
r.positive = a.positive;
}
// Truncates by default.
fn div(quo: *Int, rem: *Int, a: Int, b: Int) !void {
if (b.eqZero()) {
@panic("division by zero");
}
if (quo == rem) {
@panic("quo and rem cannot be same variable");
}
if (a.cmpAbs(b) < 0) {
// quo may alias a so handle rem first
try rem.copy(a);
rem.positive = a.positive == b.positive;
quo.positive = true;
quo.len = 1;
quo.limbs[0] = 0;
return;
}
if (b.len == 1) {
try quo.ensureCapacity(a.len);
lldiv1(quo.limbs[0..], &rem.limbs[0], a.limbs[0..a.len], b.limbs[0]);
quo.norm1(a.len);
quo.positive = a.positive == b.positive;
rem.len = 1;
rem.positive = true;
} else {
// x and y are modified during division
var x = try a.clone();
defer x.deinit();
var y = try b.clone();
defer y.deinit();
// x may grow one limb during normalization
try quo.ensureCapacity(a.len + y.len);
try divN(quo.allocator, quo, rem, &x, &y);
quo.positive = a.positive == b.positive;
}
}
// Knuth 4.3.1, Exercise 16.
fn lldiv1(quo: []Limb, rem: *Limb, a: []const Limb, b: Limb) void {
@setRuntimeSafety(false);
debug.assert(a.len > 1 or a[0] >= b);
debug.assert(quo.len >= a.len);
rem.* = 0;
for (a) |_, ri| {
const i = a.len - ri - 1;
const pdiv = ((DoubleLimb(rem.*) << Limb.bit_count) | a[i]);
if (pdiv == 0) {
quo[i] = 0;
rem.* = 0;
} else if (pdiv < b) {
quo[i] = 0;
rem.* = @truncate(Limb, pdiv);
} else if (pdiv == b) {
quo[i] = 1;
rem.* = 0;
} else {
quo[i] = @truncate(Limb, @divTrunc(pdiv, b));
rem.* = @truncate(Limb, pdiv - (quo[i] *% b));
}
}
}
// Handbook of Applied Cryptography, 14.20
//
// x = qy + r where 0 <= r < y
fn divN(allocator: *Allocator, q: *Int, r: *Int, x: *Int, y: *Int) !void {
debug.assert(y.len >= 2);
debug.assert(x.len >= y.len);
debug.assert(q.limbs.len >= x.len + y.len - 1);
debug.assert(default_capacity >= 3); // see 3.2
var tmp = try Int.init(allocator);
defer tmp.deinit();
// Normalize so y > Limb.bit_count / 2 (i.e. leading bit is set)
const norm_shift = @clz(y.limbs[y.len - 1]);
try x.shiftLeft(x.*, norm_shift);
try y.shiftLeft(y.*, norm_shift);
const n = x.len - 1;
const t = y.len - 1;
// 1.
q.len = n - t + 1;
mem.set(Limb, q.limbs[0..q.len], 0);
// 2.
try tmp.shiftLeft(y.*, Limb.bit_count * (n - t));
while (x.cmp(tmp) >= 0) {
q.limbs[n - t] += 1;
try x.sub(x.*, tmp);
}
// 3.
var i = n;
while (i > t) : (i -= 1) {
// 3.1
if (x.limbs[i] == y.limbs[t]) {
q.limbs[i - t - 1] = @maxValue(Limb);
} else {
const num = (DoubleLimb(x.limbs[i]) << Limb.bit_count) | DoubleLimb(x.limbs[i - 1]);
const z = @intCast(Limb, num / DoubleLimb(y.limbs[t]));
q.limbs[i - t - 1] = if (z > @maxValue(Limb)) @maxValue(Limb) else Limb(z);
}
// 3.2
tmp.limbs[0] = if (i >= 2) x.limbs[i - 2] else 0;
tmp.limbs[1] = if (i >= 1) x.limbs[i - 1] else 0;
tmp.limbs[2] = x.limbs[i];
tmp.normN(3);
while (true) {
// 2x1 limb multiplication unrolled against single-limb q[i-t-1]
var carry: Limb = 0;
r.limbs[0] = addMulLimbWithCarry(0, if (t >= 1) y.limbs[t - 1] else 0, q.limbs[i - t - 1], &carry);
r.limbs[1] = addMulLimbWithCarry(0, y.limbs[t], q.limbs[i - t - 1], &carry);
r.limbs[2] = carry;
r.normN(3);
if (r.cmpAbs(tmp) <= 0) {
break;
}
q.limbs[i - t - 1] -= 1;
}
// 3.3
try tmp.set(q.limbs[i - t - 1]);
try tmp.mul(tmp, y.*);
try tmp.shiftLeft(tmp, Limb.bit_count * (i - t - 1));
try x.sub(x.*, tmp);
if (!x.positive) {
try tmp.shiftLeft(y.*, Limb.bit_count * (i - t - 1));
try x.add(x.*, tmp);
q.limbs[i - t - 1] -= 1;
}
}
// Denormalize
q.normN(q.len);
try r.shiftRight(x.*, norm_shift);
r.normN(r.len);
}
// r = a << shift, in other words, r = a * 2^shift
pub fn shiftLeft(r: *Int, a: Int, shift: usize) !void {
try r.ensureCapacity(a.len + (shift / Limb.bit_count) + 1);
llshl(r.limbs[0..], a.limbs[0..a.len], shift);
r.norm1(a.len + (shift / Limb.bit_count) + 1);
r.positive = a.positive;
}
fn llshl(r: []Limb, a: []const Limb, shift: usize) void {
@setRuntimeSafety(false);
debug.assert(a.len >= 1);
debug.assert(r.len >= a.len + (shift / Limb.bit_count) + 1);
const limb_shift = shift / Limb.bit_count + 1;
const interior_limb_shift = @intCast(Log2Limb, shift % Limb.bit_count);
var carry: Limb = 0;
var i: usize = 0;
while (i < a.len) : (i += 1) {
const src_i = a.len - i - 1;
const dst_i = src_i + limb_shift;
const src_digit = a[src_i];
r[dst_i] = carry | @inlineCall(math.shr, Limb, src_digit, Limb.bit_count - @intCast(Limb, interior_limb_shift));
carry = (src_digit << interior_limb_shift);
}
r[limb_shift - 1] = carry;
mem.set(Limb, r[0 .. limb_shift - 1], 0);
}
// r = a >> shift
pub fn shiftRight(r: *Int, a: Int, shift: usize) !void {
if (a.len <= shift / Limb.bit_count) {
r.len = 1;
r.limbs[0] = 0;
r.positive = true;
return;
}
try r.ensureCapacity(a.len - (shift / Limb.bit_count));
const r_len = llshr(r.limbs[0..], a.limbs[0..a.len], shift);
r.len = a.len - (shift / Limb.bit_count);
r.positive = a.positive;
}
fn llshr(r: []Limb, a: []const Limb, shift: usize) void {
@setRuntimeSafety(false);
debug.assert(a.len >= 1);
debug.assert(r.len >= a.len - (shift / Limb.bit_count));
const limb_shift = shift / Limb.bit_count;
const interior_limb_shift = @intCast(Log2Limb, shift % Limb.bit_count);
var carry: Limb = 0;
var i: usize = 0;
while (i < a.len - limb_shift) : (i += 1) {
const src_i = a.len - i - 1;
const dst_i = src_i - limb_shift;
const src_digit = a[src_i];
r[dst_i] = carry | (src_digit >> interior_limb_shift);
carry = @inlineCall(math.shl, Limb, src_digit, Limb.bit_count - @intCast(Limb, interior_limb_shift));
}
}
// r = a | b
pub fn bitOr(r: *Int, a: Int, b: Int) !void {
if (a.len > b.len) {
try r.ensureCapacity(a.len);
llor(r.limbs[0..], a.limbs[0..a.len], b.limbs[0..b.len]);
r.len = a.len;
} else {
try r.ensureCapacity(b.len);
llor(r.limbs[0..], b.limbs[0..b.len], a.limbs[0..a.len]);
r.len = b.len;
}
}
fn llor(r: []Limb, a: []const Limb, b: []const Limb) void {
@setRuntimeSafety(false);
debug.assert(r.len >= a.len);
debug.assert(a.len >= b.len);
var i: usize = 0;
while (i < b.len) : (i += 1) {
r[i] = a[i] | b[i];
}
while (i < a.len) : (i += 1) {
r[i] = a[i];
}
}
// r = a & b
pub fn bitAnd(r: *Int, a: Int, b: Int) !void {
if (a.len > b.len) {
try r.ensureCapacity(b.len);
lland(r.limbs[0..], a.limbs[0..a.len], b.limbs[0..b.len]);
r.normN(b.len);
} else {
try r.ensureCapacity(a.len);
lland(r.limbs[0..], b.limbs[0..b.len], a.limbs[0..a.len]);
r.normN(a.len);
}
}
fn lland(r: []Limb, a: []const Limb, b: []const Limb) void {
@setRuntimeSafety(false);
debug.assert(r.len >= b.len);
debug.assert(a.len >= b.len);
var i: usize = 0;
while (i < b.len) : (i += 1) {
r[i] = a[i] & b[i];
}
}
// r = a ^ b
pub fn bitXor(r: *Int, a: Int, b: Int) !void {
if (a.len > b.len) {
try r.ensureCapacity(a.len);
llxor(r.limbs[0..], a.limbs[0..a.len], b.limbs[0..b.len]);
r.normN(a.len);
} else {
try r.ensureCapacity(b.len);
llxor(r.limbs[0..], b.limbs[0..b.len], a.limbs[0..a.len]);
r.normN(b.len);
}
}
fn llxor(r: []Limb, a: []const Limb, b: []const Limb) void {
@setRuntimeSafety(false);
debug.assert(r.len >= a.len);
debug.assert(a.len >= b.len);
var i: usize = 0;
while (i < b.len) : (i += 1) {
r[i] = a[i] ^ b[i];
}
while (i < a.len) : (i += 1) {
r[i] = a[i];
}
}
};
// NOTE: All the following tests assume the max machine-word will be 64-bit.
//
// They will still run on larger than this and should pass, but the multi-limb code-paths
// may be untested in some cases.
const u256 = @IntType(false, 256);
const al = debug.global_allocator;
test "big.int comptime_int set" {
comptime var s = 0xefffffff00000001eeeeeeefaaaaaaab;
var a = try Int.initSet(al, s);
const s_limb_count = 128 / Limb.bit_count;
comptime var i: usize = 0;
inline while (i < s_limb_count) : (i += 1) {
const result = Limb(s & @maxValue(Limb));
s >>= Limb.bit_count / 2;
s >>= Limb.bit_count / 2;
debug.assert(a.limbs[i] == result);
}
}
test "big.int comptime_int set negative" {
var a = try Int.initSet(al, -10);
debug.assert(a.limbs[0] == 10);
debug.assert(a.positive == false);
}
test "big.int int set unaligned small" {
var a = try Int.initSet(al, u7(45));
debug.assert(a.limbs[0] == 45);
debug.assert(a.positive == true);
}
test "big.int comptime_int to" {
const a = try Int.initSet(al, 0xefffffff00000001eeeeeeefaaaaaaab);
debug.assert((try a.to(u128)) == 0xefffffff00000001eeeeeeefaaaaaaab);
}
test "big.int sub-limb to" {
const a = try Int.initSet(al, 10);
debug.assert((try a.to(u8)) == 10);
}
test "big.int to target too small error" {
const a = try Int.initSet(al, 0xffffffff);
if (a.to(u8)) |_| {
unreachable;
} else |err| {
debug.assert(err == error.TargetTooSmall);
}
}
test "big.int norm1" {
var a = try Int.init(al);
try a.ensureCapacity(8);
a.limbs[0] = 1;
a.limbs[1] = 2;
a.limbs[2] = 3;
a.limbs[3] = 0;
a.norm1(4);
debug.assert(a.len == 3);
a.limbs[0] = 1;
a.limbs[1] = 2;
a.limbs[2] = 3;
a.norm1(3);
debug.assert(a.len == 3);
a.limbs[0] = 0;
a.limbs[1] = 0;
a.norm1(2);
debug.assert(a.len == 1);
a.limbs[0] = 0;
a.norm1(1);
debug.assert(a.len == 1);
}
test "big.int normN" {
var a = try Int.init(al);
try a.ensureCapacity(8);
a.limbs[0] = 1;
a.limbs[1] = 2;
a.limbs[2] = 0;
a.limbs[3] = 0;
a.normN(4);
debug.assert(a.len == 2);
a.limbs[0] = 1;
a.limbs[1] = 2;
a.limbs[2] = 3;
a.normN(3);
debug.assert(a.len == 3);
a.limbs[0] = 0;
a.limbs[1] = 0;
a.limbs[2] = 0;
a.limbs[3] = 0;
a.normN(4);
debug.assert(a.len == 1);
a.limbs[0] = 0;
a.normN(1);
debug.assert(a.len == 1);
}
test "big.int parity" {
var a = try Int.init(al);
try a.set(0);
debug.assert(a.isEven());
debug.assert(!a.isOdd());
try a.set(7);
debug.assert(!a.isEven());
debug.assert(a.isOdd());
}
test "big.int bitcount + sizeInBase" {
var a = try Int.init(al);
try a.set(0b100);
debug.assert(a.bitcount() == 3);
debug.assert(a.sizeInBase(2) >= 3);
debug.assert(a.sizeInBase(10) >= 1);
try a.set(0xffffffff);
debug.assert(a.bitcount() == 32);
debug.assert(a.sizeInBase(2) >= 32);
debug.assert(a.sizeInBase(10) >= 10);
try a.shiftLeft(a, 5000);
debug.assert(a.bitcount() == 5032);
debug.assert(a.sizeInBase(2) >= 5032);
a.positive = false;
debug.assert(a.bitcount() == 5033);
debug.assert(a.sizeInBase(2) >= 5033);
}
test "big.int string set" {
var a = try Int.init(al);
try a.setString(10, "120317241209124781241290847124");
debug.assert((try a.to(u128)) == 120317241209124781241290847124);
}
test "big.int string negative" {
var a = try Int.init(al);
try a.setString(10, "-1023");
debug.assert((try a.to(i32)) == -1023);
}
test "big.int string set bad char error" {
var a = try Int.init(al);
a.setString(10, "x") catch |err| debug.assert(err == error.InvalidCharForDigit);
}
test "big.int string set bad base error" {
var a = try Int.init(al);
a.setString(45, "10") catch |err| debug.assert(err == error.InvalidBase);
}
test "big.int string to" {
const a = try Int.initSet(al, 120317241209124781241290847124);
const as = try a.toString(al, 10);
const es = "120317241209124781241290847124";
debug.assert(mem.eql(u8, as, es));
}
test "big.int string to base base error" {
const a = try Int.initSet(al, 0xffffffff);
if (a.toString(al, 45)) |_| {
unreachable;
} else |err| {
debug.assert(err == error.InvalidBase);
}
}
test "big.int string to base 2" {
const a = try Int.initSet(al, -0b1011);
const as = try a.toString(al, 2);
const es = "-1011";
debug.assert(mem.eql(u8, as, es));
}
test "big.int string to base 16" {
const a = try Int.initSet(al, 0xefffffff00000001eeeeeeefaaaaaaab);
const as = try a.toString(al, 16);
const es = "efffffff00000001eeeeeeefaaaaaaab";
debug.assert(mem.eql(u8, as, es));
}
test "big.int neg string to" {
const a = try Int.initSet(al, -123907434);
const as = try a.toString(al, 10);
const es = "-123907434";
debug.assert(mem.eql(u8, as, es));
}
test "big.int zero string to" {
const a = try Int.initSet(al, 0);
const as = try a.toString(al, 10);
const es = "0";
debug.assert(mem.eql(u8, as, es));
}
test "big.int clone" {
var a = try Int.initSet(al, 1234);
const b = try a.clone();
debug.assert((try a.to(u32)) == 1234);
debug.assert((try b.to(u32)) == 1234);
try a.set(77);
debug.assert((try a.to(u32)) == 77);
debug.assert((try b.to(u32)) == 1234);
}
test "big.int swap" {
var a = try Int.initSet(al, 1234);
var b = try Int.initSet(al, 5678);
debug.assert((try a.to(u32)) == 1234);
debug.assert((try b.to(u32)) == 5678);
a.swap(&b);
debug.assert((try a.to(u32)) == 5678);
debug.assert((try b.to(u32)) == 1234);
}
test "big.int to negative" {
var a = try Int.initSet(al, -10);
debug.assert((try a.to(i32)) == -10);
}
test "big.int compare" {
var a = try Int.initSet(al, -11);
var b = try Int.initSet(al, 10);
debug.assert(a.cmpAbs(b) == 1);
debug.assert(a.cmp(b) == -1);
}
test "big.int compare similar" {
var a = try Int.initSet(al, 0xffffffffeeeeeeeeffffffffeeeeeeee);
var b = try Int.initSet(al, 0xffffffffeeeeeeeeffffffffeeeeeeef);
debug.assert(a.cmpAbs(b) == -1);
debug.assert(b.cmpAbs(a) == 1);
}
test "big.int compare different limb size" {
var a = try Int.initSet(al, @maxValue(Limb) + 1);
var b = try Int.initSet(al, 1);
debug.assert(a.cmpAbs(b) == 1);
debug.assert(b.cmpAbs(a) == -1);
}
test "big.int compare multi-limb" {
var a = try Int.initSet(al, -0x7777777799999999ffffeeeeffffeeeeffffeeeef);
var b = try Int.initSet(al, 0x7777777799999999ffffeeeeffffeeeeffffeeeee);
debug.assert(a.cmpAbs(b) == 1);
debug.assert(a.cmp(b) == -1);
}
test "big.int equality" {
var a = try Int.initSet(al, 0xffffffff1);
var b = try Int.initSet(al, -0xffffffff1);
debug.assert(a.eqAbs(b));
debug.assert(!a.eq(b));
}
test "big.int abs" {
var a = try Int.initSet(al, -5);
a.abs();
debug.assert((try a.to(u32)) == 5);
a.abs();
debug.assert((try a.to(u32)) == 5);
}
test "big.int negate" {
var a = try Int.initSet(al, 5);
a.negate();
debug.assert((try a.to(i32)) == -5);
a.negate();
debug.assert((try a.to(i32)) == 5);
}
test "big.int add single-single" {
var a = try Int.initSet(al, 50);
var b = try Int.initSet(al, 5);
var c = try Int.init(al);
try c.add(a, b);
debug.assert((try c.to(u32)) == 55);
}
test "big.int add multi-single" {
var a = try Int.initSet(al, @maxValue(Limb) + 1);
var b = try Int.initSet(al, 1);
var c = try Int.init(al);
try c.add(a, b);
debug.assert((try c.to(DoubleLimb)) == @maxValue(Limb) + 2);
try c.add(b, a);
debug.assert((try c.to(DoubleLimb)) == @maxValue(Limb) + 2);
}
test "big.int add multi-multi" {
const op1 = 0xefefefef7f7f7f7f;
const op2 = 0xfefefefe9f9f9f9f;
var a = try Int.initSet(al, op1);
var b = try Int.initSet(al, op2);
var c = try Int.init(al);
try c.add(a, b);
debug.assert((try c.to(u128)) == op1 + op2);
}
test "big.int add zero-zero" {
var a = try Int.initSet(al, 0);
var b = try Int.initSet(al, 0);
var c = try Int.init(al);
try c.add(a, b);
debug.assert((try c.to(u32)) == 0);
}
test "big.int add alias multi-limb nonzero-zero" {
const op1 = 0xffffffff777777771;
var a = try Int.initSet(al, op1);
var b = try Int.initSet(al, 0);
try a.add(a, b);
debug.assert((try a.to(u128)) == op1);
}
test "big.int add sign" {
var a = try Int.init(al);
const one = try Int.initSet(al, 1);
const two = try Int.initSet(al, 2);
const neg_one = try Int.initSet(al, -1);
const neg_two = try Int.initSet(al, -2);
try a.add(one, two);
debug.assert((try a.to(i32)) == 3);
try a.add(neg_one, two);
debug.assert((try a.to(i32)) == 1);
try a.add(one, neg_two);
debug.assert((try a.to(i32)) == -1);
try a.add(neg_one, neg_two);
debug.assert((try a.to(i32)) == -3);
}
test "big.int sub single-single" {
var a = try Int.initSet(al, 50);
var b = try Int.initSet(al, 5);
var c = try Int.init(al);
try c.sub(a, b);
debug.assert((try c.to(u32)) == 45);
}
test "big.int sub multi-single" {
var a = try Int.initSet(al, @maxValue(Limb) + 1);
var b = try Int.initSet(al, 1);
var c = try Int.init(al);
try c.sub(a, b);
debug.assert((try c.to(Limb)) == @maxValue(Limb));
}
test "big.int sub multi-multi" {
const op1 = 0xefefefefefefefefefefefef;
const op2 = 0xabababababababababababab;
var a = try Int.initSet(al, op1);
var b = try Int.initSet(al, op2);
var c = try Int.init(al);
try c.sub(a, b);
debug.assert((try c.to(u128)) == op1 - op2);
}
test "big.int sub equal" {
var a = try Int.initSet(al, 0x11efefefefefefefefefefefef);
var b = try Int.initSet(al, 0x11efefefefefefefefefefefef);
var c = try Int.init(al);
try c.sub(a, b);
debug.assert((try c.to(u32)) == 0);
}
test "big.int sub sign" {
var a = try Int.init(al);
const one = try Int.initSet(al, 1);
const two = try Int.initSet(al, 2);
const neg_one = try Int.initSet(al, -1);
const neg_two = try Int.initSet(al, -2);
try a.sub(one, two);
debug.assert((try a.to(i32)) == -1);
try a.sub(neg_one, two);
debug.assert((try a.to(i32)) == -3);
try a.sub(one, neg_two);
debug.assert((try a.to(i32)) == 3);
try a.sub(neg_one, neg_two);
debug.assert((try a.to(i32)) == 1);
try a.sub(neg_two, neg_one);
debug.assert((try a.to(i32)) == -1);
}
test "big.int mul single-single" {
var a = try Int.initSet(al, 50);
var b = try Int.initSet(al, 5);
var c = try Int.init(al);
try c.mul(a, b);
debug.assert((try c.to(u64)) == 250);
}
test "big.int mul multi-single" {
var a = try Int.initSet(al, @maxValue(Limb));
var b = try Int.initSet(al, 2);
var c = try Int.init(al);
try c.mul(a, b);
debug.assert((try c.to(DoubleLimb)) == 2 * @maxValue(Limb));
}
test "big.int mul multi-multi" {
const op1 = 0x998888efefefefefefefef;
const op2 = 0x333000abababababababab;
var a = try Int.initSet(al, op1);
var b = try Int.initSet(al, op2);
var c = try Int.init(al);
try c.mul(a, b);
debug.assert((try c.to(u256)) == op1 * op2);
}
test "big.int mul alias r with a" {
var a = try Int.initSet(al, @maxValue(Limb));
var b = try Int.initSet(al, 2);
try a.mul(a, b);
debug.assert((try a.to(DoubleLimb)) == 2 * @maxValue(Limb));
}
test "big.int mul alias r with b" {
var a = try Int.initSet(al, @maxValue(Limb));
var b = try Int.initSet(al, 2);
try a.mul(b, a);
debug.assert((try a.to(DoubleLimb)) == 2 * @maxValue(Limb));
}
test "big.int mul alias r with a and b" {
var a = try Int.initSet(al, @maxValue(Limb));
try a.mul(a, a);
debug.assert((try a.to(DoubleLimb)) == @maxValue(Limb) * @maxValue(Limb));
}
test "big.int mul a*0" {
var a = try Int.initSet(al, 0xefefefefefefefef);
var b = try Int.initSet(al, 0);
var c = try Int.init(al);
try c.mul(a, b);
debug.assert((try c.to(u32)) == 0);
}
test "big.int mul 0*0" {
var a = try Int.initSet(al, 0);
var b = try Int.initSet(al, 0);
var c = try Int.init(al);
try c.mul(a, b);
debug.assert((try c.to(u32)) == 0);
}
test "big.int div single-single no rem" {
var a = try Int.initSet(al, 50);
var b = try Int.initSet(al, 5);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u32)) == 10);
debug.assert((try r.to(u32)) == 0);
}
test "big.int div single-single with rem" {
var a = try Int.initSet(al, 49);
var b = try Int.initSet(al, 5);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u32)) == 9);
debug.assert((try r.to(u32)) == 4);
}
test "big.int div multi-single no rem" {
const op1 = 0xffffeeeeddddcccc;
const op2 = 34;
var a = try Int.initSet(al, op1);
var b = try Int.initSet(al, op2);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u64)) == op1 / op2);
debug.assert((try r.to(u64)) == 0);
}
test "big.int div multi-single with rem" {
const op1 = 0xffffeeeeddddcccf;
const op2 = 34;
var a = try Int.initSet(al, op1);
var b = try Int.initSet(al, op2);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u64)) == op1 / op2);
debug.assert((try r.to(u64)) == 3);
}
test "big.int div multi>2-single" {
const op1 = 0xfefefefefefefefefefefefefefefefe;
const op2 = 0xefab8;
var a = try Int.initSet(al, op1);
var b = try Int.initSet(al, op2);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u128)) == op1 / op2);
debug.assert((try r.to(u32)) == 0x3e4e);
}
test "big.int div single-single q < r" {
var a = try Int.initSet(al, 0x0078f432);
var b = try Int.initSet(al, 0x01000000);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u64)) == 0);
debug.assert((try r.to(u64)) == 0x0078f432);
}
test "big.int div single-single q == r" {
var a = try Int.initSet(al, 10);
var b = try Int.initSet(al, 10);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u64)) == 1);
debug.assert((try r.to(u64)) == 0);
}
test "big.int div q=0 alias" {
var a = try Int.initSet(al, 3);
var b = try Int.initSet(al, 10);
try Int.divTrunc(&a, &b, a, b);
debug.assert((try a.to(u64)) == 0);
debug.assert((try b.to(u64)) == 3);
}
test "big.int div multi-multi q < r" {
const op1 = 0x1ffffffff0078f432;
const op2 = 0x1ffffffff01000000;
var a = try Int.initSet(al, op1);
var b = try Int.initSet(al, op2);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u128)) == 0);
debug.assert((try r.to(u128)) == op1);
}
test "big.int div trunc single-single +/+" {
const u: i32 = 5;
const v: i32 = 3;
var a = try Int.initSet(al, u);
var b = try Int.initSet(al, v);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
// n = q * d + r
// 5 = 1 * 3 + 2
const eq = @divTrunc(u, v);
const er = @mod(u, v);
debug.assert((try q.to(i32)) == eq);
debug.assert((try r.to(i32)) == er);
}
test "big.int div trunc single-single -/+" {
const u: i32 = -5;
const v: i32 = 3;
var a = try Int.initSet(al, u);
var b = try Int.initSet(al, v);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
// n = q * d + r
// -5 = 1 * -3 - 2
const eq = -1;
const er = -2;
debug.assert((try q.to(i32)) == eq);
debug.assert((try r.to(i32)) == er);
}
test "big.int div trunc single-single +/-" {
const u: i32 = 5;
const v: i32 = -3;
var a = try Int.initSet(al, u);
var b = try Int.initSet(al, v);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
// n = q * d + r
// 5 = -1 * -3 + 2
const eq = -1;
const er = 2;
debug.assert((try q.to(i32)) == eq);
debug.assert((try r.to(i32)) == er);
}
test "big.int div trunc single-single -/-" {
const u: i32 = -5;
const v: i32 = -3;
var a = try Int.initSet(al, u);
var b = try Int.initSet(al, v);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
// n = q * d + r
// -5 = 1 * -3 - 2
const eq = 1;
const er = -2;
debug.assert((try q.to(i32)) == eq);
debug.assert((try r.to(i32)) == er);
}
test "big.int div floor single-single +/+" {
const u: i32 = 5;
const v: i32 = 3;
var a = try Int.initSet(al, u);
var b = try Int.initSet(al, v);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divFloor(&q, &r, a, b);
// n = q * d + r
// 5 = 1 * 3 + 2
const eq = 1;
const er = 2;
debug.assert((try q.to(i32)) == eq);
debug.assert((try r.to(i32)) == er);
}
test "big.int div floor single-single -/+" {
const u: i32 = -5;
const v: i32 = 3;
var a = try Int.initSet(al, u);
var b = try Int.initSet(al, v);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divFloor(&q, &r, a, b);
// n = q * d + r
// -5 = -2 * 3 + 1
const eq = -2;
const er = 1;
debug.assert((try q.to(i32)) == eq);
debug.assert((try r.to(i32)) == er);
}
test "big.int div floor single-single +/-" {
const u: i32 = 5;
const v: i32 = -3;
var a = try Int.initSet(al, u);
var b = try Int.initSet(al, v);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divFloor(&q, &r, a, b);
// n = q * d + r
// 5 = -2 * -3 - 1
const eq = -2;
const er = -1;
debug.assert((try q.to(i32)) == eq);
debug.assert((try r.to(i32)) == er);
}
test "big.int div floor single-single -/-" {
const u: i32 = -5;
const v: i32 = -3;
var a = try Int.initSet(al, u);
var b = try Int.initSet(al, v);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divFloor(&q, &r, a, b);
// n = q * d + r
// -5 = 2 * -3 + 1
const eq = 1;
const er = -2;
debug.assert((try q.to(i32)) == eq);
debug.assert((try r.to(i32)) == er);
}
test "big.int div multi-multi with rem" {
var a = try Int.initSet(al, 0x8888999911110000ffffeeeeddddccccbbbbaaaa9999);
var b = try Int.initSet(al, 0x99990000111122223333);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u128)) == 0xe38f38e39161aaabd03f0f1b);
debug.assert((try r.to(u128)) == 0x28de0acacd806823638);
}
test "big.int div multi-multi no rem" {
var a = try Int.initSet(al, 0x8888999911110000ffffeeeedb4fec200ee3a4286361);
var b = try Int.initSet(al, 0x99990000111122223333);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u128)) == 0xe38f38e39161aaabd03f0f1b);
debug.assert((try r.to(u128)) == 0);
}
test "big.int div multi-multi (2 branch)" {
var a = try Int.initSet(al, 0x866666665555555588888887777777761111111111111111);
var b = try Int.initSet(al, 0x86666666555555554444444433333333);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u128)) == 0x10000000000000000);
debug.assert((try r.to(u128)) == 0x44444443444444431111111111111111);
}
test "big.int div multi-multi (3.1/3.3 branch)" {
var a = try Int.initSet(al, 0x11111111111111111111111111111111111111111111111111111111111111);
var b = try Int.initSet(al, 0x1111111111111111111111111111111111111111171);
var q = try Int.init(al);
var r = try Int.init(al);
try Int.divTrunc(&q, &r, a, b);
debug.assert((try q.to(u128)) == 0xfffffffffffffffffff);
debug.assert((try r.to(u256)) == 0x1111111111111111111110b12222222222222222282);
}
test "big.int shift-right single" {
var a = try Int.initSet(al, 0xffff0000);
try a.shiftRight(a, 16);
debug.assert((try a.to(u32)) == 0xffff);
}
test "big.int shift-right multi" {
var a = try Int.initSet(al, 0xffff0000eeee1111dddd2222cccc3333);
try a.shiftRight(a, 67);
debug.assert((try a.to(u64)) == 0x1fffe0001dddc222);
}
test "big.int shift-left single" {
var a = try Int.initSet(al, 0xffff);
try a.shiftLeft(a, 16);
debug.assert((try a.to(u64)) == 0xffff0000);
}
test "big.int shift-left multi" {
var a = try Int.initSet(al, 0x1fffe0001dddc222);
try a.shiftLeft(a, 67);
debug.assert((try a.to(u128)) == 0xffff0000eeee11100000000000000000);
}
test "big.int shift-right negative" {
var a = try Int.init(al);
try a.shiftRight(try Int.initSet(al, -20), 2);
debug.assert((try a.to(i32)) == -20 >> 2);
try a.shiftRight(try Int.initSet(al, -5), 10);
debug.assert((try a.to(i32)) == -5 >> 10);
}
test "big.int shift-left negative" {
var a = try Int.init(al);
try a.shiftRight(try Int.initSet(al, -10), 1232);
debug.assert((try a.to(i32)) == -10 >> 1232);
}
test "big.int bitwise and simple" {
var a = try Int.initSet(al, 0xffffffff11111111);
var b = try Int.initSet(al, 0xeeeeeeee22222222);
try a.bitAnd(a, b);
debug.assert((try a.to(u64)) == 0xeeeeeeee00000000);
}
test "big.int bitwise and multi-limb" {
var a = try Int.initSet(al, @maxValue(Limb) + 1);
var b = try Int.initSet(al, @maxValue(Limb));
try a.bitAnd(a, b);
debug.assert((try a.to(u128)) == 0);
}
test "big.int bitwise xor simple" {
var a = try Int.initSet(al, 0xffffffff11111111);
var b = try Int.initSet(al, 0xeeeeeeee22222222);
try a.bitXor(a, b);
debug.assert((try a.to(u64)) == 0x1111111133333333);
}
test "big.int bitwise xor multi-limb" {
var a = try Int.initSet(al, @maxValue(Limb) + 1);
var b = try Int.initSet(al, @maxValue(Limb));
try a.bitXor(a, b);
debug.assert((try a.to(DoubleLimb)) == (@maxValue(Limb) + 1) ^ @maxValue(Limb));
}
test "big.int bitwise or simple" {
var a = try Int.initSet(al, 0xffffffff11111111);
var b = try Int.initSet(al, 0xeeeeeeee22222222);
try a.bitOr(a, b);
debug.assert((try a.to(u64)) == 0xffffffff33333333);
}
test "big.int bitwise or multi-limb" {
var a = try Int.initSet(al, @maxValue(Limb) + 1);
var b = try Int.initSet(al, @maxValue(Limb));
try a.bitOr(a, b);
// TODO: big.int.cpp or is wrong on multi-limb.
debug.assert((try a.to(DoubleLimb)) == (@maxValue(Limb) + 1) + @maxValue(Limb));
}
test "big.int var args" {
var a = try Int.initSet(al, 5);
try a.add(a, try Int.initSet(al, 6));
debug.assert((try a.to(u64)) == 11);
debug.assert(a.cmp(try Int.initSet(al, 11)) == 0);
debug.assert(a.cmp(try Int.initSet(al, 14)) <= 0);
}
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