mirror of
https://github.com/ziglang/zig.git
synced 2025-12-08 15:23:14 +00:00
33 lines
1.1 KiB
Zig
33 lines
1.1 KiB
Zig
// SPDX-License-Identifier: MIT
|
|
// Copyright (c) 2015-2021 Zig Contributors
|
|
// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
|
|
// The MIT license requires this copyright notice to be included in all copies
|
|
// and substantial portions of the software.
|
|
const __popcountdi2 = @import("popcountdi2.zig").__popcountdi2;
|
|
const testing = @import("std").testing;
|
|
|
|
fn naive_popcount(a_param: i64) i32 {
|
|
var a = a_param;
|
|
var r: i32 = 0;
|
|
while (a != 0) : (a = @bitCast(i64, @bitCast(u64, a) >> 1)) {
|
|
r += @intCast(i32, a & 1);
|
|
}
|
|
return r;
|
|
}
|
|
|
|
fn test__popcountdi2(a: i64) !void {
|
|
const x = __popcountdi2(a);
|
|
const expected = naive_popcount(a);
|
|
try testing.expect(expected == x);
|
|
}
|
|
|
|
test "popcountdi2" {
|
|
try test__popcountdi2(0);
|
|
try test__popcountdi2(1);
|
|
try test__popcountdi2(2);
|
|
try test__popcountdi2(@bitCast(i64, @as(u64, 0xFFFFFFFFFFFFFFFD)));
|
|
try test__popcountdi2(@bitCast(i64, @as(u64, 0xFFFFFFFFFFFFFFFE)));
|
|
try test__popcountdi2(@bitCast(i64, @as(u64, 0xFFFFFFFFFFFFFFFF)));
|
|
// TODO some fuzz testing
|
|
}
|