zig/lib/compiler_rt/popcountdi2_test.zig
mlugg f26dda2117 all: migrate code to new cast builtin syntax
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:

* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
2023-06-24 16:56:39 -07:00

36 lines
1.0 KiB
Zig

const std = @import("std");
const popcount = @import("popcount.zig");
const testing = std.testing;
fn popcountdi2Naive(a: i64) i32 {
var x = a;
var r: i32 = 0;
while (x != 0) : (x = @as(i64, @bitCast(@as(u64, @bitCast(x)) >> 1))) {
r += @as(i32, @intCast(x & 1));
}
return r;
}
fn test__popcountdi2(a: i64) !void {
const x = popcount.__popcountdi2(a);
const expected = popcountdi2Naive(a);
try testing.expectEqual(expected, x);
}
test "popcountdi2" {
try test__popcountdi2(0);
try test__popcountdi2(1);
try test__popcountdi2(2);
try test__popcountdi2(@as(i64, @bitCast(@as(u64, 0xffffffff_fffffffd))));
try test__popcountdi2(@as(i64, @bitCast(@as(u64, 0xffffffff_fffffffe))));
try test__popcountdi2(@as(i64, @bitCast(@as(u64, 0xffffffff_ffffffff))));
const RndGen = std.rand.DefaultPrng;
var rnd = RndGen.init(42);
var i: u32 = 0;
while (i < 10_000) : (i += 1) {
var rand_num = rnd.random().int(i64);
try test__popcountdi2(rand_num);
}
}