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Better testing and bugfix in hashUint* functions

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This commit is contained in:
andersfr 2019-07-06 22:41:38 +02:00
parent dfbe65e8cd
commit 0619b525b9
1 changed files with 37 additions and 14 deletions
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51
std/hash/murmur.zig
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@ -1,5 +1,6 @@
const std = @import("std");
const builtin = @import("builtin");
const testing = std.testing;
const default_seed: u32 = 0xc70f6907;
@ -68,10 +69,10 @@ pub const Murmur2_32 = struct {
pub fn hashUint64WithSeed(v: u64, seed: u32) u32 {
const m: u32 = 0x5bd1e995;
const len: u32 = 4;
const len: u32 = 8;
var h1: u32 = seed ^ len;
var k1: u32 = undefined;
k1 = @intCast(u32, v) *% m;
k1 = @intCast(u32, v & 0xffffffff) *% m;
k1 ^= k1 >> 24;
k1 *%= m;
h1 *%= m;
@ -133,10 +134,7 @@ pub const Murmur2_64 = struct {
const m: u64 = 0xc6a4a7935bd1e995;
const len: u64 = 4;
var h1: u64 = seed ^ (len *% m);
var k1: u64 = undefined;
k1 = v *% m;
k1 ^= k1 >> 47;
k1 *%= m;
var k1: u64 = v;
h1 ^= k1;
h1 *%= m;
h1 ^= h1 >> 47;
@ -154,12 +152,7 @@ pub const Murmur2_64 = struct {
const len: u64 = 8;
var h1: u64 = seed ^ (len *% m);
var k1: u64 = undefined;
k1 = @intCast(u32, v) *% m;
k1 ^= k1 >> 47;
k1 *%= m;
h1 ^= k1;
h1 *%= m;
k1 = @intCast(u32, v >> 32) *% m;
k1 = v *% m;
k1 ^= k1 >> 47;
k1 *%= m;
h1 ^= k1;
@ -262,7 +255,7 @@ pub const Murmur3_32 = struct {
const len: u32 = 8;
var h1: u32 = seed;
var k1: u32 = undefined;
k1 = @intCast(u32, v) *% c1;
k1 = @intCast(u32, v & 0xffffffff) *% c1;
k1 = rotl32(k1, 15);
k1 *%= c2;
h1 ^= k1;
@ -310,13 +303,43 @@ fn SMHasherTest(comptime hash_fn: var, comptime hashbits: u32) u32 {
}
test "murmur2_32" {
std.testing.expectEqual(SMHasherTest(Murmur2_32.hashWithSeed, 32), 0x27864C1E);
testing.expectEqual(SMHasherTest(Murmur2_32.hashWithSeed, 32), 0x27864C1E);
var v0: u32 = 0x12345678;
var v1: u64 = 0x1234567812345678;
var v0le: u32 = v0;
var v1le: u64 = v1;
if (builtin.endian == builtin.Endian.Big) {
v0le = @byteSwap(u32, v0le);
v1le = @byteSwap(u64, v1le);
}
testing.expectEqual(Murmur2_32.hash(@ptrCast([*]u8, &v0le)[0..4]), Murmur2_32.hashUint32(v0));
testing.expectEqual(Murmur2_32.hash(@ptrCast([*]u8, &v1le)[0..8]), Murmur2_32.hashUint64(v1));
}
test "murmur2_64" {
std.testing.expectEqual(SMHasherTest(Murmur2_64.hashWithSeed, 64), 0x1F0D3804);
var v0: u32 = 0x12345678;
var v1: u64 = 0x1234567812345678;
var v0le: u32 = v0;
var v1le: u64 = v1;
if (builtin.endian == builtin.Endian.Big) {
v0le = @byteSwap(u32, v0le);
v1le = @byteSwap(u64, v1le);
}
testing.expectEqual(Murmur2_64.hash(@ptrCast([*]u8, &v0le)[0..4]), Murmur2_64.hashUint32(v0));
testing.expectEqual(Murmur2_64.hash(@ptrCast([*]u8, &v1le)[0..8]), Murmur2_64.hashUint64(v1));
}
test "murmur3_32" {
std.testing.expectEqual(SMHasherTest(Murmur3_32.hashWithSeed, 32), 0xB0F57EE3);
var v0: u32 = 0x12345678;
var v1: u64 = 0x1234567812345678;
var v0le: u32 = v0;
var v1le: u64 = v1;
if (builtin.endian == builtin.Endian.Big) {
v0le = @byteSwap(u32, v0le);
v1le = @byteSwap(u64, v1le);
}
testing.expectEqual(Murmur3_32.hash(@ptrCast([*]u8, &v0le)[0..4]), Murmur3_32.hashUint32(v0));
testing.expectEqual(Murmur3_32.hash(@ptrCast([*]u8, &v1le)[0..8]), Murmur3_32.hashUint64(v1));
}