Commit 5c8912d7a4

David <87927264+Rexicon226@users.noreply.github.com>
2023-10-17 20:55:01
XXH3 Implementation for Zig STD (#17530)
XXH3 is the faster alternative to XXH64 which utilizes SIMD when hashing large chunks of memory and similar mixing to WyHash (64x64 -> 128 mul) for smaller inputs. Co-authored-by: Reixcon226 <87927264+Rexicon226@users.noreply.github.com> --------- Co-authored-by: kprotty <kbutcher6200@gmail.com>
1 parent 3b21c15
Changed files (3)
lib/std/hash/benchmark.zig
@@ -24,6 +24,12 @@ const Hash = struct {
 };
 
 const hashes = [_]Hash{
+    Hash{
+        .ty = hash.XxHash3,
+        .name = "xxh3",
+        .init_u64 = 0,
+        .has_anytype_api = @as([]const comptime_int, &[_]comptime_int{ 8, 16, 32, 48, 64, 80, 96, 112, 128 }),
+    },
     Hash{
         .ty = hash.XxHash64,
         .name = "xxhash64",
lib/std/hash/xxhash.zig
@@ -1,4 +1,5 @@
 const std = @import("std");
+const builtin = @import("builtin");
 const mem = std.mem;
 const expectEqual = std.testing.expectEqual;
 
@@ -426,6 +427,361 @@ pub const XxHash32 = struct {
     }
 };
 
+pub const XxHash3 = struct {
+    const Block = @Vector(8, u64);
+    const default_secret: [192]u8 = .{
+        0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, 0xf7, 0x21, 0xad, 0x1c,
+        0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb, 0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f,
+        0xcb, 0x79, 0xe6, 0x4e, 0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21,
+        0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6, 0x81, 0x3a, 0x26, 0x4c,
+        0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb, 0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3,
+        0x71, 0x64, 0x48, 0x97, 0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8,
+        0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7, 0xc7, 0x0b, 0x4f, 0x1d,
+        0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31, 0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64,
+        0xea, 0xc5, 0xac, 0x83, 0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb,
+        0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26, 0x29, 0xd4, 0x68, 0x9e,
+        0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc, 0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce,
+        0x45, 0xcb, 0x3a, 0x8f, 0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e,
+    };
+
+    const prime_mx1 = 0x165667919E3779F9;
+    const prime_mx2 = 0x9FB21C651E98DF25;
+
+    inline fn avalanche(mode: union(enum) { h3, h64, rrmxmx: u64 }, x0: u64) u64 {
+        switch (mode) {
+            .h3 => {
+                const x1 = (x0 ^ (x0 >> 37)) *% prime_mx1;
+                return x1 ^ (x1 >> 32);
+            },
+            .h64 => {
+                const x1 = (x0 ^ (x0 >> 33)) *% XxHash64.prime_2;
+                const x2 = (x1 ^ (x1 >> 29)) *% XxHash64.prime_3;
+                return x2 ^ (x2 >> 32);
+            },
+            .rrmxmx => |len| {
+                const x1 = (x0 ^ rotl(u64, x0, 49) ^ rotl(u64, x0, 24)) *% prime_mx2;
+                const x2 = (x1 ^ ((x1 >> 35) +% len)) *% prime_mx2;
+                return x2 ^ (x2 >> 28);
+            },
+        }
+    }
+
+    inline fn fold(a: u64, b: u64) u64 {
+        const wide: [2]u64 = @bitCast(@as(u128, a) *% b);
+        return wide[0] ^ wide[1];
+    }
+
+    inline fn swap(x: anytype) @TypeOf(x) {
+        return if (builtin.cpu.arch.endian() == .Big) @byteSwap(x) else x;
+    }
+
+    inline fn disableAutoVectorization(x: anytype) void {
+        if (!@inComptime()) asm volatile (""
+            :
+            : [x] "r" (x),
+        );
+    }
+
+    inline fn mix16(seed: u64, input: []const u8, secret: []const u8) u64 {
+        const blk: [4]u64 = @bitCast([_][16]u8{ input[0..16].*, secret[0..16].* });
+        disableAutoVectorization(seed);
+
+        return fold(
+            swap(blk[0]) ^ (swap(blk[2]) +% seed),
+            swap(blk[1]) ^ (swap(blk[3]) -% seed),
+        );
+    }
+
+    const Accumulator = extern struct {
+        consumed: usize = 0,
+        seed: u64,
+        secret: [192]u8 = undefined,
+        state: Block = Block{
+            XxHash32.prime_3,
+            XxHash64.prime_1,
+            XxHash64.prime_2,
+            XxHash64.prime_3,
+            XxHash64.prime_4,
+            XxHash32.prime_2,
+            XxHash64.prime_5,
+            XxHash32.prime_1,
+        },
+
+        inline fn init(seed: u64) Accumulator {
+            var self = Accumulator{ .seed = seed };
+            for (
+                std.mem.bytesAsSlice(Block, &self.secret),
+                std.mem.bytesAsSlice(Block, &default_secret),
+            ) |*dst, src| {
+                dst.* = swap(swap(src) +% Block{
+                    seed, @as(u64, 0) -% seed,
+                    seed, @as(u64, 0) -% seed,
+                    seed, @as(u64, 0) -% seed,
+                    seed, @as(u64, 0) -% seed,
+                });
+            }
+            return self;
+        }
+
+        inline fn round(
+            noalias state: *Block,
+            noalias input_block: *align(1) const Block,
+            noalias secret_block: *align(1) const Block,
+        ) void {
+            const data = swap(input_block.*);
+            const mixed = data ^ swap(secret_block.*);
+            state.* +%= (mixed & @as(Block, @splat(0xffffffff))) *% (mixed >> @splat(32));
+            state.* +%= @shuffle(u64, data, undefined, [_]i32{ 1, 0, 3, 2, 5, 4, 7, 6 });
+        }
+
+        fn accumulate(noalias self: *Accumulator, blocks: []align(1) const Block) void {
+            const secret = std.mem.bytesAsSlice(u64, self.secret[self.consumed * 8 ..]);
+            for (blocks, secret[0..blocks.len]) |*input_block, *secret_block| {
+                @prefetch(@as([*]const u8, @ptrCast(input_block)) + 320, .{});
+                round(&self.state, input_block, @ptrCast(secret_block));
+            }
+        }
+
+        fn scramble(self: *Accumulator) void {
+            const secret_block: Block = @bitCast(self.secret[192 - @sizeOf(Block) .. 192].*);
+            self.state ^= self.state >> @splat(47);
+            self.state ^= swap(secret_block);
+            self.state *%= @as(Block, @splat(XxHash32.prime_1));
+        }
+
+        fn consume(noalias self: *Accumulator, input_blocks: []align(1) const Block) void {
+            const blocks_per_scramble = 1024 / @sizeOf(Block);
+            std.debug.assert(self.consumed <= blocks_per_scramble);
+
+            var blocks = input_blocks;
+            var blocks_until_scramble = blocks_per_scramble - self.consumed;
+            while (blocks.len >= blocks_until_scramble) {
+                self.accumulate(blocks[0..blocks_until_scramble]);
+                self.scramble();
+
+                self.consumed = 0;
+                blocks = blocks[blocks_until_scramble..];
+                blocks_until_scramble = blocks_per_scramble;
+            }
+
+            self.accumulate(blocks);
+            self.consumed += blocks.len;
+        }
+
+        fn digest(noalias self: *Accumulator, total_len: u64, noalias last_block: *align(1) const Block) u64 {
+            const secret_block = self.secret[192 - @sizeOf(Block) - 7 ..][0..@sizeOf(Block)];
+            round(&self.state, last_block, @ptrCast(secret_block));
+
+            const merge_block: Block = @bitCast(self.secret[11 .. 11 + @sizeOf(Block)].*);
+            self.state ^= swap(merge_block);
+
+            var result = XxHash64.prime_1 *% total_len;
+            inline for (0..4) |i| {
+                result +%= fold(self.state[i * 2], self.state[i * 2 + 1]);
+            }
+            return avalanche(.h3, result);
+        }
+    };
+
+    // Public API - Oneshot
+
+    pub fn hash(seed: u64, input: anytype) u64 {
+        validateType(@TypeOf(input));
+
+        const secret = &default_secret;
+        if (input.len > 240) return hashLong(seed, input);
+        if (input.len > 128) return hash240(seed, input, secret);
+        if (input.len > 16) return hash128(seed, input, secret);
+        if (input.len > 8) return hash16(seed, input, secret);
+        if (input.len > 3) return hash8(seed, input, secret);
+        if (input.len > 0) return hash3(seed, input, secret);
+
+        const flip: [2]u64 = @bitCast(secret[56..72].*);
+        const key = swap(flip[0]) ^ swap(flip[1]);
+        return avalanche(.h64, seed ^ key);
+    }
+
+    fn hash3(seed: u64, input: anytype, noalias secret: *const [192]u8) u64 {
+        @setCold(true);
+        std.debug.assert(input.len > 0 and input.len < 4);
+
+        const flip: [2]u32 = @bitCast(secret[0..8].*);
+        const blk: u32 = @bitCast([_]u8{
+            input[input.len - 1],
+            @truncate(input.len),
+            input[0],
+            input[input.len / 2],
+        });
+
+        const key = @as(u64, swap(flip[0]) ^ swap(flip[1])) +% seed;
+        return avalanche(.h64, key ^ swap(blk));
+    }
+
+    fn hash8(seed: u64, input: anytype, noalias secret: *const [192]u8) u64 {
+        @setCold(true);
+        std.debug.assert(input.len >= 4 and input.len <= 8);
+
+        const flip: [2]u64 = @bitCast(secret[8..24].*);
+        const blk: [2]u32 = @bitCast([_][4]u8{
+            input[0..4].*,
+            input[input.len - 4 ..][0..4].*,
+        });
+
+        const mixed = seed ^ (@as(u64, @byteSwap(@as(u32, @truncate(seed)))) << 32);
+        const key = (swap(flip[0]) ^ swap(flip[1])) -% mixed;
+        const combined = (@as(u64, swap(blk[0])) << 32) +% swap(blk[1]);
+        return avalanche(.{ .rrmxmx = input.len }, key ^ combined);
+    }
+
+    fn hash16(seed: u64, input: anytype, noalias secret: *const [192]u8) u64 {
+        @setCold(true);
+        std.debug.assert(input.len > 8 and input.len <= 16);
+
+        const flip: [4]u64 = @bitCast(secret[24..56].*);
+        const blk: [2]u64 = @bitCast([_][8]u8{
+            input[0..8].*,
+            input[input.len - 8 ..][0..8].*,
+        });
+
+        const lo = swap(blk[0]) ^ ((swap(flip[0]) ^ swap(flip[1])) +% seed);
+        const hi = swap(blk[1]) ^ ((swap(flip[2]) ^ swap(flip[3])) -% seed);
+        const combined = @as(u64, input.len) +% @byteSwap(lo) +% hi +% fold(lo, hi);
+        return avalanche(.h3, combined);
+    }
+
+    fn hash128(seed: u64, input: anytype, noalias secret: *const [192]u8) u64 {
+        @setCold(true);
+        std.debug.assert(input.len > 16 and input.len <= 128);
+
+        var acc = XxHash64.prime_1 *% @as(u64, input.len);
+        inline for (0..4) |i| {
+            const in_offset = 48 - (i * 16);
+            const scrt_offset = 96 - (i * 32);
+            if (input.len > scrt_offset) {
+                acc +%= mix16(seed, input[in_offset..], secret[scrt_offset..]);
+                acc +%= mix16(seed, input[input.len - (in_offset + 16) ..], secret[scrt_offset + 16 ..]);
+            }
+        }
+        return avalanche(.h3, acc);
+    }
+
+    fn hash240(seed: u64, input: anytype, noalias secret: *const [192]u8) u64 {
+        @setCold(true);
+        std.debug.assert(input.len > 128 and input.len <= 240);
+
+        var acc = XxHash64.prime_1 *% @as(u64, input.len);
+        inline for (0..8) |i| {
+            acc +%= mix16(seed, input[i * 16 ..], secret[i * 16 ..]);
+        }
+
+        var acc_end = mix16(seed, input[input.len - 16 ..], secret[136 - 17 ..]);
+        for (8..(input.len / 16)) |i| {
+            acc_end +%= mix16(seed, input[i * 16 ..], secret[((i - 8) * 16) + 3 ..]);
+            disableAutoVectorization(i);
+        }
+
+        acc = avalanche(.h3, acc) +% acc_end;
+        return avalanche(.h3, acc);
+    }
+
+    noinline fn hashLong(seed: u64, input: []const u8) u64 {
+        @setCold(true);
+        std.debug.assert(input.len >= 240);
+
+        const block_count = ((input.len - 1) / @sizeOf(Block)) * @sizeOf(Block);
+        const last_block = input[input.len - @sizeOf(Block) ..][0..@sizeOf(Block)];
+
+        var acc = Accumulator.init(seed);
+        acc.consume(std.mem.bytesAsSlice(Block, input[0..block_count]));
+        return acc.digest(input.len, @ptrCast(last_block));
+    }
+
+    // Public API - Streaming
+
+    buffered: usize = 0,
+    buffer: [256]u8 = undefined,
+    total_len: usize = 0,
+    accumulator: Accumulator,
+
+    pub fn init(seed: u64) XxHash3 {
+        return .{ .accumulator = Accumulator.init(seed) };
+    }
+
+    pub fn update(self: *XxHash3, input: anytype) void {
+        validateType(@TypeOf(input));
+
+        self.total_len += input.len;
+        std.debug.assert(self.buffered <= self.buffer.len);
+
+        // Copy the input into the buffer if we haven't filled it up yet.
+        const remaining = self.buffer.len - self.buffered;
+        if (input.len <= remaining) {
+            @memcpy(self.buffer[self.buffered..][0..input.len], input);
+            self.buffered += input.len;
+            return;
+        }
+
+        // Input will overflow the buffer. Fill up the buffer with some input and consume it.
+        var consumable: []const u8 = input;
+        if (self.buffered > 0) {
+            @memcpy(self.buffer[self.buffered..], consumable[0..remaining]);
+            consumable = consumable[remaining..];
+
+            self.accumulator.consume(std.mem.bytesAsSlice(Block, &self.buffer));
+            self.buffered = 0;
+        }
+
+        // The input isn't small enough to fit in the buffer. Consume it directly.
+        if (consumable.len > self.buffer.len) {
+            const block_count = ((consumable.len - 1) / @sizeOf(Block)) * @sizeOf(Block);
+            self.accumulator.consume(std.mem.bytesAsSlice(Block, consumable[0..block_count]));
+            consumable = consumable[block_count..];
+
+            // In case we consume all remaining input, write the last block to end of the buffer
+            // to populate the last_block_copy in final() similar to hashLong()'s last_block.
+            @memcpy(
+                self.buffer[self.buffer.len - @sizeOf(Block) .. self.buffer.len],
+                (consumable.ptr - @sizeOf(Block))[0..@sizeOf(Block)],
+            );
+        }
+
+        // Copy in any remaining input into the buffer.
+        std.debug.assert(consumable.len <= self.buffer.len);
+        @memcpy(self.buffer[0..consumable.len], consumable);
+        self.buffered = consumable.len;
+    }
+
+    pub fn final(self: *XxHash3) u64 {
+        std.debug.assert(self.buffered <= self.total_len);
+        std.debug.assert(self.buffered <= self.buffer.len);
+
+        // Use Oneshot hashing for smaller sizes as it doesn't use Accumulator like hashLong.
+        if (self.total_len <= 240) {
+            return hash(self.accumulator.seed, self.buffer[0..self.total_len]);
+        }
+
+        // Make a copy of the Accumulator state in case `self` needs to update() / be used later.
+        var accumulator_copy = self.accumulator;
+        var last_block_copy: [@sizeOf(Block)]u8 = undefined;
+
+        // Digest the last block onthe Accumulator copy.
+        return accumulator_copy.digest(self.total_len, last_block: {
+            if (self.buffered >= @sizeOf(Block)) {
+                const block_count = ((self.buffered - 1) / @sizeOf(Block)) * @sizeOf(Block);
+                accumulator_copy.consume(std.mem.bytesAsSlice(Block, self.buffer[0..block_count]));
+                break :last_block @ptrCast(self.buffer[self.buffered - @sizeOf(Block) ..][0..@sizeOf(Block)]);
+            } else {
+                const remaining = @sizeOf(Block) - self.buffered;
+                @memcpy(last_block_copy[0..remaining], self.buffer[self.buffer.len - remaining ..][0..remaining]);
+                @memcpy(last_block_copy[remaining..][0..self.buffered], self.buffer[0..self.buffered]);
+                break :last_block @ptrCast(&last_block_copy);
+            }
+        });
+    }
+};
+
+const verify = @import("verify.zig");
+
 fn validateType(comptime T: type) void {
     comptime {
         if (!((std.meta.trait.isSlice(T) or
@@ -438,16 +794,67 @@ fn validateType(comptime T: type) void {
     }
 }
 
-const verify = @import("verify.zig");
-
 fn testExpect(comptime H: type, seed: anytype, input: []const u8, expected: u64) !void {
-    try expectEqual(expected, H.hash(0, input));
+    try expectEqual(expected, H.hash(seed, input));
 
     var hasher = H.init(seed);
     hasher.update(input);
     try expectEqual(expected, hasher.final());
 }
 
+test "xxhash3" {
+    const H = XxHash3;
+    // Non-Seeded Tests
+    try testExpect(H, 0, "", 0x2d06800538d394c2);
+    try testExpect(H, 0, "a", 0xe6c632b61e964e1f);
+    try testExpect(H, 0, "abc", 0x78af5f94892f3950);
+    try testExpect(H, 0, "message", 0x0b1ca9b8977554fa);
+    try testExpect(H, 0, "message digest", 0x160d8e9329be94f9);
+    try testExpect(H, 0, "abcdefghijklmnopqrstuvwxyz", 0x810f9ca067fbb90c);
+    try testExpect(H, 0, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", 0x643542bb51639cb2);
+    try testExpect(H, 0, "12345678901234567890123456789012345678901234567890123456789012345678901234567890", 0x7f58aa2520c681f9);
+    try testExpect(H, 0, "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678", 0xb66ea795b5edc38c);
+    try testExpect(H, 0, "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890", 0x8845e0b1b57330de);
+    try testExpect(H, 0, "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123123", 0xf031f373d63c5653);
+    try testExpect(H, 0, "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890", 0xf1bf601f9d868dce);
+
+    // Seeded Tests
+    try testExpect(H, 1, "", 0x4dc5b0cc826f6703);
+    try testExpect(H, 1, "a", 0xd2f6d0996f37a720);
+    try testExpect(H, 1, "abc", 0x6b4467b443c76228);
+    try testExpect(H, 1, "message", 0x73fb1cf20d561766);
+    try testExpect(H, 1, "message digest", 0xfe71a82a70381174);
+    try testExpect(H, 1, "abcdefghijklmnopqrstuvwxyz", 0x902a2c2d016a37ba);
+    try testExpect(H, 1, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", 0xbf552e540c5c6882);
+    try testExpect(H, 1, "12345678901234567890123456789012345678901234567890123456789012345678901234567890", 0xf2ca33235a6b865b);
+    try testExpect(H, 1, "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678", 0x6ef5cf958ba52c4);
+    try testExpect(H, 1, "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890", 0xfbc5f9c53d21cb2f);
+    try testExpect(H, 1, "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123123", 0x48682aca3b1c5c18);
+    try testExpect(H, 1, "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890", 0x3903c5437fc4e726);
+}
+
+test "xxhash3 smhasher" {
+    const Test = struct {
+        fn do() !void {
+            try expectEqual(verify.smhasher(XxHash3.hash), 0x9a636405);
+        }
+    };
+    try Test.do();
+    @setEvalBranchQuota(75000);
+    comptime try Test.do();
+}
+
+test "xxhash3 iterative api" {
+    const Test = struct {
+        fn do() !void {
+            try verify.iterativeApi(XxHash3);
+        }
+    };
+    try Test.do();
+    @setEvalBranchQuota(30000);
+    comptime try Test.do();
+}
+
 test "xxhash64" {
     const H = XxHash64;
     try testExpect(H, 0, "", 0xef46db3751d8e999);
lib/std/hash.zig
@@ -33,6 +33,7 @@ const wyhash = @import("hash/wyhash.zig");
 pub const Wyhash = wyhash.Wyhash;
 
 const xxhash = @import("hash/xxhash.zig");
+pub const XxHash3 = xxhash.XxHash3;
 pub const XxHash64 = xxhash.XxHash64;
 pub const XxHash32 = xxhash.XxHash32;