zig fmt fix

crates/compiler/builtins/bitcode/src/hash.zig

@@ -0,0 +1,254 @@
+// 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 std = @import("std");
+const str = @import("str.zig");
+const mem = std.mem;
+
+pub fn wyhash(seed: u64, bytes: ?[*]const u8, length: usize) callconv(.C) u64 {
+    if (bytes) |nonnull| {
+        const slice = nonnull[0..length];
+        return wyhash_hash(seed, slice);
+    } else {
+        return 42;
+    }
+}
+
+pub fn wyhash_rocstr(seed: u64, input: str.RocStr) callconv(.C) u64 {
+    return wyhash_hash(seed, input.asSlice());
+}
+
+const primes = [_]u64{
+    0xa0761d6478bd642f,
+    0xe7037ed1a0b428db,
+    0x8ebc6af09c88c6e3,
+    0x589965cc75374cc3,
+    0x1d8e4e27c47d124f,
+};
+
+fn read_bytes(comptime bytes: u8, data: []const u8) u64 {
+    const T = std.meta.Int(.unsigned, 8 * bytes);
+    return mem.readIntLittle(T, data[0..bytes]);
+}
+
+fn read_8bytes_swapped(data: []const u8) u64 {
+    return (read_bytes(4, data) << 32 | read_bytes(4, data[4..]));
+}
+
+fn mum(a: u64, b: u64) u64 {
+    var r = std.math.mulWide(u64, a, b);
+    r = (r >> 64) ^ r;
+    return @as(u64, @truncate(r));
+}
+
+fn mix0(a: u64, b: u64, seed: u64) u64 {
+    return mum(a ^ seed ^ primes[0], b ^ seed ^ primes[1]);
+}
+
+fn mix1(a: u64, b: u64, seed: u64) u64 {
+    return mum(a ^ seed ^ primes[2], b ^ seed ^ primes[3]);
+}
+
+// Wyhash version which does not store internal state for handling partial buffers.
+// This is needed so that we can maximize the speed for the short key case, which will
+// use the non-iterative api which the public Wyhash exposes.
+const WyhashStateless = struct {
+    seed: u64,
+    msg_len: usize,
+
+    pub fn init(seed: u64) WyhashStateless {
+        return WyhashStateless{
+            .seed = seed,
+            .msg_len = 0,
+        };
+    }
+
+    fn round(self: *WyhashStateless, b: []const u8) void {
+        std.debug.assert(b.len == 32);
+
+        self.seed = mix0(
+            read_bytes(8, b[0..]),
+            read_bytes(8, b[8..]),
+            self.seed,
+        ) ^ mix1(
+            read_bytes(8, b[16..]),
+            read_bytes(8, b[24..]),
+            self.seed,
+        );
+    }
+
+    pub fn update(self: *WyhashStateless, b: []const u8) void {
+        std.debug.assert(b.len % 32 == 0);
+
+        var off: usize = 0;
+        while (off < b.len) : (off += 32) {
+            @call(.{ .modifier = .always_inline }, self.round, .{b[off .. off + 32]});
+        }
+
+        self.msg_len += b.len;
+    }
+
+    pub fn final(self: *WyhashStateless, b: []const u8) u64 {
+        std.debug.assert(b.len < 32);
+
+        const seed = self.seed;
+        const rem_len = @as(u5, @intCast(b.len));
+        const rem_key = b[0..rem_len];
+
+        self.seed = switch (rem_len) {
+            0 => seed,
+            1 => mix0(read_bytes(1, rem_key), primes[4], seed),
+            2 => mix0(read_bytes(2, rem_key), primes[4], seed),
+            3 => mix0((read_bytes(2, rem_key) << 8) | read_bytes(1, rem_key[2..]), primes[4], seed),
+            4 => mix0(read_bytes(4, rem_key), primes[4], seed),
+            5 => mix0((read_bytes(4, rem_key) << 8) | read_bytes(1, rem_key[4..]), primes[4], seed),
+            6 => mix0((read_bytes(4, rem_key) << 16) | read_bytes(2, rem_key[4..]), primes[4], seed),
+            7 => mix0((read_bytes(4, rem_key) << 24) | (read_bytes(2, rem_key[4..]) << 8) | read_bytes(1, rem_key[6..]), primes[4], seed),
+            8 => mix0(read_8bytes_swapped(rem_key), primes[4], seed),
+            9 => mix0(read_8bytes_swapped(rem_key), read_bytes(1, rem_key[8..]), seed),
+            10 => mix0(read_8bytes_swapped(rem_key), read_bytes(2, rem_key[8..]), seed),
+            11 => mix0(read_8bytes_swapped(rem_key), (read_bytes(2, rem_key[8..]) << 8) | read_bytes(1, rem_key[10..]), seed),
+            12 => mix0(read_8bytes_swapped(rem_key), read_bytes(4, rem_key[8..]), seed),
+            13 => mix0(read_8bytes_swapped(rem_key), (read_bytes(4, rem_key[8..]) << 8) | read_bytes(1, rem_key[12..]), seed),
+            14 => mix0(read_8bytes_swapped(rem_key), (read_bytes(4, rem_key[8..]) << 16) | read_bytes(2, rem_key[12..]), seed),
+            15 => mix0(read_8bytes_swapped(rem_key), (read_bytes(4, rem_key[8..]) << 24) | (read_bytes(2, rem_key[12..]) << 8) | read_bytes(1, rem_key[14..]), seed),
+            16 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed),
+            17 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_bytes(1, rem_key[16..]), primes[4], seed),
+            18 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_bytes(2, rem_key[16..]), primes[4], seed),
+            19 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1((read_bytes(2, rem_key[16..]) << 8) | read_bytes(1, rem_key[18..]), primes[4], seed),
+            20 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_bytes(4, rem_key[16..]), primes[4], seed),
+            21 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1((read_bytes(4, rem_key[16..]) << 8) | read_bytes(1, rem_key[20..]), primes[4], seed),
+            22 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1((read_bytes(4, rem_key[16..]) << 16) | read_bytes(2, rem_key[20..]), primes[4], seed),
+            23 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1((read_bytes(4, rem_key[16..]) << 24) | (read_bytes(2, rem_key[20..]) << 8) | read_bytes(1, rem_key[22..]), primes[4], seed),
+            24 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_8bytes_swapped(rem_key[16..]), primes[4], seed),
+            25 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_8bytes_swapped(rem_key[16..]), read_bytes(1, rem_key[24..]), seed),
+            26 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_8bytes_swapped(rem_key[16..]), read_bytes(2, rem_key[24..]), seed),
+            27 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_8bytes_swapped(rem_key[16..]), (read_bytes(2, rem_key[24..]) << 8) | read_bytes(1, rem_key[26..]), seed),
+            28 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_8bytes_swapped(rem_key[16..]), read_bytes(4, rem_key[24..]), seed),
+            29 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_8bytes_swapped(rem_key[16..]), (read_bytes(4, rem_key[24..]) << 8) | read_bytes(1, rem_key[28..]), seed),
+            30 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_8bytes_swapped(rem_key[16..]), (read_bytes(4, rem_key[24..]) << 16) | read_bytes(2, rem_key[28..]), seed),
+            31 => mix0(read_8bytes_swapped(rem_key), read_8bytes_swapped(rem_key[8..]), seed) ^ mix1(read_8bytes_swapped(rem_key[16..]), (read_bytes(4, rem_key[24..]) << 24) | (read_bytes(2, rem_key[28..]) << 8) | read_bytes(1, rem_key[30..]), seed),
+        };
+
+        self.msg_len += b.len;
+        return mum(self.seed ^ self.msg_len, primes[4]);
+    }
+
+    pub fn hash(seed: u64, input: []const u8) u64 {
+        const aligned_len = input.len - (input.len % 32);
+
+        var c = WyhashStateless.init(seed);
+        @call(.{ .modifier = .always_inline }, c.update, .{input[0..aligned_len]});
+        return @call(.{ .modifier = .always_inline }, c.final, .{input[aligned_len..]});
+    }
+};
+
+/// Fast non-cryptographic 64bit hash function.
+/// See https://github.com/wangyi-fudan/wyhash
+pub const Wyhash = struct {
+    state: WyhashStateless,
+
+    buf: [32]u8,
+    buf_len: usize,
+
+    pub fn init(seed: u64) Wyhash {
+        return Wyhash{
+            .state = WyhashStateless.init(seed),
+            .buf = undefined,
+            .buf_len = 0,
+        };
+    }
+
+    pub fn update(self: *Wyhash, b: []const u8) void {
+        var off: usize = 0;
+
+        if (self.buf_len != 0 and self.buf_len + b.len >= 32) {
+            off += 32 - self.buf_len;
+            mem.copy(u8, self.buf[self.buf_len..], b[0..off]);
+            self.state.update(self.buf[0..]);
+            self.buf_len = 0;
+        }
+
+        const remain_len = b.len - off;
+        const aligned_len = remain_len - (remain_len % 32);
+        self.state.update(b[off .. off + aligned_len]);
+
+        mem.copy(u8, self.buf[self.buf_len..], b[off + aligned_len ..]);
+        self.buf_len += @as(u8, @intCast(b[off + aligned_len ..].len));
+    }
+
+    pub fn final(self: *Wyhash) u64 {
+        // const seed = self.state.seed;
+        // const rem_len = @intCast(u5, self.buf_len);
+        const rem_key = self.buf[0..self.buf_len];
+
+        return self.state.final(rem_key);
+    }
+
+    pub fn hash(seed: u64, input: []const u8) u64 {
+        return WyhashStateless.hash(seed, input);
+    }
+};
+
+fn wyhash_hash(seed: u64, input: []const u8) u64 {
+    return Wyhash.hash(seed, input);
+}
+
+const expectEqual = std.testing.expectEqual;
+
+test "test vectors" {
+    const hash = Wyhash.hash;
+
+    try expectEqual(hash(0, ""), 0x0);
+    try expectEqual(hash(1, "a"), 0xbed235177f41d328);
+    try expectEqual(hash(2, "abc"), 0xbe348debe59b27c3);
+    try expectEqual(hash(3, "message digest"), 0x37320f657213a290);
+    try expectEqual(hash(4, "abcdefghijklmnopqrstuvwxyz"), 0xd0b270e1d8a7019c);
+    try expectEqual(hash(5, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"), 0x602a1894d3bbfe7f);
+    try expectEqual(hash(6, "12345678901234567890123456789012345678901234567890123456789012345678901234567890"), 0x829e9c148b75970e);
+}
+
+test "test vectors streaming" {
+    var wh = Wyhash.init(5);
+    for ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") |e| {
+        wh.update(mem.asBytes(&e));
+    }
+    try expectEqual(wh.final(), 0x602a1894d3bbfe7f);
+
+    const pattern = "1234567890";
+    const count = 8;
+    const result = 0x829e9c148b75970e;
+    try expectEqual(Wyhash.hash(6, pattern ** 8), result);
+
+    wh = Wyhash.init(6);
+    var i: u32 = 0;
+    while (i < count) : (i += 1) {
+        wh.update(pattern);
+    }
+    try expectEqual(wh.final(), result);
+}
+
+test "iterative non-divisible update" {
+    var buf: [8192]u8 = undefined;
+    for (buf, 0..) |*e, i| {
+        e.* = @as(u8, @truncate(i));
+    }
+
+    const seed = 0x128dad08f;
+
+    var end: usize = 32;
+    while (end < buf.len) : (end += 32) {
+        const non_iterative_hash = Wyhash.hash(seed, buf[0..end]);
+
+        var wy = Wyhash.init(seed);
+        var i: usize = 0;
+        while (i < end) : (i += 33) {
+            wy.update(buf[i..std.math.min(i + 33, end)]);
+        }
+        const iterative_hash = wy.final();
+
+        try std.testing.expectEqual(iterative_hash, non_iterative_hash);
+    }
+}