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std.hash: use std.math.rotl in Xxhash64 and Xxhash32

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This commit is contained in:
dweiller 2023-02-21 11:30:59 +11:00
parent a74f800dd7
commit a34c2de7bc
1 changed files with 12 additions and 12 deletions
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24
lib/std/hash/xxhash.zig
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@ -2,9 +2,7 @@ const std = @import("std");
const mem = std.mem;
const expectEqual = std.testing.expectEqual;
inline fn rotl(comptime count: comptime_int, value: anytype) @TypeOf(value) {
return (value << count) | (value >> (@bitSizeOf(@TypeOf(value)) - count));
}
const rotl = std.math.rotl;
pub const XxHash64 = struct {
acc1: u64,
@ -71,7 +69,7 @@ pub const XxHash64 = struct {
inline fn round(acc: u64, lane: u64) u64 {
const a = acc +% (lane *% prime_2);
const b = rotl(31, a);
const b = rotl(u64, a, 31);
return b *% prime_1;
}
@ -81,7 +79,8 @@ pub const XxHash64 = struct {
if (self.byte_count < 32) {
acc = self.seed +% prime_5;
} else {
acc = rotl(1, self.acc1) +% rotl(7, self.acc2) +% rotl(12, self.acc3) +% rotl(18, self.acc4);
acc = rotl(u64, self.acc1, 1) +% rotl(u64, self.acc2, 7) +%
rotl(u64, self.acc3, 12) +% rotl(u64, self.acc4, 18);
acc = mergeAccumulator(acc, self.acc1);
acc = mergeAccumulator(acc, self.acc2);
acc = mergeAccumulator(acc, self.acc3);
@ -94,14 +93,14 @@ pub const XxHash64 = struct {
while (pos + 8 <= self.buf_len) : (pos += 8) {
const lane = mem.readIntLittle(u64, self.buf[pos..][0..8]);
acc ^= round(0, lane);
acc = rotl(27, acc) *% prime_1;
acc = rotl(u64, acc, 27) *% prime_1;
acc +%= prime_4;
}
if (pos + 4 <= self.buf_len) {
const lane = @as(u64, mem.readIntLittle(u32, self.buf[pos..][0..4]));
acc ^= lane *% prime_1;
acc = rotl(23, acc) *% prime_2;
acc = rotl(u64, acc, 23) *% prime_2;
acc +%= prime_3;
pos += 4;
}
@ -109,7 +108,7 @@ pub const XxHash64 = struct {
while (pos < self.buf_len) : (pos += 1) {
const lane = @as(u64, self.buf[pos]);
acc ^= lane *% prime_5;
acc = rotl(11, acc) *% prime_1;
acc = rotl(u64, acc, 11) *% prime_1;
}
acc ^= acc >> 33;
@ -199,7 +198,7 @@ pub const XxHash32 = struct {
inline fn round(acc: u32, lane: u32) u32 {
const a = acc +% (lane *% prime_2);
const b = rotl(13, a);
const b = rotl(u32, a, 13);
return b *% prime_1;
}
@ -209,7 +208,8 @@ pub const XxHash32 = struct {
if (self.byte_count < 16) {
acc = self.seed +% prime_5;
} else {
acc = rotl(1, self.acc1) +% rotl(7, self.acc2) +% rotl(12, self.acc3) +% rotl(18, self.acc4);
acc = rotl(u32, self.acc1, 1) +% rotl(u32, self.acc2, 7) +%
rotl(u32, self.acc3, 12) +% rotl(u32, self.acc4, 18);
}
acc = acc +% @intCast(u32, self.byte_count) +% @intCast(u32, self.buf_len);
@ -218,13 +218,13 @@ pub const XxHash32 = struct {
while (pos + 4 <= self.buf_len) : (pos += 4) {
const lane = mem.readIntLittle(u32, self.buf[pos..][0..4]);
acc +%= lane *% prime_3;
acc = rotl(17, acc) *% prime_4;
acc = rotl(u32, acc, 17) *% prime_4;
}
while (pos < self.buf_len) : (pos += 1) {
const lane = @as(u32, self.buf[pos]);
acc +%= lane *% prime_5;
acc = rotl(11, acc) *% prime_1;
acc = rotl(u32, acc, 11) *% prime_1;
}
acc ^= acc >> 15;