diff --git a/lib/std/crypto/ghash_polyval.zig b/lib/std/crypto/ghash_polyval.zig index 2bb118c791..46645d710f 100644 --- a/lib/std/crypto/ghash_polyval.zig +++ b/lib/std/crypto/ghash_polyval.zig @@ -155,8 +155,18 @@ fn Hash(comptime endian: std.builtin.Endian, comptime shift_key: bool) type { } } - // Software carryless multiplication of two 64-bit integers. - fn clmulSoft(x_: u128, y_: u128, comptime half: Selector) u128 { + /// clmulSoft128_64 is faster on platforms with no native 128-bit registers. + const clmulSoft = switch (builtin.cpu.arch) { + .wasm32, .wasm64 => clmulSoft128_64, + else => impl: { + const vector_size = std.simd.suggestVectorSize(u128) orelse 0; + if (vector_size < 128) break :impl clmulSoft128_64; + break :impl clmulSoft128; + }, + }; + + // Software carryless multiplication of two 64-bit integers using native 128-bit registers. + fn clmulSoft128(x_: u128, y_: u128, comptime half: Selector) u128 { const x = @truncate(u64, if (half == .hi or half == .hi_lo) x_ >> 64 else x_); const y = @truncate(u64, if (half == .hi) y_ >> 64 else y_); @@ -186,6 +196,40 @@ fn Hash(comptime endian: std.builtin.Endian, comptime shift_key: bool) type { (z3 & 0x88888888888888888888888888888888) ^ extra; } + // Software carryless multiplication of two 32-bit integers. + fn clmulSoft32(x: u32, y: u32) u64 { + const mulWide = math.mulWide; + const a0 = x & 0x11111111; + const a1 = x & 0x22222222; + const a2 = x & 0x44444444; + const a3 = x & 0x88888888; + const b0 = y & 0x11111111; + const b1 = y & 0x22222222; + const b2 = y & 0x44444444; + const b3 = y & 0x88888888; + const c0 = mulWide(u32, a0, b0) ^ mulWide(u32, a1, b3) ^ mulWide(u32, a2, b2) ^ mulWide(u32, a3, b1); + const c1 = mulWide(u32, a0, b1) ^ mulWide(u32, a1, b0) ^ mulWide(u32, a2, b3) ^ mulWide(u32, a3, b2); + const c2 = mulWide(u32, a0, b2) ^ mulWide(u32, a1, b1) ^ mulWide(u32, a2, b0) ^ mulWide(u32, a3, b3); + const c3 = mulWide(u32, a0, b3) ^ mulWide(u32, a1, b2) ^ mulWide(u32, a2, b1) ^ mulWide(u32, a3, b0); + return (c0 & 0x1111111111111111) | (c1 & 0x2222222222222222) | (c2 & 0x4444444444444444) | (c3 & 0x8888888888888888); + } + + // Software carryless multiplication of two 128-bit integers using 64-bit registers. + fn clmulSoft128_64(x_: u128, y_: u128, comptime half: Selector) u128 { + const a = @truncate(u64, if (half == .hi or half == .hi_lo) x_ >> 64 else x_); + const b = @truncate(u64, if (half == .hi) y_ >> 64 else y_); + const a0 = @truncate(u32, a); + const a1 = @truncate(u32, a >> 32); + const b0 = @truncate(u32, b); + const b1 = @truncate(u32, b >> 32); + const lo = clmulSoft32(a0, b0); + const hi = clmulSoft32(a1, b1); + const mid = clmulSoft32(a0 ^ a1, b0 ^ b1) ^ lo ^ hi; + const res_lo = lo ^ (mid << 32); + const res_hi = hi ^ (mid >> 32); + return @as(u128, res_lo) | (@as(u128, res_hi) << 64); + } + const I256 = struct { hi: u128, lo: u128,