tiny.simd.logical

1const std = @import("std");23pub fn bitNot(comptime D: type, value: D.Vector) D.Vector {4    const UVector = unsignedVector(D);5    const bits: UVector = @bitCast(value);6    return @bitCast(~bits);7}89pub fn bitAnd(comptime D: type, a: D.Vector, b: D.Vector) D.Vector {10    const UVector = unsignedVector(D);11    const a_bits: UVector = @bitCast(a);12    const b_bits: UVector = @bitCast(b);13    return @bitCast(a_bits & b_bits);14}1516pub fn andNot(comptime D: type, a: D.Vector, b: D.Vector) D.Vector {17    return bitAnd(D, bitNot(D, a), b);18}1920pub fn bitOr(comptime D: type, a: D.Vector, b: D.Vector) D.Vector {21    const UVector = unsignedVector(D);22    const a_bits: UVector = @bitCast(a);23    const b_bits: UVector = @bitCast(b);24    return @bitCast(a_bits | b_bits);25}2627pub fn bitXor(comptime D: type, a: D.Vector, b: D.Vector) D.Vector {28    const UVector = unsignedVector(D);29    const a_bits: UVector = @bitCast(a);30    const b_bits: UVector = @bitCast(b);31    return @bitCast(a_bits ^ b_bits);32}3334pub fn or3(comptime D: type, a: D.Vector, b: D.Vector, c: D.Vector) D.Vector {35    return bitOr(D, a, bitOr(D, b, c));36}3738pub fn xor3(comptime D: type, a: D.Vector, b: D.Vector, c: D.Vector) D.Vector {39    return bitXor(D, a, bitXor(D, b, c));40}4142pub fn orAnd(comptime D: type, o: D.Vector, a: D.Vector, b: D.Vector) D.Vector {43    return bitOr(D, o, bitAnd(D, a, b));44}4546pub fn xorAndNot(comptime D: type, x: D.Vector, a: D.Vector, b: D.Vector) D.Vector {47    return bitXor(D, x, andNot(D, a, b));48}4950pub fn andXor(comptime D: type, a: D.Vector, x: D.Vector, y: D.Vector) D.Vector {51    return bitAnd(D, a, bitXor(D, x, y));52}5354pub fn maskedOrOr(55    comptime D: type,56    inactive: D.Vector,57    mask: D.Mask,58    a: D.Vector,59    b: D.Vector,60) D.Vector {61    return @select(D.Lane, mask, bitOr(D, a, b), inactive);62}6364pub fn maskedOr(comptime D: type, mask: D.Mask, a: D.Vector, b: D.Vector) D.Vector {65    return maskedOrOr(D, @splat(0), mask, a, b);66}6768pub fn maskedXorOr(69    comptime D: type,70    inactive: D.Vector,71    mask: D.Mask,72    a: D.Vector,73    b: D.Vector,74) D.Vector {75    return @select(D.Lane, mask, bitXor(D, a, b), inactive);76}7778pub fn maskedXor(comptime D: type, mask: D.Mask, a: D.Vector, b: D.Vector) D.Vector {79    return maskedXorOr(D, @splat(0), mask, a, b);80}8182pub fn testBit(comptime D: type, value: D.Vector, bit: D.Vector) D.Mask {83    if (comptime @typeInfo(D.Lane) != .int) {84        @compileError("testBit requires integer lanes");85    }86    return bitAnd(D, value, bit) == bit;87}8889pub fn allBitsZero(comptime D: type, value: D.Vector) bool {90    const UVector = unsignedVector(D);91    const bits: UVector = @bitCast(value);92    return !@reduce(.Or, bits != @as(UVector, @splat(0)));93}9495pub fn allBitsOne(comptime D: type, value: D.Vector) bool {96    const UVector = unsignedVector(D);97    const bits: UVector = @bitCast(value);98    return !@reduce(.Or, bits != @as(UVector, @splat(~@as(unsignedLane(D.Lane), 0))));99}100101fn unsignedVector(comptime D: type) type {102    return @Vector(D.lane_count, unsignedLane(D.Lane));103}104105fn unsignedLane(comptime T: type) type {106    return @Int(.unsigned, @bitSizeOf(T));107}108109test "logical operations match Highway truth tables" {110    const simd = @import("root.zig");111    const D = simd.FixedTag(u32, 4);112    const zero: D.Vector = @splat(0);113    const value: D.Vector = .{ 0, 1, 2, 3 };114    try std.testing.expect(@reduce(.And, bitAnd(D, value, value) == value));115    try std.testing.expect(@reduce(.And, bitXor(D, value, value) == zero));116    try std.testing.expect(@reduce(.And, bitOr(D, value, zero) == value));117    try std.testing.expect(allBitsZero(D, bitAnd(D, value, bitNot(D, value))));118    try std.testing.expect(allBitsOne(D, bitOr(D, value, bitNot(D, value))));119}120121test "logical operations preserve floating-point bit patterns" {122    const simd = @import("root.zig");123    const D = simd.FixedTag(f32, 4);124    const U = simd.FixedTag(u32, 4);125    const value: D.Vector = @bitCast(@as(U.Vector, .{ 0, 1, 0x8000_0000, 0x7f80_0000 }));126    const twice = bitXor(D, value, value);127    try std.testing.expect(allBitsZero(D, twice));128    const inverted: U.Vector = @bitCast(bitNot(D, value));129    try std.testing.expectEqual(@as(u32, 0xffff_ffff), inverted[0]);130    try std.testing.expectEqual(@as(u32, 0x7fff_ffff), inverted[2]);131}132133test "Highway ternary and masked logical operations match scalar bit formulas" {134    const simd = @import("root.zig");135    const D = simd.FixedTag(u8, 4);136    const a: D.Vector = .{ 0x0f, 0xf0, 0xaa, 0x55 };137    const b: D.Vector = .{ 0x33, 0x33, 0xcc, 0xcc };138    const c: D.Vector = .{ 0x55, 0xaa, 0x0f, 0xf0 };139    try std.testing.expect(@reduce(.And, xorAndNot(D, a, b, c) == (a ^ (~b & c))));140    try std.testing.expect(@reduce(.And, andXor(D, a, b, c) == (a & (b ^ c))));141    const mask: D.Mask = .{ true, false, false, true };142    try std.testing.expect(@reduce(.And, maskedOrOr(D, @splat(7), mask, a, b) ==143        @as(D.Vector, .{ 0x3f, 7, 7, 0xdd })));144    try std.testing.expect(@reduce(.And, maskedXor(D, mask, a, b) ==145        @as(D.Vector, .{ 0x3c, 0, 0, 0x99 })));146}

1pub const logical = @import("logical.zig");