// SPDX-License-Identifier: MIT // Copyright (c) 2015-2020 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.zig"); const math = std.math; const expect = std.testing.expect; const maxInt = std.math.maxInt; // Returns whether x has a normalized representation (i.e. integer part of mantissa is 1). pub fn isNormal(x: anytype) bool { const T = @TypeOf(x); switch (T) { f16 => { const bits = @bitCast(u16, x); return (bits + 1024) & 0x7FFF >= 2048; }, f32 => { const bits = @bitCast(u32, x); return (bits + 0x00800000) & 0x7FFFFFFF >= 0x01000000; }, f64 => { const bits = @bitCast(u64, x); return (bits + (1 << 52)) & (maxInt(u64) >> 1) >= (1 << 53); }, else => { @compileError("isNormal not implemented for " ++ @typeName(T)); }, } } test "math.isNormal" { expect(!isNormal(math.nan(f16))); expect(!isNormal(math.nan(f32))); expect(!isNormal(math.nan(f64))); expect(!isNormal(@as(f16, 0))); expect(!isNormal(@as(f32, 0))); expect(!isNormal(@as(f64, 0))); expect(isNormal(@as(f16, 1.0))); expect(isNormal(@as(f32, 1.0))); expect(isNormal(@as(f64, 1.0))); }