35 lines
1.1 KiB
Zig
35 lines
1.1 KiB
Zig
const std = @import("../std.zig");
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const math = std.math;
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const expect = std.testing.expect;
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/// Returns whether x is a finite value.
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pub fn isFinite(x: anytype) bool {
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const T = @TypeOf(x);
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const TBits = std.meta.Int(.unsigned, @typeInfo(T).float.bits);
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const remove_sign = ~@as(TBits, 0) >> 1;
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return @as(TBits, @bitCast(x)) & remove_sign < @as(TBits, @bitCast(math.inf(T)));
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}
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test isFinite {
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inline for ([_]type{ f16, f32, f64, f80, f128 }) |T| {
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// normals
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try expect(isFinite(@as(T, 1.0)));
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try expect(isFinite(-@as(T, 1.0)));
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// zero & subnormals
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try expect(isFinite(@as(T, 0.0)));
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try expect(isFinite(@as(T, -0.0)));
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try expect(isFinite(math.floatTrueMin(T)));
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// other float limits
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try expect(isFinite(math.floatMin(T)));
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try expect(isFinite(math.floatMax(T)));
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// inf & nan
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try expect(!isFinite(math.inf(T)));
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try expect(!isFinite(-math.inf(T)));
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try expect(!isFinite(math.nan(T)));
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try expect(!isFinite(-math.nan(T)));
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}
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}
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