34 lines
887 B
Zig
34 lines
887 B
Zig
const std = @import("../index.zig");
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const math = std.math;
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const assert = std.debug.assert;
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pub fn isNan(x: var) bool {
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const T = @typeOf(x);
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switch (T) {
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f32 => {
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const bits = @bitCast(u32, x);
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return bits & 0x7FFFFFFF > 0x7F800000;
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},
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f64 => {
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const bits = @bitCast(u64, x);
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return (bits & (@maxValue(u64) >> 1)) > (u64(0x7FF) << 52);
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},
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else => {
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@compileError("isNan not implemented for " ++ @typeName(T));
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},
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}
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}
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// Note: A signalling nan is identical to a standard right now by may have a different bit
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// representation in the future when required.
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pub fn isSignalNan(x: var) bool {
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return isNan(x);
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}
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test "math.isNan" {
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assert(isNan(math.nan(f32)));
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assert(isNan(math.nan(f64)));
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assert(!isNan(f32(1.0)));
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assert(!isNan(f64(1.0)));
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}
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