40 lines
1.0 KiB
Zig
40 lines
1.0 KiB
Zig
const std = @import("../index.zig");
|
|
const math = std.math;
|
|
const assert = std.debug.assert;
|
|
|
|
pub fn isNan(x: var) bool {
|
|
const T = @typeOf(x);
|
|
switch (T) {
|
|
f16 => {
|
|
const bits = @bitCast(u16, x);
|
|
return (bits & 0x7fff) > 0x7c00;
|
|
},
|
|
f32 => {
|
|
const bits = @bitCast(u32, x);
|
|
return bits & 0x7FFFFFFF > 0x7F800000;
|
|
},
|
|
f64 => {
|
|
const bits = @bitCast(u64, x);
|
|
return (bits & (@maxValue(u64) >> 1)) > (u64(0x7FF) << 52);
|
|
},
|
|
else => {
|
|
@compileError("isNan not implemented for " ++ @typeName(T));
|
|
},
|
|
}
|
|
}
|
|
|
|
// Note: A signalling nan is identical to a standard right now by may have a different bit
|
|
// representation in the future when required.
|
|
pub fn isSignalNan(x: var) bool {
|
|
return isNan(x);
|
|
}
|
|
|
|
test "math.isNan" {
|
|
assert(isNan(math.nan(f16)));
|
|
assert(isNan(math.nan(f32)));
|
|
assert(isNan(math.nan(f64)));
|
|
assert(!isNan(f16(1.0)));
|
|
assert(!isNan(f32(1.0)));
|
|
assert(!isNan(f64(1.0)));
|
|
}
|