zig/std/math/isnormal.zig
Andrew Kelley c9fc8bd802 workaround for llvm bug
See #393 for details
2017-06-19 14:36:33 -04:00

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Zig

const math = @import("index.zig");
const assert = @import("../debug.zig").assert;
pub fn isNormal(x: var) -> bool {
const T = @typeOf(x);
switch (T) {
f32 => {
const bits = @bitCast(u32, x);
(bits + 0x00800000) & 0x7FFFFFFF >= 0x01000000
},
f64 => {
const bits = @bitCast(u64, x);
(bits + (1 << 52)) & (@maxValue(u64) >> 1) >= (1 << 53)
},
else => {
@compileError("isNormal not implemented for " ++ @typeName(T));
},
}
}
test "math.isNormal" {
assert(!isNormal(math.nan(f32)));
assert(!isNormal(math.nan(f64)));
assert(isNormal(f32(1.0)));
assert(isNormal(f64(1.0)));
}