mirror of
https://codeberg.org/ziglang/zig.git
synced 2025-12-06 05:44:20 +00:00
6bc6e47b15
Rather than lowering float negation as `0.0 - x`. * Add AIR instruction for float negation. * Add compiler-rt functions for f128, f80 negation closes #11853
23 lines
766 B
Zig
23 lines
766 B
Zig
const std = @import("../std.zig");
|
|
const math = std.math;
|
|
const expect = std.testing.expect;
|
|
|
|
/// Returns whether x is negative or negative 0.
|
|
pub fn signbit(x: anytype) bool {
|
|
const T = @TypeOf(x);
|
|
const TBits = std.meta.Int(.unsigned, @typeInfo(T).Float.bits);
|
|
return @bitCast(TBits, x) >> (@bitSizeOf(T) - 1) != 0;
|
|
}
|
|
|
|
test "math.signbit" {
|
|
inline for ([_]type{ f16, f32, f64, f80, f128 }) |T| {
|
|
try expect(!signbit(@as(T, 0.0)));
|
|
try expect(!signbit(@as(T, 1.0)));
|
|
try expect(signbit(@as(T, -2.0)));
|
|
try expect(signbit(@as(T, -0.0)));
|
|
try expect(!signbit(math.inf(T)));
|
|
try expect(signbit(-math.inf(T)));
|
|
try expect(!signbit(math.nan(T)));
|
|
try expect(signbit(-math.nan(T)));
|
|
}
|
|
}
|