mirror of
https://github.com/ziglang/zig.git
synced 2025-12-24 23:23:07 +00:00
4c16f9a3c3
This covers the majority of the functions as covered by the C99 specification for a math library. Code is adapted primarily from musl libc, with the pow and standard trigonometric functions adapted from the Go stdlib. Changes: - Remove assert expose in index and import as needed. - Add float log function and merge with existing base 2 integer implementation. See https://github.com/tiehuis/zig-fmath. See #374.
48 lines
1.3 KiB
Zig
48 lines
1.3 KiB
Zig
const math = @import("index.zig");
|
|
const assert = @import("../debug.zig").assert;
|
|
|
|
pub fn copysign(comptime T: type, x: T, y: T) -> T {
|
|
switch (T) {
|
|
f32 => @inlineCall(copysign32, x, y),
|
|
f64 => @inlineCall(copysign64, x, y),
|
|
else => @compileError("copysign not implemented for " ++ @typeName(T)),
|
|
}
|
|
}
|
|
|
|
fn copysign32(x: f32, y: f32) -> f32 {
|
|
const ux = @bitCast(u32, x);
|
|
const uy = @bitCast(u32, y);
|
|
|
|
const h1 = ux & (@maxValue(u32) / 2);
|
|
const h2 = uy & (u32(1) << 31);
|
|
@bitCast(f32, h1 | h2)
|
|
}
|
|
|
|
fn copysign64(x: f64, y: f64) -> f64 {
|
|
const ux = @bitCast(u64, x);
|
|
const uy = @bitCast(u64, y);
|
|
|
|
const h1 = ux & (@maxValue(u64) / 2);
|
|
const h2 = uy & (u64(1) << 63);
|
|
@bitCast(f64, h1 | h2)
|
|
}
|
|
|
|
test "copysign" {
|
|
assert(copysign(f32, 1.0, 1.0) == copysign32(1.0, 1.0));
|
|
assert(copysign(f64, 1.0, 1.0) == copysign64(1.0, 1.0));
|
|
}
|
|
|
|
test "copysign32" {
|
|
assert(copysign32(5.0, 1.0) == 5.0);
|
|
assert(copysign32(5.0, -1.0) == -5.0);
|
|
assert(copysign32(-5.0, -1.0) == -5.0);
|
|
assert(copysign32(-5.0, 1.0) == 5.0);
|
|
}
|
|
|
|
test "copysign64" {
|
|
assert(copysign64(5.0, 1.0) == 5.0);
|
|
assert(copysign64(5.0, -1.0) == -5.0);
|
|
assert(copysign64(-5.0, -1.0) == -5.0);
|
|
assert(copysign64(-5.0, 1.0) == 5.0);
|
|
}
|