1#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
2pub fn rintf(x: f32) -> f32 {
3 let one_over_e = 1.0 / f32::EPSILON;
4 let as_u32: u32 = x.to_bits();
5 let exponent: u32 = as_u32 >> 23 & 0xff;
6 let is_positive = (as_u32 >> 31) == 0;
7 if exponent >= 0x7f + 23 {
8 x
9 } else {
10 let ans = if is_positive {
11 #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]
12 let x = force_eval!(x);
13 let xplusoneovere = x + one_over_e;
14 #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]
15 let xplusoneovere = force_eval!(xplusoneovere);
16 xplusoneovere - one_over_e
17 } else {
18 #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]
19 let x = force_eval!(x);
20 let xminusoneovere = x - one_over_e;
21 #[cfg(all(target_arch = "x86", not(target_feature = "sse2")))]
22 let xminusoneovere = force_eval!(xminusoneovere);
23 xminusoneovere + one_over_e
24 };
25
26 if ans == 0.0 { if is_positive { 0.0 } else { -0.0 } } else { ans }
27 }
28}
29
30// PowerPC tests are failing on LLVM 13: https://github.com/rust-lang/rust/issues/88520
31#[cfg(not(target_arch = "powerpc64"))]
32#[cfg(test)]
33mod tests {
34 use super::rintf;
35
36 #[test]
37 fn negative_zero() {
38 assert_eq!(rintf(-0.0_f32).to_bits(), (-0.0_f32).to_bits());
39 }
40
41 #[test]
42 fn sanity_check() {
43 assert_eq!(rintf(-1.0), -1.0);
44 assert_eq!(rintf(2.8), 3.0);
45 assert_eq!(rintf(-0.5), -0.0);
46 assert_eq!(rintf(0.5), 0.0);
47 assert_eq!(rintf(-1.5), -2.0);
48 assert_eq!(rintf(1.5), 2.0);
49 }
50}
51