| /// Absolute value (magnitude) (f32) |
| /// Calculates the absolute value (magnitude) of the argument `x`, |
| /// by direct manipulation of the bit representation of `x`. |
| #[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)] |
| pub fn fabsf(x: f32) -> f32 { |
| // On wasm32 we know that LLVM's intrinsic will compile to an optimized |
| // `f32.abs` native instruction, so we can leverage this for both code size |
| // and speed. |
| llvm_intrinsically_optimized! { |
| #[cfg(target_arch = "wasm32")] { |
| return unsafe { ::core::intrinsics::fabsf32(x) } |
| } |
| } |
| f32::from_bits(x.to_bits() & 0x7fffffff) |
| } |
| |
| // PowerPC tests are failing on LLVM 13: https://github.com/rust-lang/rust/issues/88520 |
| #[cfg(not(target_arch = "powerpc64"))] |
| #[cfg(test)] |
| mod tests { |
| use super::*; |
| use core::f32::*; |
| |
| #[test] |
| fn sanity_check() { |
| assert_eq!(fabsf(-1.0), 1.0); |
| assert_eq!(fabsf(2.8), 2.8); |
| } |
| |
| /// The spec: https://en.cppreference.com/w/cpp/numeric/math/fabs |
| #[test] |
| fn spec_tests() { |
| assert!(fabsf(NAN).is_nan()); |
| for f in [0.0, -0.0].iter().copied() { |
| assert_eq!(fabsf(f), 0.0); |
| } |
| for f in [INFINITY, NEG_INFINITY].iter().copied() { |
| assert_eq!(fabsf(f), INFINITY); |
| } |
| } |
| } |