fabsf.rs - source
Description: Source of the Rust file `/Users/erlendbasso/.cargo/registry/src/github.com-1ecc6299db9ec823/libm-0.2.6/src/math/fabsf.rs`.
Keywords: rust, rustlang, rust-lang

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    /// 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);
            }
        }
    }