//! Implements vertical (lane-wise) floating-point `rsqrte`. macro_rules! impl_math_float_rsqrte { ([$elem_ty:ident; $elem_count:expr]: $id:ident | $test_tt:tt) => { impl $id { /// Reciprocal square-root estimate: `~= 1. / self.sqrt()`. /// /// FIXME: The precision of the estimate is currently unspecified. #[inline] pub fn rsqrte(self) -> Self { unsafe { use crate::llvm::simd_fsqrt; $id::splat(1.) / Simd(simd_fsqrt(self.0)) } } } test_if!{ $test_tt: paste::item! { pub mod [<$id _math_rsqrte>] { use super::*; #[cfg_attr(not(target_arch = "wasm32"), test)] #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)] fn rsqrte() { use crate::$elem_ty::consts::SQRT_2; let tol = $id::splat(2.4e-4 as $elem_ty); let o = $id::splat(1 as $elem_ty); let error = (o - o.rsqrte()).abs(); assert!(error.le(tol).all()); let t = $id::splat(2 as $elem_ty); let e = 1. / SQRT_2; let error = (e - t.rsqrte()).abs(); assert!(error.le(tol).all()); } } } } }; }