diff options
Diffstat (limited to 'third_party/rust/packed_simd/src/api/math/float/rsqrte.rs')
-rw-r--r-- | third_party/rust/packed_simd/src/api/math/float/rsqrte.rs | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/third_party/rust/packed_simd/src/api/math/float/rsqrte.rs b/third_party/rust/packed_simd/src/api/math/float/rsqrte.rs new file mode 100644 index 0000000000..c77977f7b1 --- /dev/null +++ b/third_party/rust/packed_simd/src/api/math/float/rsqrte.rs @@ -0,0 +1,40 @@ +//! 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()); + } + } + } + } + }; +} |