//! Vertical (lane-wise) vector-vector shifts operations.

macro_rules! impl_ops_vector_shifts {
    ([$elem_ty:ident; $elem_count:expr]: $id:ident | $test_tt:tt) => {
        impl crate::ops::Shl<$id> for $id {
            type Output = Self;
            #[inline]
            fn shl(self, other: Self) -> Self {
                use crate::llvm::simd_shl;
                unsafe { Simd(simd_shl(self.0, other.0)) }
            }
        }
        impl crate::ops::Shr<$id> for $id {
            type Output = Self;
            #[inline]
            fn shr(self, other: Self) -> Self {
                use crate::llvm::simd_shr;
                unsafe { Simd(simd_shr(self.0, other.0)) }
            }
        }
        impl crate::ops::ShlAssign<$id> for $id {
            #[inline]
            fn shl_assign(&mut self, other: Self) {
                *self = *self << other;
            }
        }
        impl crate::ops::ShrAssign<$id> for $id {
            #[inline]
            fn shr_assign(&mut self, other: Self) {
                *self = *self >> other;
            }
        }
        test_if!{
            $test_tt:
            paste::item! {
                pub mod [<$id _ops_vector_shifts>] {
                    use super::*;
                    #[cfg_attr(not(target_arch = "wasm32"), test)] #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
                    #[cfg_attr(any(target_arch = "s390x", target_arch = "sparc64"),
                               allow(unreachable_code,
                                     unused_variables,
                                     unused_mut)
                    )]
                    // ^^^ FIXME: https://github.com/rust-lang/rust/issues/55344
                    fn ops_vector_shifts() {
                        let z = $id::splat(0 as $elem_ty);
                        let o = $id::splat(1 as $elem_ty);
                        let t = $id::splat(2 as $elem_ty);
                        let f = $id::splat(4 as $elem_ty);

                        let max =$id::splat(
                            (mem::size_of::<$elem_ty>() * 8 - 1) as $elem_ty
                        );

                        // shr
                        assert_eq!(z >> z, z);
                        assert_eq!(z >> o, z);
                        assert_eq!(z >> t, z);
                        assert_eq!(z >> t, z);

                        #[cfg(any(target_arch = "s390x", target_arch = "sparc64"))] {
                            // FIXME: rust produces bad codegen for shifts:
                            // https://github.com/rust-lang-nursery/packed_simd/issues/13
                            return;
                        }

                        assert_eq!(o >> z, o);
                        assert_eq!(t >> z, t);
                        assert_eq!(f >> z, f);
                        assert_eq!(f >> max, z);

                        assert_eq!(o >> o, z);
                        assert_eq!(t >> o, o);
                        assert_eq!(t >> t, z);
                        assert_eq!(f >> o, t);
                        assert_eq!(f >> t, o);
                        assert_eq!(f >> max, z);

                        // shl
                        assert_eq!(z << z, z);
                        assert_eq!(o << z, o);
                        assert_eq!(t << z, t);
                        assert_eq!(f << z, f);
                        assert_eq!(f << max, z);

                        assert_eq!(o << o, t);
                        assert_eq!(o << t, f);
                        assert_eq!(t << o, f);

                        {
                            // shr_assign
                            let mut v = o;
                            v >>= o;
                            assert_eq!(v, z);
                        }
                        {
                            // shl_assign
                            let mut v = o;
                            v <<= o;
                            assert_eq!(v, t);
                        }
                    }
                }
            }
        }
    };
}