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    //! Implements portable arithmetic vector reductions.
    #![allow(unused)]

    macro_rules! impl_arithmetic_reductions {
        ($id:ident, $elem_ty:ident) => {
            impl $id {
                /// Horizontal sum of the vector elements.
                ///
                /// The intrinsic performs a tree-reduction of the vector elements.
                /// That is, for an 8 element vector:
                ///
                /// > ((x0 + x1) + (x2 + x3)) + ((x4 + x5) + (x6 + x7))
                ///
                /// # Integer vectors
                ///
                /// If an operation overflows it returns the mathematical result
                /// modulo `2^n` where `n` is the number of times it overflows.
                ///
                /// # Floating-point vectors
                ///
                /// If one of the vector element is `NaN` the reduction returns
                /// `NaN`.
                #[cfg(not(target_arch = "aarch64"))]
                #[inline]
                pub fn wrapping_sum(self) -> $elem_ty {
                    use coresimd::simd_llvm::simd_reduce_add_ordered;
                    unsafe { simd_reduce_add_ordered(self, 0 as $elem_ty) }
                }
                /// Horizontal sum of the vector elements.
                ///
                /// The intrinsic performs a tree-reduction of the vector elements.
                /// That is, for an 8 element vector:
                ///
                /// > ((x0 + x1) + (x2 + x3)) + ((x4 + x5) + (x6 + x7))
                ///
                /// # Integer vectors
                ///
                /// If an operation overflows it returns the mathematical result
                /// modulo `2^n` where `n` is the number of times it overflows.
                ///
                /// # Floating-point vectors
                ///
                /// If one of the vector element is `NaN` the reduction returns
                /// `NaN`.
                #[cfg(target_arch = "aarch64")]
                #[inline]
                pub fn wrapping_sum(self) -> $elem_ty {
                    // FIXME: broken on AArch64
                    // https://bugs.llvm.org/show_bug.cgi?id=36796
                    use super::codegen::wrapping::Wrapping;
                    let mut x = self.extract(0) as $elem_ty;
                    for i in 1..$id::lanes() {
                        x = Wrapping::add(x, self.extract(i) as $elem_ty);
                    }
                    x
                }

                /// Horizontal product of the vector elements.
                ///
                /// The intrinsic performs a tree-reduction of the vector elements.
                /// That is, for an 8 element vector:
                ///
                /// > ((x0 * x1) * (x2 * x3)) * ((x4 * x5) * (x6 * x7))
                ///
                /// # Integer vectors
                ///
                /// If an operation overflows it returns the mathematical result
                /// modulo `2^n` where `n` is the number of times it overflows.
                ///
                /// # Floating-point vectors
                ///
                /// If one of the vector element is `NaN` the reduction returns
                /// `NaN`.
                #[cfg(not(target_arch = "aarch64"))]
                #[inline]
                pub fn wrapping_product(self) -> $elem_ty {
                    use coresimd::simd_llvm::simd_reduce_mul_ordered;
                    unsafe { simd_reduce_mul_ordered(self, 1 as $elem_ty) }
                }
                /// Horizontal product of the vector elements.
                ///
                /// The intrinsic performs a tree-reduction of the vector elements.
                /// That is, for an 8 element vector:
                ///
                /// > ((x0 * x1) * (x2 * x3)) * ((x4 * x5) * (x6 * x7))
                ///
                /// # Integer vectors
                ///
                /// If an operation overflows it returns the mathematical result
                /// modulo `2^n` where `n` is the number of times it overflows.
                ///
                /// # Floating-point vectors
                ///
                /// If one of the vector element is `NaN` the reduction returns
                /// `NaN`.
                #[cfg(target_arch = "aarch64")]
                #[inline]
                pub fn wrapping_product(self) -> $elem_ty {
                    // FIXME: broken on AArch64
                    // https://bugs.llvm.org/show_bug.cgi?id=36796
                    use super::codegen::wrapping::Wrapping;
                    let mut x = self.extract(0) as $elem_ty;
                    for i in 1..$id::lanes() {
                        x = Wrapping::mul(x, self.extract(i) as $elem_ty);
                    }
                    x
                }
            }
        };
    }

    #[cfg(test)]
    macro_rules! test_arithmetic_reductions {
        ($id:ident, $elem_ty:ident) => {
            fn alternating(x: usize) -> ::coresimd::simd::$id {
                use coresimd::simd::$id;
                let mut v = $id::splat(1 as $elem_ty);
                for i in 0..$id::lanes() {
                    if i % x == 0 {
                        v = v.replace(i, 2 as $elem_ty);
                    }
                }
                v
            }

            #[test]
            fn wrapping_sum() {
                use coresimd::simd::$id;
                let v = $id::splat(0 as $elem_ty);
                assert_eq!(v.wrapping_sum(), 0 as $elem_ty);
                let v = $id::splat(1 as $elem_ty);
                assert_eq!(v.wrapping_sum(), $id::lanes() as $elem_ty);
                let v = alternating(2);
                assert_eq!(
                    v.wrapping_sum(),
                    ($id::lanes() / 2 + $id::lanes()) as $elem_ty
                );
            }
            #[test]
            fn wrapping_product() {
                use coresimd::simd::$id;
                let v = $id::splat(0 as $elem_ty);
                assert_eq!(v.wrapping_product(), 0 as $elem_ty);
                let v = $id::splat(1 as $elem_ty);
                assert_eq!(v.wrapping_product(), 1 as $elem_ty);
                let f = match $id::lanes() {
                    64 => 16,
                    32 => 8,
                    16 => 4,
                    _ => 2,
                };
                let v = alternating(f);
                assert_eq!(
                    v.wrapping_product(),
                    (2_usize.pow(($id::lanes() / f) as u32) as $elem_ty)
                );
            }
        };
    }

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