#pragma clang diagnostic ignored "-Wmissing-prototypes"
#pragma clang diagnostic ignored "-Wunused-variable"

#include <metal_stdlib>
#include <simd/simd.h>
#include <metal_atomic>

using namespace metal;

struct Element
{
    uint data;
    uint flag;
};

struct DataBuf
{
    Element data[1];
};

struct ControlBuf
{
    uint failures;
};

constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);

static inline __attribute__((always_inline))
uint permute_flag_ix(thread const uint& data_ix)
{
    return (data_ix * 419u) & 65535u;
}

kernel void main0(device DataBuf& data_buf [[buffer(0)]], device ControlBuf& control_buf [[buffer(1)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
{
    atomic_store_explicit((device atomic_uint*)&data_buf.data[gl_GlobalInvocationID.x].data, 1u, memory_order_relaxed);
    threadgroup_barrier(mem_flags::mem_device);
    uint param = gl_GlobalInvocationID.x;
    uint write_flag_ix = permute_flag_ix(param);
    atomic_store_explicit((device atomic_uint*)&data_buf.data[write_flag_ix].flag, 1u, memory_order_relaxed);
    uint read_ix = (gl_GlobalInvocationID.x * 4099u) & 65535u;
    uint param_1 = read_ix;
    uint read_flag_ix = permute_flag_ix(param_1);
    uint _58 = atomic_load_explicit((device atomic_uint*)&data_buf.data[read_flag_ix].flag, memory_order_relaxed);
    uint flag = _58;
    threadgroup_barrier(mem_flags::mem_device);
    uint _62 = atomic_load_explicit((device atomic_uint*)&data_buf.data[read_ix].data, memory_order_relaxed);
    uint data = _62;
    if (flag > data)
    {
        uint _73 = atomic_fetch_add_explicit((device atomic_uint*)&control_buf.failures, 1u, memory_order_relaxed);
    }
}