// This file is part of the SV-Benchmarks collection of verification tasks:
// https://gitlab.com/sosy-lab/benchmarking/sv-benchmarks
//
// SPDX-FileCopyrightText: 2012-2021 The SV-Benchmarks Community
// SPDX-FileCopyrightText: 2012 FBK-ES <https://es.fbk.eu/>
//
// SPDX-License-Identifier: Apache-2.0

extern void abort(void);
#include <assert.h>
void reach_error() { assert(0); }

extern unsigned short __VERIFIER_nondet_ushort(void);
void __VERIFIER_assert(int cond) {
  if (!(cond)) {
    ERROR: {reach_error();abort();}
  }
  return;
}
/* https://graphics.stanford.edu/~seander/bithacks.html#InterleaveTableObvious */
#include <assert.h>

int main()
{
    /* Interleave bits of x and y, so that all of the */
    /* bits of x are in the even positions and y in the odd; */
    unsigned short x = __VERIFIER_nondet_ushort();
    unsigned short y = __VERIFIER_nondet_ushort();

    unsigned int xx;
    unsigned int yy;
    unsigned int zz;
    
    unsigned int z = 0; /* z gets the resulting Morton Number. */
    unsigned int i = 0;

    while (i < sizeof(x) * 8) {
        z |= ((x & (1U << i)) << i) | ((y & (1U << i)) << (i + 1));
        i += 1U;
    }

    xx = x;
    yy = y;

    xx = (xx | (xx << 8u)) & 16711935U; /* 0x00FF00FF */
    xx = (xx | (xx << 4u)) & 252645135U; /* 0x0F0F0F0F */
    xx = (xx | (xx << 2u)) & 858993459U; /* 0x33333333 */
    xx = (xx | (xx << 1u)) & 1431655765U; /* 0x55555555 */
        
    yy = (yy | (yy << 8u)) & 16711935U; /* 0x00FF00FF */
    yy = (yy | (yy << 4u)) & 252645135U; /* 0x0F0F0F0F */
    yy = (yy | (yy << 2u)) & 858993459U; /* 0x33333333 */
    yy = (yy | (yy << 1u)) & 1431655765U; /* 0x55555555 */
    
    zz = xx | (yy << 1U);

    __VERIFIER_assert(z == zz);
}