//===- MathExtras.h - Math functions relevant to MLIR -----------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file contains math functions relevant to MLIR.

//

//===----------------------------------------------------------------------===//

#ifndef MLIR_SUPPORT_MATHEXTRAS_H_

#define MLIR_SUPPORT_MATHEXTRAS_H_

#include "mlir/Support/LLVM.h"

#include "llvm/ADT/APInt.h"

namespace mlir {

/// Returns the result of MLIR's ceildiv operation on constants. The RHS is

/// expected to be positive.

inline int64_t ceilDiv(int64_t lhs, int64_t rhs) {

  assert(rhs >= 1);

  // C/C++'s integer division rounds towards 0.

  return lhs % rhs > 0 ? lhs / rhs + 1 : lhs / rhs;

}

/// Returns the result of MLIR's floordiv operation on constants. The RHS is

/// expected to be positive.

inline int64_t floorDiv(int64_t lhs, int64_t rhs) {

  assert(rhs >= 1);

  // C/C++'s integer division rounds towards 0.

  return lhs % rhs < 0 ? lhs / rhs - 1 : lhs / rhs;

}

/// Returns MLIR's mod operation on constants. MLIR's mod operation yields the

/// remainder of the Euclidean division of 'lhs' by 'rhs', and is therefore not

/// C's % operator.  The RHS is always expected to be positive, and the result

/// is always non-negative.

inline int64_t mod(int64_t lhs, int64_t rhs) {

  assert(rhs >= 1);

  return lhs % rhs < 0 ? lhs % rhs + rhs : lhs % rhs;

}

/// Returns the least common multiple of 'a' and 'b'.

inline int64_t lcm(int64_t a, int64_t b) {

  uint64_t x = std::abs(a);

  uint64_t y = std::abs(b);

  int64_t lcm = (x * y) / llvm::GreatestCommonDivisor64(x, y);

  assert((lcm >= a && lcm >= b) && "LCM overflow");

  return lcm;

}

} // end namespace mlir

#endif // MLIR_SUPPORT_MATHEXTRAS_H_