llvm/llvm/lib/Support/OptimizedStructLayout.cpp

//===--- OptimizedStructLayout.cpp - Optimal data layout algorithm ----------------===//
//
// 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 implements the performOptimizedStructLayout interface.
//
//===----------------------------------------------------------------------===//

#include "llvm/Support/OptimizedStructLayout.h"
#include <optional>

usingnamespacellvm;

Field;

#ifndef NDEBUG
static void checkValidLayout(ArrayRef<Field> Fields, uint64_t Size,
                             Align MaxAlign) {
  uint64_t LastEnd = 0;
  Align ComputedMaxAlign;
  for (auto &Field : Fields) {
    assert(Field.hasFixedOffset() &&
           "didn't assign a fixed offset to field");
    assert(isAligned(Field.Alignment, Field.Offset) &&
           "didn't assign a correctly-aligned offset to field");
    assert(Field.Offset >= LastEnd &&
           "didn't assign offsets in ascending order");
    LastEnd = Field.getEndOffset();
    assert(Field.Alignment <= MaxAlign &&
           "didn't compute MaxAlign correctly");
    ComputedMaxAlign = std::max(Field.Alignment, MaxAlign);
  }
  assert(LastEnd == Size && "didn't compute LastEnd correctly");
  assert(ComputedMaxAlign == MaxAlign && "didn't compute MaxAlign correctly");
}
#endif

std::pair<uint64_t, Align>
llvm::performOptimizedStructLayout(MutableArrayRef<Field> Fields) { … }