//===-------- AADumper.cpp - Compare all values in Function with AA -------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This pass collects all values in a function and applies alias analysis to
// them. The purpose of this is to enable unit tests for SIL Alias Analysis
// implementations independent of any other passes.
//
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "sil-aa-evaluator"
#include "swift/SILPasses/Passes.h"
#include "swift/SIL/SILArgument.h"
#include "swift/SIL/SILFunction.h"
#include "swift/SIL/SILValue.h"
#include "swift/SILAnalysis/AliasAnalysis.h"
#include "swift/SILAnalysis/Analysis.h"
#include "swift/SILPasses/Transforms.h"
#include "llvm/Support/Debug.h"

using namespace swift;

//===----------------------------------------------------------------------===//
//                               Value Gatherer
//===----------------------------------------------------------------------===//

// Return a list of all instruction values in Fn. Returns true if we have at
// least two values to compare.
static bool gatherValues(SILFunction &Fn, std::vector<SILValue> &Values) {
  for (auto &BB : Fn) {
    for (auto *Arg : BB.getBBArgs())
      Values.push_back(SILValue(Arg));
    for (auto &II : BB)
      for (unsigned i = 0, e = II.getNumTypes(); i != e; ++i)
        Values.push_back(SILValue(&II, i));
  }
  return Values.size() > 1;
}

//===----------------------------------------------------------------------===//
//                              Top Level Driver
//===----------------------------------------------------------------------===//

namespace {

class SILAADumper : public SILFunctionTransform {

  void run() override {
    SILFunction &Fn = *getFunction();
    llvm::outs() << "@" << Fn.getName() << "\n";
    // Gather up all Values in Fn.
    std::vector<SILValue> Values;
    if (!gatherValues(Fn, Values))
      return;

    AliasAnalysis *AA = PM->getAnalysis<AliasAnalysis>();

    // A cache
    llvm::DenseMap<uint64_t, AliasAnalysis::AliasResult> Results;

    // Emit the N^2 alias evaluation of the values.
    unsigned PairCount = 0;
    for (unsigned i1 = 0, e1 = Values.size(); i1 != e1; ++i1) {
      for (unsigned i2 = 0, e2 = Values.size(); i2 != e2; ++i2) {
        auto V1 = Values[i1];
        auto V2 = Values[i2];

        auto Result =
            AA->alias(V1, V2, findTypedAccessType(V1), findTypedAccessType(V2));

        // Results should always be the same. But if they are different print it
        // out so we find the error. This should make our test results less
        // verbose.
        uint64_t Key = uint64_t(i1) | (uint64_t(i2) << 32);
        uint64_t OpKey = uint64_t(i2) | (uint64_t(i1) << 32);
        auto R = Results.find(OpKey);
        if (R != Results.end() && R->second == Result)
          continue;

        Results[Key] = Result;
        llvm::outs() << "PAIR #" << PairCount++ << ".\n" << V1 << V2 << Result
                     << "\n";
      }
    }

    llvm::outs() << "\n";
  }

  StringRef getName() override { return "AA Dumper"; }
};

} // end anonymous namespace

SILTransform *swift::createAADumper() { return new SILAADumper(); }