1//===- llvm/IR/OptBisect/Bisect.cpp - LLVM Bisect support -----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// This file implements support for a bisecting optimizations based on a
11/// command line option.
12//
13//===----------------------------------------------------------------------===//
14
15#include "llvm/IR/OptBisect.h"
16#include "llvm/ADT/StringRef.h"
17#include "llvm/Pass.h"
18#include "llvm/Support/CommandLine.h"
19#include "llvm/Support/raw_ostream.h"
20#include <cassert>
21#include <limits>
22#include <string>
23
24using namespace llvm;
25
26static cl::opt<int> OptBisectLimit("opt-bisect-limit", cl::Hidden,
27                                   cl::init(std::numeric_limits<int>::max()),
28                                   cl::Optional,
29                                   cl::desc("Maximum optimization to perform"));
30
31OptBisect::OptBisect() : OptPassGate() {
32  BisectEnabled = OptBisectLimit != std::numeric_limits<int>::max();
33}
34
35static void printPassMessage(const StringRef &Name, int PassNum,
36                             StringRef TargetDesc, bool Running) {
37  StringRef Status = Running ? "" : "NOT ";
38  errs() << "BISECT: " << Status << "running pass "
39         << "(" << PassNum << ") " << Name << " on " << TargetDesc << "\n";
40}
41
42bool OptBisect::shouldRunPass(const Pass *P, StringRef IRDescription) {
43  assert(BisectEnabled);
44
45  return checkPass(P->getPassName(), IRDescription);
46}
47
48bool OptBisect::checkPass(const StringRef PassName,
49                          const StringRef TargetDesc) {
50  assert(BisectEnabled);
51
52  int CurBisectNum = ++LastBisectNum;
53  bool ShouldRun = (OptBisectLimit == -1 || CurBisectNum <= OptBisectLimit);
54  printPassMessage(PassName, CurBisectNum, TargetDesc, ShouldRun);
55  return ShouldRun;
56}
57