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/Pass.h"
17 #include "llvm/Support/CommandLine.h"
18 #include "llvm/Support/raw_ostream.h"
19 #include <cassert>
20 
21 using namespace llvm;
22 
23 static OptBisect &getOptBisector() {
24   static OptBisect OptBisector;
25   return OptBisector;
26 }
27 
28 static cl::opt<int> OptBisectLimit("opt-bisect-limit", cl::Hidden,
29                                    cl::init(OptBisect::Disabled), cl::Optional,
30                                    cl::cb<void, int>([](int Limit) {
31                                      getOptBisector().setLimit(Limit);
32                                    }),
33                                    cl::desc("Maximum optimization to perform"));
34 
35 static 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 
42 bool OptBisect::shouldRunPass(const StringRef PassName,
43                               StringRef IRDescription) {
44   assert(isEnabled());
45 
46   int CurBisectNum = ++LastBisectNum;
47   bool ShouldRun = (BisectLimit == -1 || CurBisectNum <= BisectLimit);
48   printPassMessage(PassName, CurBisectNum, IRDescription, ShouldRun);
49   return ShouldRun;
50 }
51 
52 const int OptBisect::Disabled;
53 
54 OptPassGate &llvm::getGlobalPassGate() { return getOptBisector(); }
55