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 #include <limits>
21
22 using namespace llvm;
23
24 static cl::opt<int> OptBisectLimit("opt-bisect-limit", cl::Hidden,
25 cl::init(std::numeric_limits<int>::max()),
26 cl::Optional,
27 cl::desc("Maximum optimization to perform"));
28
OptBisect()29 OptBisect::OptBisect() : OptPassGate() {
30 BisectEnabled = OptBisectLimit != std::numeric_limits<int>::max();
31 }
32
printPassMessage(const StringRef & Name,int PassNum,StringRef TargetDesc,bool Running)33 static void printPassMessage(const StringRef &Name, int PassNum,
34 StringRef TargetDesc, bool Running) {
35 StringRef Status = Running ? "" : "NOT ";
36 errs() << "BISECT: " << Status << "running pass "
37 << "(" << PassNum << ") " << Name << " on " << TargetDesc << "\n";
38 }
39
shouldRunPass(const Pass * P,StringRef IRDescription)40 bool OptBisect::shouldRunPass(const Pass *P, StringRef IRDescription) {
41 assert(BisectEnabled);
42
43 return checkPass(P->getPassName(), IRDescription);
44 }
45
checkPass(const StringRef PassName,const StringRef TargetDesc)46 bool OptBisect::checkPass(const StringRef PassName,
47 const StringRef TargetDesc) {
48 assert(BisectEnabled);
49
50 int CurBisectNum = ++LastBisectNum;
51 bool ShouldRun = (OptBisectLimit == -1 || CurBisectNum <= OptBisectLimit);
52 printPassMessage(PassName, CurBisectNum, TargetDesc, ShouldRun);
53 return ShouldRun;
54 }
55
56 ManagedStatic<OptBisect> llvm::OptBisector;
57