xref: /freebsd-src/contrib/llvm-project/llvm/lib/IR/OptBisect.cpp (revision 4824e7fd18a1223177218d4aec1b3c6c5c4a444e)
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(OptBisect::Disabled), cl::Optional,
26                                    cl::cb<void, int>([](int Limit) {
27                                      llvm::OptBisector->setLimit(Limit);
28                                    }),
29                                    cl::desc("Maximum optimization to perform"));
30 
31 static void printPassMessage(const StringRef &Name, int PassNum,
32                              StringRef TargetDesc, bool Running) {
33   StringRef Status = Running ? "" : "NOT ";
34   errs() << "BISECT: " << Status << "running pass "
35          << "(" << PassNum << ") " << Name << " on " << TargetDesc << "\n";
36 }
37 
38 bool OptBisect::shouldRunPass(const Pass *P, StringRef IRDescription) {
39   assert(isEnabled());
40 
41   return checkPass(P->getPassName(), IRDescription);
42 }
43 
44 bool OptBisect::checkPass(const StringRef PassName,
45                           const StringRef TargetDesc) {
46   assert(isEnabled());
47 
48   int CurBisectNum = ++LastBisectNum;
49   bool ShouldRun = (BisectLimit == -1 || CurBisectNum <= BisectLimit);
50   printPassMessage(PassName, CurBisectNum, TargetDesc, ShouldRun);
51   return ShouldRun;
52 }
53 
54 const int OptBisect::Disabled;
55 
56 ManagedStatic<OptBisect> llvm::OptBisector;
57