llvm/lib/IR/OptBisect.cpp

   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;