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
  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 cl::opt<bool> OptBisectVerbose(
  36     "opt-bisect-verbose",
  37     cl::desc("Show verbose output when opt-bisect-limit is set"), cl::Hidden,
  38     cl::init(true), cl::Optional);
  39
  40 static void printPassMessage(const StringRef &Name, int PassNum,
  41                              StringRef TargetDesc, bool Running) {
  42   StringRef Status = Running ? "" : "NOT ";
  43   errs() << "BISECT: " << Status << "running pass "
  44          << "(" << PassNum << ") " << Name << " on " << TargetDesc << "\n";
  45 }
  46
  47 bool OptBisect::shouldRunPass(const StringRef PassName,
  48                               StringRef IRDescription) {
  49   assert(isEnabled());
  50
  51   int CurBisectNum = ++LastBisectNum;
  52   bool ShouldRun = (BisectLimit == -1 || CurBisectNum <= BisectLimit);
  53   if (OptBisectVerbose)
  54     printPassMessage(PassName, CurBisectNum, IRDescription, ShouldRun);
  55   return ShouldRun;
  56 }
  57
  58 const int OptBisect::Disabled;
  59
  60 OptPassGate &llvm::getGlobalPassGate() { return getOptBisector(); }