llvm/lib/Analysis/LastRunTrackingAnalysis.cpp

   1 //===- LastRunTrackingAnalysis.cpp - Avoid running redundant pass -*- C++ -*-=//
   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 // This is an analysis pass to track a set of passes that have been run, so that
  10 // we can avoid running a pass again if there is no change since the last run of
  11 // the pass.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Analysis/LastRunTrackingAnalysis.h"
  16 #include "llvm/ADT/Statistic.h"
  17 #include "llvm/Support/CommandLine.h"
  18
  19 using namespace llvm;
  20
  21 #define DEBUG_TYPE "last-run-tracking"
  22 STATISTIC(NumSkippedPasses, "Number of skipped passes");
  23 STATISTIC(NumLRTQueries, "Number of LastRunTracking queries");
  24
  25 static cl::opt<bool>
  26     DisableLastRunTracking("disable-last-run-tracking", cl::Hidden,
  27                            cl::desc("Disable last run tracking"),
  28                            cl::init(false));
  29
  30 bool LastRunTrackingInfo::shouldSkipImpl(PassID ID, OptionPtr Ptr) const {
  31   if (DisableLastRunTracking)
  32     return false;
  33   ++NumLRTQueries;
  34   auto Iter = TrackedPasses.find(ID);
  35   if (Iter == TrackedPasses.end())
  36     return false;
  37   if (!Iter->second || Iter->second(Ptr)) {
  38     ++NumSkippedPasses;
  39     return true;
  40   }
  41   return false;
  42 }
  43
  44 void LastRunTrackingInfo::updateImpl(PassID ID, bool Changed,
  45                                      CompatibilityCheckFn CheckFn) {
  46   if (Changed)
  47     TrackedPasses.clear();
  48   TrackedPasses[ID] = std::move(CheckFn);
  49 }
  50
  51 AnalysisKey LastRunTrackingAnalysis::Key;