tools/llvm-reduce/deltas/ReduceInstructions.cpp

   1 //===- ReduceArguments.cpp - Specialized Delta Pass -----------------------===//
   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 file implements a function which calls the Generic Delta pass in order
  10 // to reduce uninteresting Arguments from defined functions.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "ReduceInstructions.h"
  15
  16 using namespace llvm;
  17
  18 /// Removes out-of-chunk arguments from functions, and modifies their calls
  19 /// accordingly. It also removes allocations of out-of-chunk arguments.
  20 static void extractInstrFromModule(std::vector<Chunk> ChunksToKeep,
  21                                    Module *Program) {
  22   int I = 0, InstCount = 0;
  23   std::set<Instruction *> InstToKeep;
  24
  25   for (auto &F : *Program)
  26     for (auto &BB : F)
  27       for (auto &Inst : BB)
  28         if (I < (int)ChunksToKeep.size()) {
  29           if (ChunksToKeep[I].contains(++InstCount))
  30             InstToKeep.insert(&Inst);
  31           if (ChunksToKeep[I].end == InstCount)
  32             ++I;
  33         }
  34
  35   std::vector<Instruction *> InstToDelete;
  36   for (auto &F : *Program)
  37     for (auto &BB : F)
  38       for (auto &Inst : BB)
  39         if (!InstToKeep.count(&Inst)) {
  40           Inst.replaceAllUsesWith(UndefValue::get(Inst.getType()));
  41           InstToDelete.push_back(&Inst);
  42         }
  43
  44   for (auto &I : InstToDelete)
  45     I->eraseFromParent();
  46 }
  47
  48 /// Counts the amount of basic blocks and prints their name & respective index
  49 static unsigned countInstructions(Module *Program) {
  50   // TODO: Silence index with --quiet flag
  51   outs() << "----------------------------\n";
  52   int InstCount = 0;
  53   for (auto &F : *Program)
  54     for (auto &BB : F)
  55         InstCount += BB.getInstList().size();
  56   outs() << "Number of instructions: " << InstCount << "\n";
  57
  58   return InstCount;
  59 }
  60
  61 void llvm::reduceInstructionsDeltaPass(TestRunner &Test) {
  62   outs() << "*** Reducing Insructions...\n";
  63   unsigned InstCount = countInstructions(Test.getProgram());
  64   runDeltaPass(Test, InstCount, extractInstrFromModule);
  65 }