llvm/tools/llvm-reduce/deltas/ReduceUsingSimplifyCFG.cpp

   1 //===- ReduceUsingSimplifyCFG.h - 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 call SimplifyCFG on individual basic blocks.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "ReduceUsingSimplifyCFG.h"
  15 #include "llvm/Analysis/TargetTransformInfo.h"
  16 #include "llvm/IR/Constants.h"
  17 #include "llvm/IR/Instructions.h"
  18 #include "llvm/Transforms/Utils/Local.h"
  19
  20 using namespace llvm;
  21
  22 static void reduceUsingSimplifyCFG(Oracle &O, ReducerWorkItem &WorkItem) {
  23   Module &Program = WorkItem.getModule();
  24   SmallVector<BasicBlock *, 16> ToSimplify;
  25   for (auto &F : Program)
  26     for (auto &BB : F)
  27       if (!O.shouldKeep())
  28         ToSimplify.push_back(&BB);
  29   TargetTransformInfo TTI(Program.getDataLayout());
  30   for (auto *BB : ToSimplify)
  31     simplifyCFG(BB, TTI);
  32 }
  33
  34 void llvm::reduceUsingSimplifyCFGDeltaPass(TestRunner &Test) {
  35   runDeltaPass(Test, reduceUsingSimplifyCFG, "Reducing using SimplifyCFG");
  36 }
  37 static void reduceConditionals(Oracle &O, ReducerWorkItem &WorkItem,
  38                                bool Direction) {
  39   Module &M = WorkItem.getModule();
  40   SmallVector<BasicBlock *, 16> ToSimplify;
  41
  42   for (auto &F : M) {
  43     for (auto &BB : F) {
  44       auto *BR = dyn_cast<BranchInst>(BB.getTerminator());
  45       if (!BR || !BR->isConditional() || O.shouldKeep())
  46         continue;
  47
  48       if (Direction)
  49         BR->setCondition(ConstantInt::getTrue(BR->getContext()));
  50       else
  51         BR->setCondition(ConstantInt::getFalse(BR->getContext()));
  52
  53       ToSimplify.push_back(&BB);
  54     }
  55   }
  56
  57   TargetTransformInfo TTI(M.getDataLayout());
  58   for (auto *BB : ToSimplify)
  59     simplifyCFG(BB, TTI);
  60 }
  61
  62 void llvm::reduceConditionalsTrueDeltaPass(TestRunner &Test) {
  63   runDeltaPass(
  64       Test,
  65       [](Oracle &O, ReducerWorkItem &WorkItem) {
  66         reduceConditionals(O, WorkItem, true);
  67       },
  68       "Reducing conditional branches to true");
  69 }
  70
  71 void llvm::reduceConditionalsFalseDeltaPass(TestRunner &Test) {
  72   runDeltaPass(
  73       Test,
  74       [](Oracle &O, ReducerWorkItem &WorkItem) {
  75         reduceConditionals(O, WorkItem, false);
  76       },
  77       "Reducing conditional branches to false");
  78 }