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

   1 //===- ReduceInstructionFlags.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 // Try to remove optimization flags on instructions
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "ReduceInstructionFlags.h"
  14 #include "Delta.h"
  15 #include "llvm/IR/InstIterator.h"
  16 #include "llvm/IR/Instruction.h"
  17 #include "llvm/IR/Instructions.h"
  18 #include "llvm/IR/Operator.h"
  19
  20 using namespace llvm;
  21
  22 static void reduceFlagsInModule(Oracle &O, ReducerWorkItem &WorkItem) {
  23   for (Function &F : WorkItem.getModule()) {
  24     for (Instruction &I : instructions(F)) {
  25       if (auto *OBO = dyn_cast<OverflowingBinaryOperator>(&I)) {
  26         if (OBO->hasNoSignedWrap() && !O.shouldKeep())
  27           I.setHasNoSignedWrap(false);
  28         if (OBO->hasNoUnsignedWrap() && !O.shouldKeep())
  29           I.setHasNoUnsignedWrap(false);
  30       } else if (auto *PE = dyn_cast<PossiblyExactOperator>(&I)) {
  31         if (PE->isExact() && !O.shouldKeep())
  32           I.setIsExact(false);
  33       } else if (auto *GEP = dyn_cast<GetElementPtrInst>(&I)) {
  34         if (GEP->isInBounds() && !O.shouldKeep())
  35           GEP->setIsInBounds(false);
  36       } else if (auto *FPOp = dyn_cast<FPMathOperator>(&I)) {
  37         FastMathFlags Flags = FPOp->getFastMathFlags();
  38
  39         if (Flags.allowReassoc() && !O.shouldKeep())
  40           Flags.setAllowReassoc(false);
  41
  42         if (Flags.noNaNs() && !O.shouldKeep())
  43           Flags.setNoNaNs(false);
  44
  45         if (Flags.noInfs() && !O.shouldKeep())
  46           Flags.setNoInfs(false);
  47
  48         if (Flags.noSignedZeros() && !O.shouldKeep())
  49           Flags.setNoSignedZeros(false);
  50
  51         if (Flags.allowReciprocal() && !O.shouldKeep())
  52           Flags.setAllowReciprocal(false);
  53
  54         if (Flags.allowContract() && !O.shouldKeep())
  55           Flags.setAllowContract(false);
  56
  57         if (Flags.approxFunc() && !O.shouldKeep())
  58           Flags.setApproxFunc(false);
  59
  60         I.copyFastMathFlags(Flags);
  61       }
  62     }
  63   }
  64 }
  65
  66 void llvm::reduceInstructionFlagsDeltaPass(TestRunner &Test) {
  67   runDeltaPass(Test, reduceFlagsInModule, "Reducing Instruction Flags");
  68 }