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   // Keep this in sync with computeIRComplexityScoreImpl().
  24   for (Function &F : WorkItem.getModule()) {
  25     for (Instruction &I : instructions(F)) {
  26       if (auto *OBO = dyn_cast<OverflowingBinaryOperator>(&I)) {
  27         if (OBO->hasNoSignedWrap() && !O.shouldKeep())
  28           I.setHasNoSignedWrap(false);
  29         if (OBO->hasNoUnsignedWrap() && !O.shouldKeep())
  30           I.setHasNoUnsignedWrap(false);
  31       } else if (auto *Trunc = dyn_cast<TruncInst>(&I)) {
  32         if (Trunc->hasNoSignedWrap() && !O.shouldKeep())
  33           Trunc->setHasNoSignedWrap(false);
  34         if (Trunc->hasNoUnsignedWrap() && !O.shouldKeep())
  35           Trunc->setHasNoUnsignedWrap(false);
  36       } else if (auto *PE = dyn_cast<PossiblyExactOperator>(&I)) {
  37         if (PE->isExact() && !O.shouldKeep())
  38           I.setIsExact(false);
  39       } else if (auto *NNI = dyn_cast<PossiblyNonNegInst>(&I)) {
  40         if (NNI->hasNonNeg() && !O.shouldKeep())
  41           NNI->setNonNeg(false);
  42       } else if (auto *PDI = dyn_cast<PossiblyDisjointInst>(&I)) {
  43         if (PDI->isDisjoint() && !O.shouldKeep())
  44           PDI->setIsDisjoint(false);
  45       } else if (auto *ICmp = dyn_cast<ICmpInst>(&I)) {
  46         if (ICmp->hasSameSign() && !O.shouldKeep())
  47           ICmp->setSameSign(false);
  48       } else if (auto *GEP = dyn_cast<GetElementPtrInst>(&I)) {
  49         GEPNoWrapFlags NW = GEP->getNoWrapFlags();
  50         if (NW.isInBounds() && !O.shouldKeep())
  51           NW = NW.withoutInBounds();
  52         if (NW.hasNoUnsignedSignedWrap() && !O.shouldKeep())
  53           NW = NW.withoutNoUnsignedSignedWrap();
  54         if (NW.hasNoUnsignedWrap() && !O.shouldKeep())
  55           NW = NW.withoutNoUnsignedWrap();
  56         GEP->setNoWrapFlags(NW);
  57       } else if (auto *FPOp = dyn_cast<FPMathOperator>(&I)) {
  58         FastMathFlags Flags = FPOp->getFastMathFlags();
  59
  60         if (Flags.allowReassoc() && !O.shouldKeep())
  61           Flags.setAllowReassoc(false);
  62
  63         if (Flags.noNaNs() && !O.shouldKeep())
  64           Flags.setNoNaNs(false);
  65
  66         if (Flags.noInfs() && !O.shouldKeep())
  67           Flags.setNoInfs(false);
  68
  69         if (Flags.noSignedZeros() && !O.shouldKeep())
  70           Flags.setNoSignedZeros(false);
  71
  72         if (Flags.allowReciprocal() && !O.shouldKeep())
  73           Flags.setAllowReciprocal(false);
  74
  75         if (Flags.allowContract() && !O.shouldKeep())
  76           Flags.setAllowContract(false);
  77
  78         if (Flags.approxFunc() && !O.shouldKeep())
  79           Flags.setApproxFunc(false);
  80
  81         I.copyFastMathFlags(Flags);
  82       }
  83     }
  84   }
  85 }
  86
  87 void llvm::reduceInstructionFlagsDeltaPass(TestRunner &Test) {
  88   runDeltaPass(Test, reduceFlagsInModule, "Reducing Instruction Flags");
  89 }