first batch of changes

1 files changed, 1356 insertions, 0 deletions

diff --git a/instrumentation/split-compares-pass.so.cc b/instrumentation/split-compares-pass.so.cc
new file mode 100644
index 00000000..2fb90e5e
--- /dev/null
+++ b/instrumentation/split-compares-pass.so.cc
@@ -0,0 +1,1356 @@
+/*
+ * Copyright 2016 laf-intel
+ * extended for floating point by Heiko Eißfeldt
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <list>
+#include <string>
+#include <fstream>
+#include <sys/time.h>
+
+#include "llvm/Config/llvm-config.h"
+
+#include "llvm/Pass.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/IR/Module.h"
+
+#include "llvm/IR/IRBuilder.h"
+#if LLVM_VERSION_MAJOR > 3 || \
+    (LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR > 4)
+  #include "llvm/IR/Verifier.h"
+  #include "llvm/IR/DebugInfo.h"
+#else
+  #include "llvm/Analysis/Verifier.h"
+  #include "llvm/DebugInfo.h"
+  #define nullptr 0
+#endif
+
+using namespace llvm;
+#include "afl-llvm-common.h"
+
+namespace {
+
+class SplitComparesTransform : public ModulePass {
+
+ public:
+  static char ID;
+  SplitComparesTransform() : ModulePass(ID) {
+
+    initInstrumentList();
+
+  }
+
+  bool runOnModule(Module &M) override;
+#if LLVM_VERSION_MAJOR >= 4
+  StringRef getPassName() const override {
+
+#else
+  const char *getPassName() const override {
+
+#endif
+    return "simplifies and splits ICMP instructions";
+
+  }
+
+ private:
+  int enableFPSplit;
+
+  size_t splitIntCompares(Module &M, unsigned bitw);
+  size_t splitFPCompares(Module &M);
+  bool   simplifyCompares(Module &M);
+  bool   simplifyFPCompares(Module &M);
+  bool   simplifyIntSignedness(Module &M);
+  size_t nextPowerOfTwo(size_t in);
+
+};
+
+}  // namespace
+
+char SplitComparesTransform::ID = 0;
+
+/* This function splits FCMP instructions with xGE or xLE predicates into two
+ * FCMP instructions with predicate xGT or xLT and EQ */
+bool SplitComparesTransform::simplifyFPCompares(Module &M) {
+
+  LLVMContext &              C = M.getContext();
+  std::vector<Instruction *> fcomps;
+  IntegerType *              Int1Ty = IntegerType::getInt1Ty(C);
+
+  /* iterate over all functions, bbs and instruction and add
+   * all integer comparisons with >= and <= predicates to the icomps vector */
+  for (auto &F : M) {
+
+    if (!isInInstrumentList(&F)) continue;
+
+    for (auto &BB : F) {
+
+      for (auto &IN : BB) {
+
+        CmpInst *selectcmpInst = nullptr;
+
+        if ((selectcmpInst = dyn_cast<CmpInst>(&IN))) {
+
+          if (enableFPSplit &&
+              (selectcmpInst->getPredicate() == CmpInst::FCMP_OGE ||
+               selectcmpInst->getPredicate() == CmpInst::FCMP_UGE ||
+               selectcmpInst->getPredicate() == CmpInst::FCMP_OLE ||
+               selectcmpInst->getPredicate() == CmpInst::FCMP_ULE)) {
+
+            auto op0 = selectcmpInst->getOperand(0);
+            auto op1 = selectcmpInst->getOperand(1);
+
+            Type *TyOp0 = op0->getType();
+            Type *TyOp1 = op1->getType();
+
+            /* this is probably not needed but we do it anyway */
+            if (TyOp0 != TyOp1) { continue; }
+
+            if (TyOp0->isArrayTy() || TyOp0->isVectorTy()) { continue; }
+
+            fcomps.push_back(selectcmpInst);
+
+          }
+
+        }
+
+      }
+
+    }
+
+  }
+
+  if (!fcomps.size()) { return false; }
+
+  /* transform for floating point */
+  for (auto &FcmpInst : fcomps) {
+
+    BasicBlock *bb = FcmpInst->getParent();
+
+    auto op0 = FcmpInst->getOperand(0);
+    auto op1 = FcmpInst->getOperand(1);
+
+    /* find out what the new predicate is going to be */
+    auto               pred = dyn_cast<CmpInst>(FcmpInst)->getPredicate();
+    CmpInst::Predicate new_pred;
+    switch (pred) {
+
+      case CmpInst::FCMP_UGE:
+        new_pred = CmpInst::FCMP_UGT;
+        break;
+      case CmpInst::FCMP_OGE:
+        new_pred = CmpInst::FCMP_OGT;
+        break;
+      case CmpInst::FCMP_ULE:
+        new_pred = CmpInst::FCMP_ULT;
+        break;
+      case CmpInst::FCMP_OLE:
+        new_pred = CmpInst::FCMP_OLT;
+        break;
+      default:  // keep the compiler happy
+        continue;
+
+    }
+
+    /* split before the fcmp instruction */
+    BasicBlock *end_bb = bb->splitBasicBlock(BasicBlock::iterator(FcmpInst));
+
+    /* the old bb now contains a unconditional jump to the new one (end_bb)
+     * we need to delete it later */
+
+    /* create the FCMP instruction with new_pred and add it to the old basic
+     * block bb it is now at the position where the old FcmpInst was */
+    Instruction *fcmp_np;
+    fcmp_np = CmpInst::Create(Instruction::FCmp, new_pred, op0, op1);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()),
+                             fcmp_np);
+
+    /* create a new basic block which holds the new EQ fcmp */
+    Instruction *fcmp_eq;
+    /* insert middle_bb before end_bb */
+    BasicBlock *middle_bb =
+        BasicBlock::Create(C, "injected", end_bb->getParent(), end_bb);
+    fcmp_eq = CmpInst::Create(Instruction::FCmp, CmpInst::FCMP_OEQ, op0, op1);
+    middle_bb->getInstList().push_back(fcmp_eq);
+    /* add an unconditional branch to the end of middle_bb with destination
+     * end_bb */
+    BranchInst::Create(end_bb, middle_bb);
+
+    /* replace the uncond branch with a conditional one, which depends on the
+     * new_pred fcmp. True goes to end, false to the middle (injected) bb */
+    auto term = bb->getTerminator();
+    BranchInst::Create(end_bb, middle_bb, fcmp_np, bb);
+    term->eraseFromParent();
+
+    /* replace the old FcmpInst (which is the first inst in end_bb) with a PHI
+     * inst to wire up the loose ends */
+    PHINode *PN = PHINode::Create(Int1Ty, 2, "");
+    /* the first result depends on the outcome of fcmp_eq */
+    PN->addIncoming(fcmp_eq, middle_bb);
+    /* if the source was the original bb we know that the fcmp_np yielded true
+     * hence we can hardcode this value */
+    PN->addIncoming(ConstantInt::get(Int1Ty, 1), bb);
+    /* replace the old FcmpInst with our new and shiny PHI inst */
+    BasicBlock::iterator ii(FcmpInst);
+    ReplaceInstWithInst(FcmpInst->getParent()->getInstList(), ii, PN);
+
+  }
+
+  return true;
+
+}
+
+/* This function splits ICMP instructions with xGE or xLE predicates into two
+ * ICMP instructions with predicate xGT or xLT and EQ */
+bool SplitComparesTransform::simplifyCompares(Module &M) {
+
+  LLVMContext &              C = M.getContext();
+  std::vector<Instruction *> icomps;
+  IntegerType *              Int1Ty = IntegerType::getInt1Ty(C);
+
+  /* iterate over all functions, bbs and instruction and add
+   * all integer comparisons with >= and <= predicates to the icomps vector */
+  for (auto &F : M) {
+
+    if (!isInInstrumentList(&F)) continue;
+
+    for (auto &BB : F) {
+
+      for (auto &IN : BB) {
+
+        CmpInst *selectcmpInst = nullptr;
+
+        if ((selectcmpInst = dyn_cast<CmpInst>(&IN))) {
+
+          if (selectcmpInst->getPredicate() == CmpInst::ICMP_UGE ||
+              selectcmpInst->getPredicate() == CmpInst::ICMP_SGE ||
+              selectcmpInst->getPredicate() == CmpInst::ICMP_ULE ||
+              selectcmpInst->getPredicate() == CmpInst::ICMP_SLE) {
+
+            auto op0 = selectcmpInst->getOperand(0);
+            auto op1 = selectcmpInst->getOperand(1);
+
+            IntegerType *intTyOp0 = dyn_cast<IntegerType>(op0->getType());
+            IntegerType *intTyOp1 = dyn_cast<IntegerType>(op1->getType());
+
+            /* this is probably not needed but we do it anyway */
+            if (!intTyOp0 || !intTyOp1) { continue; }
+
+            icomps.push_back(selectcmpInst);
+
+          }
+
+        }
+
+      }
+
+    }
+
+  }
+
+  if (!icomps.size()) { return false; }
+
+  for (auto &IcmpInst : icomps) {
+
+    BasicBlock *bb = IcmpInst->getParent();
+
+    auto op0 = IcmpInst->getOperand(0);
+    auto op1 = IcmpInst->getOperand(1);
+
+    /* find out what the new predicate is going to be */
+    auto               pred = dyn_cast<CmpInst>(IcmpInst)->getPredicate();
+    CmpInst::Predicate new_pred;
+    switch (pred) {
+
+      case CmpInst::ICMP_UGE:
+        new_pred = CmpInst::ICMP_UGT;
+        break;
+      case CmpInst::ICMP_SGE:
+        new_pred = CmpInst::ICMP_SGT;
+        break;
+      case CmpInst::ICMP_ULE:
+        new_pred = CmpInst::ICMP_ULT;
+        break;
+      case CmpInst::ICMP_SLE:
+        new_pred = CmpInst::ICMP_SLT;
+        break;
+      default:  // keep the compiler happy
+        continue;
+
+    }
+
+    /* split before the icmp instruction */
+    BasicBlock *end_bb = bb->splitBasicBlock(BasicBlock::iterator(IcmpInst));
+
+    /* the old bb now contains a unconditional jump to the new one (end_bb)
+     * we need to delete it later */
+
+    /* create the ICMP instruction with new_pred and add it to the old basic
+     * block bb it is now at the position where the old IcmpInst was */
+    Instruction *icmp_np;
+    icmp_np = CmpInst::Create(Instruction::ICmp, new_pred, op0, op1);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()),
+                             icmp_np);
+
+    /* create a new basic block which holds the new EQ icmp */
+    Instruction *icmp_eq;
+    /* insert middle_bb before end_bb */
+    BasicBlock *middle_bb =
+        BasicBlock::Create(C, "injected", end_bb->getParent(), end_bb);
+    icmp_eq = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, op0, op1);
+    middle_bb->getInstList().push_back(icmp_eq);
+    /* add an unconditional branch to the end of middle_bb with destination
+     * end_bb */
+    BranchInst::Create(end_bb, middle_bb);
+
+    /* replace the uncond branch with a conditional one, which depends on the
+     * new_pred icmp. True goes to end, false to the middle (injected) bb */
+    auto term = bb->getTerminator();
+    BranchInst::Create(end_bb, middle_bb, icmp_np, bb);
+    term->eraseFromParent();
+
+    /* replace the old IcmpInst (which is the first inst in end_bb) with a PHI
+     * inst to wire up the loose ends */
+    PHINode *PN = PHINode::Create(Int1Ty, 2, "");
+    /* the first result depends on the outcome of icmp_eq */
+    PN->addIncoming(icmp_eq, middle_bb);
+    /* if the source was the original bb we know that the icmp_np yielded true
+     * hence we can hardcode this value */
+    PN->addIncoming(ConstantInt::get(Int1Ty, 1), bb);
+    /* replace the old IcmpInst with our new and shiny PHI inst */
+    BasicBlock::iterator ii(IcmpInst);
+    ReplaceInstWithInst(IcmpInst->getParent()->getInstList(), ii, PN);
+
+  }
+
+  return true;
+
+}
+
+/* this function transforms signed compares to equivalent unsigned compares */
+bool SplitComparesTransform::simplifyIntSignedness(Module &M) {
+
+  LLVMContext &              C = M.getContext();
+  std::vector<Instruction *> icomps;
+  IntegerType *              Int1Ty = IntegerType::getInt1Ty(C);
+
+  /* iterate over all functions, bbs and instructions and add
+   * all signed compares to icomps vector */
+  for (auto &F : M) {
+
+    if (!isInInstrumentList(&F)) continue;
+
+    for (auto &BB : F) {
+
+      for (auto &IN : BB) {
+
+        CmpInst *selectcmpInst = nullptr;
+
+        if ((selectcmpInst = dyn_cast<CmpInst>(&IN))) {
+
+          if (selectcmpInst->getPredicate() == CmpInst::ICMP_SGT ||
+              selectcmpInst->getPredicate() == CmpInst::ICMP_SLT) {
+
+            auto op0 = selectcmpInst->getOperand(0);
+            auto op1 = selectcmpInst->getOperand(1);
+
+            IntegerType *intTyOp0 = dyn_cast<IntegerType>(op0->getType());
+            IntegerType *intTyOp1 = dyn_cast<IntegerType>(op1->getType());
+
+            /* see above */
+            if (!intTyOp0 || !intTyOp1) { continue; }
+
+            /* i think this is not possible but to lazy to look it up */
+            if (intTyOp0->getBitWidth() != intTyOp1->getBitWidth()) {
+
+              continue;
+
+            }
+
+            icomps.push_back(selectcmpInst);
+
+          }
+
+        }
+
+      }
+
+    }
+
+  }
+
+  if (!icomps.size()) { return false; }
+
+  for (auto &IcmpInst : icomps) {
+
+    BasicBlock *bb = IcmpInst->getParent();
+
+    auto op0 = IcmpInst->getOperand(0);
+    auto op1 = IcmpInst->getOperand(1);
+
+    IntegerType *intTyOp0 = dyn_cast<IntegerType>(op0->getType());
+    unsigned     bitw = intTyOp0->getBitWidth();
+    IntegerType *IntType = IntegerType::get(C, bitw);
+
+    /* get the new predicate */
+    auto               pred = dyn_cast<CmpInst>(IcmpInst)->getPredicate();
+    CmpInst::Predicate new_pred;
+    if (pred == CmpInst::ICMP_SGT) {
+
+      new_pred = CmpInst::ICMP_UGT;
+
+    } else {
+
+      new_pred = CmpInst::ICMP_ULT;
+
+    }
+
+    BasicBlock *end_bb = bb->splitBasicBlock(BasicBlock::iterator(IcmpInst));
+
+    /* create a 1 bit compare for the sign bit. to do this shift and trunc
+     * the original operands so only the first bit remains.*/
+    Instruction *s_op0, *t_op0, *s_op1, *t_op1, *icmp_sign_bit;
+
+    s_op0 = BinaryOperator::Create(Instruction::LShr, op0,
+                                   ConstantInt::get(IntType, bitw - 1));
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), s_op0);
+    t_op0 = new TruncInst(s_op0, Int1Ty);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), t_op0);
+
+    s_op1 = BinaryOperator::Create(Instruction::LShr, op1,
+                                   ConstantInt::get(IntType, bitw - 1));
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), s_op1);
+    t_op1 = new TruncInst(s_op1, Int1Ty);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), t_op1);
+
+    /* compare of the sign bits */
+    icmp_sign_bit =
+        CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, t_op0, t_op1);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()),
+                             icmp_sign_bit);
+
+    /* create a new basic block which is executed if the signedness bit is
+     * different */
+    Instruction *icmp_inv_sig_cmp;
+    BasicBlock * sign_bb =
+        BasicBlock::Create(C, "sign", end_bb->getParent(), end_bb);
+    if (pred == CmpInst::ICMP_SGT) {
+
+      /* if we check for > and the op0 positive and op1 negative then the final
+       * result is true. if op0 negative and op1 pos, the cmp must result
+       * in false
+       */
+      icmp_inv_sig_cmp =
+          CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULT, t_op0, t_op1);
+
+    } else {
+
+      /* just the inverse of the above statement */
+      icmp_inv_sig_cmp =
+          CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_UGT, t_op0, t_op1);
+
+    }
+
+    sign_bb->getInstList().push_back(icmp_inv_sig_cmp);
+    BranchInst::Create(end_bb, sign_bb);
+
+    /* create a new bb which is executed if signedness is equal */
+    Instruction *icmp_usign_cmp;
+    BasicBlock * middle_bb =
+        BasicBlock::Create(C, "injected", end_bb->getParent(), end_bb);
+    /* we can do a normal unsigned compare now */
+    icmp_usign_cmp = CmpInst::Create(Instruction::ICmp, new_pred, op0, op1);
+    middle_bb->getInstList().push_back(icmp_usign_cmp);
+    BranchInst::Create(end_bb, middle_bb);
+
+    auto term = bb->getTerminator();
+    /* if the sign is eq do a normal unsigned cmp, else we have to check the
+     * signedness bit */
+    BranchInst::Create(middle_bb, sign_bb, icmp_sign_bit, bb);
+    term->eraseFromParent();
+
+    PHINode *PN = PHINode::Create(Int1Ty, 2, "");
+
+    PN->addIncoming(icmp_usign_cmp, middle_bb);
+    PN->addIncoming(icmp_inv_sig_cmp, sign_bb);
+
+    BasicBlock::iterator ii(IcmpInst);
+    ReplaceInstWithInst(IcmpInst->getParent()->getInstList(), ii, PN);
+
+  }
+
+  return true;
+
+}
+
+size_t SplitComparesTransform::nextPowerOfTwo(size_t in) {
+
+  --in;
+  in |= in >> 1;
+  in |= in >> 2;
+  in |= in >> 4;
+  //  in |= in >> 8;
+  //  in |= in >> 16;
+  return in + 1;
+
+}
+
+/* splits fcmps into two nested fcmps with sign compare and the rest */
+size_t SplitComparesTransform::splitFPCompares(Module &M) {
+
+  size_t count = 0;
+
+  LLVMContext &C = M.getContext();
+
+#if LLVM_VERSION_MAJOR > 3 || \
+    (LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR > 7)
+  const DataLayout &dl = M.getDataLayout();
+
+  /* define unions with floating point and (sign, exponent, mantissa)  triples
+   */
+  if (dl.isLittleEndian()) {
+
+  } else if (dl.isBigEndian()) {
+
+  } else {
+
+    return count;
+
+  }
+
+#endif
+
+  std::vector<CmpInst *> fcomps;
+
+  /* get all EQ, NE, GT, and LT fcmps. if the other two
+   * functions were executed only these four predicates should exist */
+  for (auto &F : M) {
+
+    if (!isInInstrumentList(&F)) continue;
+
+    for (auto &BB : F) {
+
+      for (auto &IN : BB) {
+
+        CmpInst *selectcmpInst = nullptr;
+
+        if ((selectcmpInst = dyn_cast<CmpInst>(&IN))) {
+
+          if (selectcmpInst->getPredicate() == CmpInst::FCMP_OEQ ||
+              selectcmpInst->getPredicate() == CmpInst::FCMP_ONE ||
+              selectcmpInst->getPredicate() == CmpInst::FCMP_UNE ||
+              selectcmpInst->getPredicate() == CmpInst::FCMP_UGT ||
+              selectcmpInst->getPredicate() == CmpInst::FCMP_OGT ||
+              selectcmpInst->getPredicate() == CmpInst::FCMP_ULT ||
+              selectcmpInst->getPredicate() == CmpInst::FCMP_OLT) {
+
+            auto op0 = selectcmpInst->getOperand(0);
+            auto op1 = selectcmpInst->getOperand(1);
+
+            Type *TyOp0 = op0->getType();
+            Type *TyOp1 = op1->getType();
+
+            if (TyOp0 != TyOp1) { continue; }
+
+            if (TyOp0->isArrayTy() || TyOp0->isVectorTy()) { continue; }
+
+            fcomps.push_back(selectcmpInst);
+
+          }
+
+        }
+
+      }
+
+    }
+
+  }
+
+  if (!fcomps.size()) { return count; }
+
+  IntegerType *Int1Ty = IntegerType::getInt1Ty(C);
+
+  for (auto &FcmpInst : fcomps) {
+
+    BasicBlock *bb = FcmpInst->getParent();
+
+    auto op0 = FcmpInst->getOperand(0);
+    auto op1 = FcmpInst->getOperand(1);
+
+    unsigned op_size;
+    op_size = op0->getType()->getPrimitiveSizeInBits();
+
+    if (op_size != op1->getType()->getPrimitiveSizeInBits()) { continue; }
+
+    const unsigned int sizeInBits = op0->getType()->getPrimitiveSizeInBits();
+    const unsigned int precision =
+        sizeInBits == 32
+            ? 24
+            : sizeInBits == 64
+                  ? 53
+                  : sizeInBits == 128 ? 113
+                                      : sizeInBits == 16 ? 11
+                                                         /* sizeInBits == 80 */
+                                                         : 65;
+
+    const unsigned           shiftR_exponent = precision - 1;
+    const unsigned long long mask_fraction =
+        (1ULL << (shiftR_exponent - 1)) | ((1ULL << (shiftR_exponent - 1)) - 1);
+    const unsigned long long mask_exponent =
+        (1ULL << (sizeInBits - precision)) - 1;
+
+    // round up sizes to the next power of two
+    // this should help with integer compare splitting
+    size_t exTySizeBytes = ((sizeInBits - precision + 7) >> 3);
+    size_t frTySizeBytes = ((precision - 1ULL + 7) >> 3);
+
+    IntegerType *IntExponentTy =
+        IntegerType::get(C, nextPowerOfTwo(exTySizeBytes) << 3);
+    IntegerType *IntFractionTy =
+        IntegerType::get(C, nextPowerOfTwo(frTySizeBytes) << 3);
+
+    //    errs() << "Fractions: IntFractionTy size " <<
+    //     IntFractionTy->getPrimitiveSizeInBits() << ", op_size " << op_size <<
+    //     ", mask " << mask_fraction <<
+    //     ", precision " << precision << "\n";
+
+    BasicBlock *end_bb = bb->splitBasicBlock(BasicBlock::iterator(FcmpInst));
+
+    /* create the integers from floats directly */
+    Instruction *b_op0, *b_op1;
+    b_op0 = CastInst::Create(Instruction::BitCast, op0,
+                             IntegerType::get(C, op_size));
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), b_op0);
+
+    b_op1 = CastInst::Create(Instruction::BitCast, op1,
+                             IntegerType::get(C, op_size));
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), b_op1);
+
+    /* isolate signs of value of floating point type */
+
+    /* create a 1 bit compare for the sign bit. to do this shift and trunc
+     * the original operands so only the first bit remains.*/
+    Instruction *s_s0, *t_s0, *s_s1, *t_s1, *icmp_sign_bit;
+
+    s_s0 =
+        BinaryOperator::Create(Instruction::LShr, b_op0,
+                               ConstantInt::get(b_op0->getType(), op_size - 1));
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), s_s0);
+    t_s0 = new TruncInst(s_s0, Int1Ty);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), t_s0);
+
+    s_s1 =
+        BinaryOperator::Create(Instruction::LShr, b_op1,
+                               ConstantInt::get(b_op1->getType(), op_size - 1));
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), s_s1);
+    t_s1 = new TruncInst(s_s1, Int1Ty);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), t_s1);
+
+    /* compare of the sign bits */
+    icmp_sign_bit =
+        CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, t_s0, t_s1);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()),
+                             icmp_sign_bit);
+
+    /* create a new basic block which is executed if the signedness bits are
+     * equal */
+    BasicBlock *signequal_bb =
+        BasicBlock::Create(C, "signequal", end_bb->getParent(), end_bb);
+
+    BranchInst::Create(end_bb, signequal_bb);
+
+    /* create a new bb which is executed if exponents are satisfying the compare
+     */
+    BasicBlock *middle_bb =
+        BasicBlock::Create(C, "injected", end_bb->getParent(), end_bb);
+
+    BranchInst::Create(end_bb, middle_bb);
+
+    auto term = bb->getTerminator();
+    /* if the signs are different goto end_bb else to signequal_bb */
+    BranchInst::Create(signequal_bb, end_bb, icmp_sign_bit, bb);
+    term->eraseFromParent();
+
+    /* insert code for equal signs */
+
+    /* isolate the exponents */
+    Instruction *s_e0, *m_e0, *t_e0, *s_e1, *m_e1, *t_e1;
+
+    s_e0 = BinaryOperator::Create(
+        Instruction::LShr, b_op0,
+        ConstantInt::get(b_op0->getType(), shiftR_exponent));
+    s_e1 = BinaryOperator::Create(
+        Instruction::LShr, b_op1,
+        ConstantInt::get(b_op1->getType(), shiftR_exponent));
+    signequal_bb->getInstList().insert(
+        BasicBlock::iterator(signequal_bb->getTerminator()), s_e0);
+    signequal_bb->getInstList().insert(
+        BasicBlock::iterator(signequal_bb->getTerminator()), s_e1);
+
+    t_e0 = new TruncInst(s_e0, IntExponentTy);
+    t_e1 = new TruncInst(s_e1, IntExponentTy);
+    signequal_bb->getInstList().insert(
+        BasicBlock::iterator(signequal_bb->getTerminator()), t_e0);
+    signequal_bb->getInstList().insert(
+        BasicBlock::iterator(signequal_bb->getTerminator()), t_e1);
+
+    if (sizeInBits - precision < exTySizeBytes * 8) {
+
+      m_e0 = BinaryOperator::Create(
+          Instruction::And, t_e0,
+          ConstantInt::get(t_e0->getType(), mask_exponent));
+      m_e1 = BinaryOperator::Create(
+          Instruction::And, t_e1,
+          ConstantInt::get(t_e1->getType(), mask_exponent));
+      signequal_bb->getInstList().insert(
+          BasicBlock::iterator(signequal_bb->getTerminator()), m_e0);
+      signequal_bb->getInstList().insert(
+          BasicBlock::iterator(signequal_bb->getTerminator()), m_e1);
+
+    } else {
+
+      m_e0 = t_e0;
+      m_e1 = t_e1;
+
+    }
+
+    /* compare the exponents of the operands */
+    Instruction *icmp_exponents_equal;
+    Instruction *icmp_exponent_result;
+    BasicBlock * signequal2_bb = signequal_bb;
+    switch (FcmpInst->getPredicate()) {
+
+      case CmpInst::FCMP_OEQ:
+        icmp_exponent_result =
+            CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, m_e0, m_e1);
+        break;
+      case CmpInst::FCMP_ONE:
+      case CmpInst::FCMP_UNE:
+        icmp_exponent_result =
+            CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_NE, m_e0, m_e1);
+        break;
+      /* compare the exponents of the operands (signs are equal)
+       * if exponents are equal -> proceed to mantissa comparison
+       * else get result depending on sign
+       */
+      case CmpInst::FCMP_OGT:
+      case CmpInst::FCMP_UGT:
+        Instruction *icmp_exponent;
+        icmp_exponents_equal =
+            CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, m_e0, m_e1);
+        signequal_bb->getInstList().insert(
+            BasicBlock::iterator(signequal_bb->getTerminator()),
+            icmp_exponents_equal);
+
+        // shortcut for unequal exponents
+        signequal2_bb = signequal_bb->splitBasicBlock(
+            BasicBlock::iterator(signequal_bb->getTerminator()));
+
+        /* if the exponents are equal goto middle_bb else to signequal2_bb */
+        term = signequal_bb->getTerminator();
+        BranchInst::Create(middle_bb, signequal2_bb, icmp_exponents_equal,
+                           signequal_bb);
+        term->eraseFromParent();
+
+        icmp_exponent =
+            CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_UGT, m_e0, m_e1);
+        signequal2_bb->getInstList().insert(
+            BasicBlock::iterator(signequal2_bb->getTerminator()),
+            icmp_exponent);
+        icmp_exponent_result =
+            BinaryOperator::Create(Instruction::Xor, icmp_exponent, t_s0);
+        break;
+      case CmpInst::FCMP_OLT:
+      case CmpInst::FCMP_ULT:
+        icmp_exponents_equal =
+            CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, m_e0, m_e1);
+        signequal_bb->getInstList().insert(
+            BasicBlock::iterator(signequal_bb->getTerminator()),
+            icmp_exponents_equal);
+
+        // shortcut for unequal exponents
+        signequal2_bb = signequal_bb->splitBasicBlock(
+            BasicBlock::iterator(signequal_bb->getTerminator()));
+
+        /* if the exponents are equal goto middle_bb else to signequal2_bb */
+        term = signequal_bb->getTerminator();
+        BranchInst::Create(middle_bb, signequal2_bb, icmp_exponents_equal,
+                           signequal_bb);
+        term->eraseFromParent();
+
+        icmp_exponent =
+            CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULT, m_e0, m_e1);
+        signequal2_bb->getInstList().insert(
+            BasicBlock::iterator(signequal2_bb->getTerminator()),
+            icmp_exponent);
+        icmp_exponent_result =
+            BinaryOperator::Create(Instruction::Xor, icmp_exponent, t_s0);
+        break;
+      default:
+        continue;
+
+    }
+
+    signequal2_bb->getInstList().insert(
+        BasicBlock::iterator(signequal2_bb->getTerminator()),
+        icmp_exponent_result);
+
+    {
+
+      term = signequal2_bb->getTerminator();
+
+      switch (FcmpInst->getPredicate()) {
+
+        case CmpInst::FCMP_OEQ:
+          /* if the exponents are satifying the compare do a fraction cmp in
+           * middle_bb */
+          BranchInst::Create(middle_bb, end_bb, icmp_exponent_result,
+                             signequal2_bb);
+          break;
+        case CmpInst::FCMP_ONE:
+        case CmpInst::FCMP_UNE:
+          /* if the exponents are satifying the compare do a fraction cmp in
+           * middle_bb */
+          BranchInst::Create(end_bb, middle_bb, icmp_exponent_result,
+                             signequal2_bb);
+          break;
+        case CmpInst::FCMP_OGT:
+        case CmpInst::FCMP_UGT:
+        case CmpInst::FCMP_OLT:
+        case CmpInst::FCMP_ULT:
+          BranchInst::Create(end_bb, signequal2_bb);
+          break;
+        default:
+          continue;
+
+      }
+
+      term->eraseFromParent();
+
+    }
+
+    /* isolate the mantissa aka fraction */
+    Instruction *t_f0, *t_f1;
+    bool         needTrunc = IntFractionTy->getPrimitiveSizeInBits() < op_size;
+
+    if (precision - 1 < frTySizeBytes * 8) {
+
+      Instruction *m_f0, *m_f1;
+      m_f0 = BinaryOperator::Create(
+          Instruction::And, b_op0,
+          ConstantInt::get(b_op0->getType(), mask_fraction));
+      m_f1 = BinaryOperator::Create(
+          Instruction::And, b_op1,
+          ConstantInt::get(b_op1->getType(), mask_fraction));
+      middle_bb->getInstList().insert(
+          BasicBlock::iterator(middle_bb->getTerminator()), m_f0);
+      middle_bb->getInstList().insert(
+          BasicBlock::iterator(middle_bb->getTerminator()), m_f1);
+
+      if (needTrunc) {
+
+        t_f0 = new TruncInst(m_f0, IntFractionTy);
+        t_f1 = new TruncInst(m_f1, IntFractionTy);
+        middle_bb->getInstList().insert(
+            BasicBlock::iterator(middle_bb->getTerminator()), t_f0);
+        middle_bb->getInstList().insert(
+            BasicBlock::iterator(middle_bb->getTerminator()), t_f1);
+
+      } else {
+
+        t_f0 = m_f0;
+        t_f1 = m_f1;
+
+      }
+
+    } else {
+
+      if (needTrunc) {
+
+        t_f0 = new TruncInst(b_op0, IntFractionTy);
+        t_f1 = new TruncInst(b_op1, IntFractionTy);
+        middle_bb->getInstList().insert(
+            BasicBlock::iterator(middle_bb->getTerminator()), t_f0);
+        middle_bb->getInstList().insert(
+            BasicBlock::iterator(middle_bb->getTerminator()), t_f1);
+
+      } else {
+
+        t_f0 = b_op0;
+        t_f1 = b_op1;
+
+      }
+
+    }
+
+    /* compare the fractions of the operands */
+    Instruction *icmp_fraction_result;
+    Instruction *icmp_fraction_result2;
+    BasicBlock * middle2_bb = middle_bb;
+    PHINode *    PN2 = nullptr;
+    switch (FcmpInst->getPredicate()) {
+
+      case CmpInst::FCMP_OEQ:
+        icmp_fraction_result =
+            CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, t_f0, t_f1);
+        middle2_bb->getInstList().insert(
+            BasicBlock::iterator(middle2_bb->getTerminator()),
+            icmp_fraction_result);
+
+        break;
+      case CmpInst::FCMP_UNE:
+      case CmpInst::FCMP_ONE:
+        icmp_fraction_result =
+            CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_NE, t_f0, t_f1);
+        middle2_bb->getInstList().insert(
+            BasicBlock::iterator(middle2_bb->getTerminator()),
+            icmp_fraction_result);
+
+        break;
+      case CmpInst::FCMP_OGT:
+      case CmpInst::FCMP_UGT:
+      case CmpInst::FCMP_OLT:
+      case CmpInst::FCMP_ULT: {
+
+        middle2_bb = middle_bb->splitBasicBlock(
+            BasicBlock::iterator(middle_bb->getTerminator()));
+
+        BasicBlock *negative_bb = BasicBlock::Create(
+            C, "negative_value", middle2_bb->getParent(), middle2_bb);
+        BasicBlock *positive_bb = BasicBlock::Create(
+            C, "positive_value", negative_bb->getParent(), negative_bb);
+
+        if (FcmpInst->getPredicate() == CmpInst::FCMP_OGT ||
+            FcmpInst->getPredicate() == CmpInst::FCMP_UGT) {
+
+          negative_bb->getInstList().push_back(
+              icmp_fraction_result = CmpInst::Create(
+                  Instruction::ICmp, CmpInst::ICMP_ULT, t_f0, t_f1));
+          positive_bb->getInstList().push_back(
+              icmp_fraction_result2 = CmpInst::Create(
+                  Instruction::ICmp, CmpInst::ICMP_UGT, t_f0, t_f1));
+
+        } else {
+
+          negative_bb->getInstList().push_back(
+              icmp_fraction_result = CmpInst::Create(
+                  Instruction::ICmp, CmpInst::ICMP_UGT, t_f0, t_f1));
+          positive_bb->getInstList().push_back(
+              icmp_fraction_result2 = CmpInst::Create(
+                  Instruction::ICmp, CmpInst::ICMP_ULT, t_f0, t_f1));
+
+        }
+
+        BranchInst::Create(middle2_bb, negative_bb);
+        BranchInst::Create(middle2_bb, positive_bb);
+
+        term = middle_bb->getTerminator();
+        BranchInst::Create(negative_bb, positive_bb, t_s0, middle_bb);
+        term->eraseFromParent();
+
+        PN2 = PHINode::Create(Int1Ty, 2, "");
+        PN2->addIncoming(icmp_fraction_result, negative_bb);
+        PN2->addIncoming(icmp_fraction_result2, positive_bb);
+        middle2_bb->getInstList().insert(
+            BasicBlock::iterator(middle2_bb->getTerminator()), PN2);
+
+      } break;
+
+      default:
+        continue;
+
+    }
+
+    PHINode *PN = PHINode::Create(Int1Ty, 3, "");
+
+    switch (FcmpInst->getPredicate()) {
+
+      case CmpInst::FCMP_OEQ:
+        /* unequal signs cannot be equal values */
+        /* goto false branch */
+        PN->addIncoming(ConstantInt::get(Int1Ty, 0), bb);
+        /* unequal exponents cannot be equal values, too */
+        PN->addIncoming(ConstantInt::get(Int1Ty, 0), signequal_bb);
+        /* fractions comparison */
+        PN->addIncoming(icmp_fraction_result, middle2_bb);
+        break;
+      case CmpInst::FCMP_ONE:
+      case CmpInst::FCMP_UNE:
+        /* unequal signs are unequal values */
+        /* goto true branch */
+        PN->addIncoming(ConstantInt::get(Int1Ty, 1), bb);
+        /* unequal exponents are unequal values, too */
+        PN->addIncoming(icmp_exponent_result, signequal_bb);
+        /* fractions comparison */
+        PN->addIncoming(icmp_fraction_result, middle2_bb);
+        break;
+      case CmpInst::FCMP_OGT:
+      case CmpInst::FCMP_UGT:
+        /* if op1 is negative goto true branch,
+           else go on comparing */
+        PN->addIncoming(t_s1, bb);
+        PN->addIncoming(icmp_exponent_result, signequal2_bb);
+        PN->addIncoming(PN2, middle2_bb);
+        break;
+      case CmpInst::FCMP_OLT:
+      case CmpInst::FCMP_ULT:
+        /* if op0 is negative goto true branch,
+           else go on comparing */
+        PN->addIncoming(t_s0, bb);
+        PN->addIncoming(icmp_exponent_result, signequal2_bb);
+        PN->addIncoming(PN2, middle2_bb);
+        break;
+      default:
+        continue;
+
+    }
+
+    BasicBlock::iterator ii(FcmpInst);
+    ReplaceInstWithInst(FcmpInst->getParent()->getInstList(), ii, PN);
+    ++count;
+
+  }
+
+  return count;
+
+}
+
+/* splits icmps of size bitw into two nested icmps with bitw/2 size each */
+size_t SplitComparesTransform::splitIntCompares(Module &M, unsigned bitw) {
+
+  size_t count = 0;
+
+  LLVMContext &C = M.getContext();
+
+  IntegerType *Int1Ty = IntegerType::getInt1Ty(C);
+  IntegerType *OldIntType = IntegerType::get(C, bitw);
+  IntegerType *NewIntType = IntegerType::get(C, bitw / 2);
+
+  std::vector<Instruction *> icomps;
+
+  if (bitw % 2) { return 0; }
+
+  /* not supported yet */
+  if (bitw > 64) { return 0; }
+
+  /* get all EQ, NE, UGT, and ULT icmps of width bitw. if the
+   * functions simplifyCompares() and simplifyIntSignedness()
+   * were executed only these four predicates should exist */
+  for (auto &F : M) {
+
+    if (!isInInstrumentList(&F)) continue;
+
+    for (auto &BB : F) {
+
+      for (auto &IN : BB) {
+
+        CmpInst *selectcmpInst = nullptr;
+
+        if ((selectcmpInst = dyn_cast<CmpInst>(&IN))) {
+
+          if (selectcmpInst->getPredicate() == CmpInst::ICMP_EQ ||
+              selectcmpInst->getPredicate() == CmpInst::ICMP_NE ||
+              selectcmpInst->getPredicate() == CmpInst::ICMP_UGT ||
+              selectcmpInst->getPredicate() == CmpInst::ICMP_ULT) {
+
+            auto op0 = selectcmpInst->getOperand(0);
+            auto op1 = selectcmpInst->getOperand(1);
+
+            IntegerType *intTyOp0 = dyn_cast<IntegerType>(op0->getType());
+            IntegerType *intTyOp1 = dyn_cast<IntegerType>(op1->getType());
+
+            if (!intTyOp0 || !intTyOp1) { continue; }
+
+            /* check if the bitwidths are the one we are looking for */
+            if (intTyOp0->getBitWidth() != bitw ||
+                intTyOp1->getBitWidth() != bitw) {
+
+              continue;
+
+            }
+
+            icomps.push_back(selectcmpInst);
+
+          }
+
+        }
+
+      }
+
+    }
+
+  }
+
+  if (!icomps.size()) { return 0; }
+
+  for (auto &IcmpInst : icomps) {
+
+    BasicBlock *bb = IcmpInst->getParent();
+
+    auto op0 = IcmpInst->getOperand(0);
+    auto op1 = IcmpInst->getOperand(1);
+
+    auto pred = dyn_cast<CmpInst>(IcmpInst)->getPredicate();
+
+    BasicBlock *end_bb = bb->splitBasicBlock(BasicBlock::iterator(IcmpInst));
+
+    /* create the comparison of the top halves of the original operands */
+    Instruction *s_op0, *op0_high, *s_op1, *op1_high, *icmp_high;
+
+    s_op0 = BinaryOperator::Create(Instruction::LShr, op0,
+                                   ConstantInt::get(OldIntType, bitw / 2));
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), s_op0);
+    op0_high = new TruncInst(s_op0, NewIntType);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()),
+                             op0_high);
+
+    s_op1 = BinaryOperator::Create(Instruction::LShr, op1,
+                                   ConstantInt::get(OldIntType, bitw / 2));
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()), s_op1);
+    op1_high = new TruncInst(s_op1, NewIntType);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()),
+                             op1_high);
+
+    icmp_high = CmpInst::Create(Instruction::ICmp, pred, op0_high, op1_high);
+    bb->getInstList().insert(BasicBlock::iterator(bb->getTerminator()),
+                             icmp_high);
+
+    /* now we have to destinguish between == != and > < */
+    if (pred == CmpInst::ICMP_EQ || pred == CmpInst::ICMP_NE) {
+
+      /* transformation for == and != icmps */
+
+      /* create a compare for the lower half of the original operands */
+      Instruction *op0_low, *op1_low, *icmp_low;
+      BasicBlock * cmp_low_bb =
+          BasicBlock::Create(C, "injected", end_bb->getParent(), end_bb);
+
+      op0_low = new TruncInst(op0, NewIntType);
+      cmp_low_bb->getInstList().push_back(op0_low);
+
+      op1_low = new TruncInst(op1, NewIntType);
+      cmp_low_bb->getInstList().push_back(op1_low);
+
+      icmp_low = CmpInst::Create(Instruction::ICmp, pred, op0_low, op1_low);
+      cmp_low_bb->getInstList().push_back(icmp_low);
+      BranchInst::Create(end_bb, cmp_low_bb);
+
+      /* dependent on the cmp of the high parts go to the end or go on with
+       * the comparison */
+      auto term = bb->getTerminator();
+      if (pred == CmpInst::ICMP_EQ) {
+
+        BranchInst::Create(cmp_low_bb, end_bb, icmp_high, bb);
+
+      } else {
+
+        /* CmpInst::ICMP_NE */
+        BranchInst::Create(end_bb, cmp_low_bb, icmp_high, bb);
+
+      }
+
+      term->eraseFromParent();
+
+      /* create the PHI and connect the edges accordingly */
+      PHINode *PN = PHINode::Create(Int1Ty, 2, "");
+      PN->addIncoming(icmp_low, cmp_low_bb);
+      if (pred == CmpInst::ICMP_EQ) {
+
+        PN->addIncoming(ConstantInt::get(Int1Ty, 0), bb);
+
+      } else {
+
+        /* CmpInst::ICMP_NE */
+        PN->addIncoming(ConstantInt::get(Int1Ty, 1), bb);
+
+      }
+
+      /* replace the old icmp with the new PHI */
+      BasicBlock::iterator ii(IcmpInst);
+      ReplaceInstWithInst(IcmpInst->getParent()->getInstList(), ii, PN);
+
+    } else {
+
+      /* CmpInst::ICMP_UGT and CmpInst::ICMP_ULT */
+      /* transformations for < and > */
+
+      /* create a basic block which checks for the inverse predicate.
+       * if this is true we can go to the end if not we have to go to the
+       * bb which checks the lower half of the operands */
+      Instruction *icmp_inv_cmp, *op0_low, *op1_low, *icmp_low;
+      BasicBlock * inv_cmp_bb =
+          BasicBlock::Create(C, "inv_cmp", end_bb->getParent(), end_bb);
+      if (pred == CmpInst::ICMP_UGT) {
+
+        icmp_inv_cmp = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULT,
+                                       op0_high, op1_high);
+
+      } else {
+
+        icmp_inv_cmp = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_UGT,
+                                       op0_high, op1_high);
+
+      }
+
+      inv_cmp_bb->getInstList().push_back(icmp_inv_cmp);
+
+      auto term = bb->getTerminator();
+      term->eraseFromParent();
+      BranchInst::Create(end_bb, inv_cmp_bb, icmp_high, bb);
+
+      /* create a bb which handles the cmp of the lower halves */
+      BasicBlock *cmp_low_bb =
+          BasicBlock::Create(C, "injected", end_bb->getParent(), end_bb);
+      op0_low = new TruncInst(op0, NewIntType);
+      cmp_low_bb->getInstList().push_back(op0_low);
+      op1_low = new TruncInst(op1, NewIntType);
+      cmp_low_bb->getInstList().push_back(op1_low);
+
+      icmp_low = CmpInst::Create(Instruction::ICmp, pred, op0_low, op1_low);
+      cmp_low_bb->getInstList().push_back(icmp_low);
+      BranchInst::Create(end_bb, cmp_low_bb);
+
+      BranchInst::Create(end_bb, cmp_low_bb, icmp_inv_cmp, inv_cmp_bb);
+
+      PHINode *PN = PHINode::Create(Int1Ty, 3);
+      PN->addIncoming(icmp_low, cmp_low_bb);
+      PN->addIncoming(ConstantInt::get(Int1Ty, 1), bb);
+      PN->addIncoming(ConstantInt::get(Int1Ty, 0), inv_cmp_bb);
+
+      BasicBlock::iterator ii(IcmpInst);
+      ReplaceInstWithInst(IcmpInst->getParent()->getInstList(), ii, PN);
+
+    }
+
+    ++count;
+
+  }
+
+  return count;
+
+}
+
+bool SplitComparesTransform::runOnModule(Module &M) {
+
+  int    bitw = 64;
+  size_t count;
+
+  char *bitw_env = getenv("AFL_LLVM_LAF_SPLIT_COMPARES_BITW");
+  if (!bitw_env) bitw_env = getenv("LAF_SPLIT_COMPARES_BITW");
+  if (bitw_env) { bitw = atoi(bitw_env); }
+
+  enableFPSplit = getenv("AFL_LLVM_LAF_SPLIT_FLOATS") != NULL;
+
+  if ((isatty(2) && getenv("AFL_QUIET") == NULL) ||
+      getenv("AFL_DEBUG") != NULL) {
+
+    errs() << "Split-compare-pass by laf.intel@gmail.com, extended by "
+              "heiko@hexco.de\n";
+
+  } else {
+
+    be_quiet = 1;
+
+  }
+
+  if (enableFPSplit) {
+
+    count = splitFPCompares(M);
+
+    if (!be_quiet) {
+
+      errs() << "Split-floatingpoint-compare-pass: " << count
+             << " FP comparisons split\n";
+
+    }
+
+    simplifyFPCompares(M);
+
+  }
+
+  simplifyCompares(M);
+
+  simplifyIntSignedness(M);
+
+  switch (bitw) {
+
+    case 64:
+      count = splitIntCompares(M, bitw);
+      if (!be_quiet)
+        errs() << "Split-integer-compare-pass " << bitw << "bit: " << count
+               << " split\n";
+
+      bitw >>= 1;
+#if LLVM_VERSION_MAJOR > 3 || \
+    (LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR > 7)
+      [[clang::fallthrough]]; /*FALLTHRU*/                   /* FALLTHROUGH */
+#endif
+    case 32:
+      count = splitIntCompares(M, bitw);
+      if (!be_quiet)
+        errs() << "Split-integer-compare-pass " << bitw << "bit: " << count
+               << " split\n";
+
+      bitw >>= 1;
+#if LLVM_VERSION_MAJOR > 3 || \
+    (LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR > 7)
+      [[clang::fallthrough]]; /*FALLTHRU*/                   /* FALLTHROUGH */
+#endif
+    case 16:
+      count = splitIntCompares(M, bitw);
+      if (!be_quiet)
+        errs() << "Split-integer-compare-pass " << bitw << "bit: " << count
+               << " split\n";
+
+      bitw >>= 1;
+      break;
+
+    default:
+      if (!be_quiet) errs() << "NOT Running split-compare-pass \n";
+      return false;
+      break;
+
+  }
+
+  verifyModule(M);
+  return true;
+
+}
+
+static void registerSplitComparesPass(const PassManagerBuilder &,
+                                      legacy::PassManagerBase &PM) {
+
+  PM.add(new SplitComparesTransform());
+
+}
+
+static RegisterStandardPasses RegisterSplitComparesPass(
+    PassManagerBuilder::EP_OptimizerLast, registerSplitComparesPass);
+
+static RegisterStandardPasses RegisterSplitComparesTransPass0(
+    PassManagerBuilder::EP_EnabledOnOptLevel0, registerSplitComparesPass);
+
+#if LLVM_VERSION_MAJOR >= 11
+static RegisterStandardPasses RegisterSplitComparesTransPassLTO(
+    PassManagerBuilder::EP_FullLinkTimeOptimizationLast,
+    registerSplitComparesPass);
+#endif
+