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laf-intel.diff
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diff -urN ./laf-intel.usage ./laf-intel.usage
--- ./laf-intel.usage 1970-01-01 01:00:00.000000000 +0100
+++ ./laf-intel.usage 2019-01-09 21:41:01.928365797 +0100
@@ -0,0 +1,13 @@
+Usage
+By default the passes will not run when you compile programs using
+afl-clang-fast. Hence, you can use AFL as usual. To enable the passes you must
+set environment variables before you compile the target project.
+
+
+export LAF_SPLIT_SWITCHES=1 Enables the split-switches pass.
+
+export LAF_TRANSFORM_COMPARES=1 Enables the transform-compares pass (strcmp, memcmp, strncmp, strcasecmp, strncasecmp).
+
+export LAF_SPLIT_COMPARES=1 Enables the split-compares pass. By default it will split all compares with
+a bit width <= 64 bits. You can change this behaviour by setting export LAF_SPLIT_COMPARES_BITW=<bit_width>.
+
diff -urN ./llvm_mode/afl-clang-fast.c ./llvm_mode/afl-clang-fast.c
--- ./llvm_mode/afl-clang-fast.c 2017-01-25 03:51:26.000000000 +0100
+++ ./llvm_mode/afl-clang-fast.c 2018-12-27 15:23:41.710341000 +0100
@@ -119,6 +119,29 @@
http://clang.llvm.org/docs/SanitizerCoverage.html#tracing-pcs-with-guards */
+ // laf
+ if (getenv("LAF_SPLIT_SWITCHES")) {
+ cc_params[cc_par_cnt++] = "-Xclang";
+ cc_params[cc_par_cnt++] = "-load";
+ cc_params[cc_par_cnt++] = "-Xclang";
+ cc_params[cc_par_cnt++] = alloc_printf("%s/split-switches-pass.so", obj_path);
+ }
+
+ if (getenv("LAF_TRANSFORM_COMPARES")) {
+ cc_params[cc_par_cnt++] = "-Xclang";
+ cc_params[cc_par_cnt++] = "-load";
+ cc_params[cc_par_cnt++] = "-Xclang";
+ cc_params[cc_par_cnt++] = alloc_printf("%s/compare-transform-pass.so", obj_path);
+ }
+
+ if (getenv("LAF_SPLIT_COMPARES")) {
+ cc_params[cc_par_cnt++] = "-Xclang";
+ cc_params[cc_par_cnt++] = "-load";
+ cc_params[cc_par_cnt++] = "-Xclang";
+ cc_params[cc_par_cnt++] = alloc_printf("%s/split-compares-pass.so", obj_path);
+ }
+ // /laf
+
#ifdef USE_TRACE_PC
cc_params[cc_par_cnt++] = "-fsanitize-coverage=trace-pc-guard";
cc_params[cc_par_cnt++] = "-mllvm";
diff -urN ./llvm_mode/compare-transform-pass.so.cc ./llvm_mode/compare-transform-pass.so.cc
--- ./llvm_mode/compare-transform-pass.so.cc 1970-01-01 01:00:00.000000000 +0100
+++ ./llvm_mode/compare-transform-pass.so.cc 2019-01-09 22:36:59.184886414 +0100
@@ -0,0 +1,307 @@
+/*
+ * Copyright 2016 laf-intel
+ *
+ * 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 "llvm/ADT/Statistic.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Pass.h"
+#include "llvm/Analysis/ValueTracking.h"
+
+#include <set>
+
+using namespace llvm;
+
+namespace {
+
+ class CompareTransform : public ModulePass {
+
+ public:
+ static char ID;
+ CompareTransform() : ModulePass(ID) {
+ }
+
+ bool runOnModule(Module &M) override;
+
+#if __clang_major__ < 4
+ const char * getPassName() const override {
+#else
+ StringRef getPassName() const override {
+#endif
+ return "transforms compare functions";
+ }
+ private:
+ bool transformCmps(Module &M, const bool processStrcmp, const bool processMemcmp
+ ,const bool processStrncmp, const bool processStrcasecmp, const bool processStrncasecmp);
+ };
+}
+
+
+char CompareTransform::ID = 0;
+
+bool CompareTransform::transformCmps(Module &M, const bool processStrcmp, const bool processMemcmp
+ , const bool processStrncmp, const bool processStrcasecmp, const bool processStrncasecmp) {
+
+ std::vector<CallInst*> calls;
+ LLVMContext &C = M.getContext();
+ IntegerType *Int8Ty = IntegerType::getInt8Ty(C);
+ IntegerType *Int32Ty = IntegerType::getInt32Ty(C);
+ IntegerType *Int64Ty = IntegerType::getInt64Ty(C);
+ Constant* c = M.getOrInsertFunction("tolower",
+ Int32Ty,
+ Int32Ty
+#if __clang_major__ < 7
+ , nullptr
+#endif
+ );
+ Function* tolowerFn = cast<Function>(c);
+
+ /* iterate over all functions, bbs and instruction and add suitable calls to strcmp/memcmp/strncmp/strcasecmp/strncasecmp */
+ for (auto &F : M) {
+ for (auto &BB : F) {
+ for(auto &IN: BB) {
+ CallInst* callInst = nullptr;
+
+ if ((callInst = dyn_cast<CallInst>(&IN))) {
+
+ bool isStrcmp = processStrcmp;
+ bool isMemcmp = processMemcmp;
+ bool isStrncmp = processStrncmp;
+ bool isStrcasecmp = processStrcasecmp;
+ bool isStrncasecmp = processStrncasecmp;
+
+ Function *Callee = callInst->getCalledFunction();
+ if (!Callee)
+ continue;
+ if (callInst->getCallingConv() != llvm::CallingConv::C)
+ continue;
+ StringRef FuncName = Callee->getName();
+ isStrcmp &= !FuncName.compare(StringRef("strcmp"));
+ isMemcmp &= !FuncName.compare(StringRef("memcmp"));
+ isStrncmp &= !FuncName.compare(StringRef("strncmp"));
+ isStrcasecmp &= !FuncName.compare(StringRef("strcasecmp"));
+ isStrncasecmp &= !FuncName.compare(StringRef("strncasecmp"));
+
+ if (!isStrcmp && !isMemcmp && !isStrncmp && !isStrcasecmp && !isStrncasecmp)
+ continue;
+
+ /* Verify the strcmp/memcmp/strncmp/strcasecmp/strncasecmp function prototype */
+ FunctionType *FT = Callee->getFunctionType();
+
+
+ isStrcmp &= FT->getNumParams() == 2 &&
+ FT->getReturnType()->isIntegerTy(32) &&
+ FT->getParamType(0) == FT->getParamType(1) &&
+ FT->getParamType(0) == IntegerType::getInt8PtrTy(M.getContext());
+ isStrcasecmp &= FT->getNumParams() == 2 &&
+ FT->getReturnType()->isIntegerTy(32) &&
+ FT->getParamType(0) == FT->getParamType(1) &&
+ FT->getParamType(0) == IntegerType::getInt8PtrTy(M.getContext());
+ isMemcmp &= FT->getNumParams() == 3 &&
+ FT->getReturnType()->isIntegerTy(32) &&
+ FT->getParamType(0)->isPointerTy() &&
+ FT->getParamType(1)->isPointerTy() &&
+ FT->getParamType(2)->isIntegerTy();
+ isStrncmp &= FT->getNumParams() == 3 &&
+ FT->getReturnType()->isIntegerTy(32) &&
+ FT->getParamType(0) == FT->getParamType(1) &&
+ FT->getParamType(0) == IntegerType::getInt8PtrTy(M.getContext()) &&
+ FT->getParamType(2)->isIntegerTy();
+ isStrncasecmp &= FT->getNumParams() == 3 &&
+ FT->getReturnType()->isIntegerTy(32) &&
+ FT->getParamType(0) == FT->getParamType(1) &&
+ FT->getParamType(0) == IntegerType::getInt8PtrTy(M.getContext()) &&
+ FT->getParamType(2)->isIntegerTy();
+
+ if (!isStrcmp && !isMemcmp && !isStrncmp && !isStrcasecmp && !isStrncasecmp)
+ continue;
+
+ /* is a str{n,}{case,}cmp/memcmp, check is we have
+ * str{case,}cmp(x, "const") or str{case,}cmp("const", x)
+ * strn{case,}cmp(x, "const", ..) or strn{case,}cmp("const", x, ..)
+ * memcmp(x, "const", ..) or memcmp("const", x, ..) */
+ Value *Str1P = callInst->getArgOperand(0), *Str2P = callInst->getArgOperand(1);
+ StringRef Str1, Str2;
+ bool HasStr1 = getConstantStringInfo(Str1P, Str1);
+ bool HasStr2 = getConstantStringInfo(Str2P, Str2);
+
+ /* handle cases of one string is const, one string is variable */
+ if (!(HasStr1 ^ HasStr2))
+ continue;
+
+ if (isMemcmp || isStrncmp || isStrncasecmp) {
+ /* check if third operand is a constant integer
+ * strlen("constStr") and sizeof() are treated as constant */
+ Value *op2 = callInst->getArgOperand(2);
+ ConstantInt* ilen = dyn_cast<ConstantInt>(op2);
+ if (!ilen)
+ continue;
+ /* final precaution: if size of compare is larger than constant string skip it*/
+ uint64_t literalLength = HasStr1 ? GetStringLength(Str1P) : GetStringLength(Str2P);
+ if (literalLength < ilen->getZExtValue())
+ continue;
+ }
+
+ calls.push_back(callInst);
+ }
+ }
+ }
+ }
+
+ if (!calls.size())
+ return false;
+ errs() << "Replacing " << calls.size() << " calls to strcmp/memcmp/strncmp/strcasecmp/strncasecmp\n";
+
+ for (auto &callInst: calls) {
+
+ Value *Str1P = callInst->getArgOperand(0), *Str2P = callInst->getArgOperand(1);
+ StringRef Str1, Str2, ConstStr;
+ Value *VarStr;
+ bool HasStr1 = getConstantStringInfo(Str1P, Str1);
+ getConstantStringInfo(Str2P, Str2);
+ uint64_t constLen, sizedLen;
+ bool isMemcmp = !callInst->getCalledFunction()->getName().compare(StringRef("memcmp"));
+ bool isSizedcmp = isMemcmp
+ || !callInst->getCalledFunction()->getName().compare(StringRef("strncmp"))
+ || !callInst->getCalledFunction()->getName().compare(StringRef("strncasecmp"));
+ bool isCaseInsensitive = !callInst->getCalledFunction()->getName().compare(StringRef("strcasecmp"))
+ || !callInst->getCalledFunction()->getName().compare(StringRef("strncasecmp"));
+
+ if (isSizedcmp) {
+ Value *op2 = callInst->getArgOperand(2);
+ ConstantInt* ilen = dyn_cast<ConstantInt>(op2);
+ sizedLen = ilen->getZExtValue();
+ }
+
+ if (HasStr1) {
+ ConstStr = Str1;
+ VarStr = Str2P;
+ constLen = isMemcmp ? sizedLen : GetStringLength(Str1P);
+ }
+ else {
+ ConstStr = Str2;
+ VarStr = Str1P;
+ constLen = isMemcmp ? sizedLen : GetStringLength(Str2P);
+ }
+ if (isSizedcmp && constLen > sizedLen) {
+ constLen = sizedLen;
+ }
+
+ errs() << callInst->getCalledFunction()->getName() << ": len " << constLen << ": " << ConstStr << "\n";
+
+ /* split before the call instruction */
+ BasicBlock *bb = callInst->getParent();
+ BasicBlock *end_bb = bb->splitBasicBlock(BasicBlock::iterator(callInst));
+ BasicBlock *next_bb = BasicBlock::Create(C, "cmp_added", end_bb->getParent(), end_bb);
+ BranchInst::Create(end_bb, next_bb);
+ PHINode *PN = PHINode::Create(Int32Ty, constLen + 1, "cmp_phi");
+
+ TerminatorInst *term = bb->getTerminator();
+ BranchInst::Create(next_bb, bb);
+ term->eraseFromParent();
+
+ for (uint64_t i = 0; i < constLen; i++) {
+
+ BasicBlock *cur_bb = next_bb;
+
+ char c = isCaseInsensitive ? tolower(ConstStr[i]) : ConstStr[i];
+
+
+ BasicBlock::iterator IP = next_bb->getFirstInsertionPt();
+ IRBuilder<> IRB(&*IP);
+
+ Value* v = ConstantInt::get(Int64Ty, i);
+ Value *ele = IRB.CreateInBoundsGEP(VarStr, v, "empty");
+ Value *load = IRB.CreateLoad(ele);
+ if (isCaseInsensitive) {
+ // load >= 'A' && load <= 'Z' ? load | 0x020 : load
+ std::vector<Value *> args;
+ args.push_back(load);
+ load = IRB.CreateCall(tolowerFn, args, "tmp");
+ }
+ Value *isub;
+ if (HasStr1)
+ isub = IRB.CreateSub(ConstantInt::get(Int8Ty, c), load);
+ else
+ isub = IRB.CreateSub(load, ConstantInt::get(Int8Ty, c));
+
+ Value *sext = IRB.CreateSExt(isub, Int32Ty);
+ PN->addIncoming(sext, cur_bb);
+
+
+ if (i < constLen - 1) {
+ next_bb = BasicBlock::Create(C, "cmp_added", end_bb->getParent(), end_bb);
+ BranchInst::Create(end_bb, next_bb);
+
+ TerminatorInst *term = cur_bb->getTerminator();
+ Value *icmp = IRB.CreateICmpEQ(isub, ConstantInt::get(Int8Ty, 0));
+ IRB.CreateCondBr(icmp, next_bb, end_bb);
+ term->eraseFromParent();
+ } else {
+ //IRB.CreateBr(end_bb);
+ }
+
+ //add offset to varstr
+ //create load
+ //create signed isub
+ //create icmp
+ //create jcc
+ //create next_bb
+ }
+
+ /* since the call is the first instruction of the bb it is safe to
+ * replace it with a phi instruction */
+ BasicBlock::iterator ii(callInst);
+ ReplaceInstWithInst(callInst->getParent()->getInstList(), ii, PN);
+ }
+
+
+ return true;
+}
+
+bool CompareTransform::runOnModule(Module &M) {
+
+ llvm::errs() << "Running compare-transform-pass by laf.intel@gmail.com, extended by heiko@hexco.de\n";
+ transformCmps(M, true, true, true, true, true);
+ verifyModule(M);
+
+ return true;
+}
+
+static void registerCompTransPass(const PassManagerBuilder &,
+ legacy::PassManagerBase &PM) {
+
+ auto p = new CompareTransform();
+ PM.add(p);
+
+}
+
+static RegisterStandardPasses RegisterCompTransPass(
+ PassManagerBuilder::EP_OptimizerLast, registerCompTransPass);
+
+static RegisterStandardPasses RegisterCompTransPass0(
+ PassManagerBuilder::EP_EnabledOnOptLevel0, registerCompTransPass);
+
diff -urN ./llvm_mode/Makefile ./llvm_mode/Makefile
--- ./llvm_mode/Makefile 2016-06-24 04:38:49.000000000 +0200
+++ ./llvm_mode/Makefile 2018-12-27 15:19:18.086346000 +0100
@@ -55,9 +55,9 @@
endif
ifndef AFL_TRACE_PC
- PROGS = ../afl-clang-fast ../afl-llvm-pass.so ../afl-llvm-rt.o ../afl-llvm-rt-32.o ../afl-llvm-rt-64.o
+ PROGS = ../afl-clang-fast ../afl-llvm-pass.so ../afl-llvm-rt.o ../afl-llvm-rt-32.o ../afl-llvm-rt-64.o ../compare-transform-pass.so ../split-compares-pass.so ../split-switches-pass.so
else
- PROGS = ../afl-clang-fast ../afl-llvm-rt.o ../afl-llvm-rt-32.o ../afl-llvm-rt-64.o
+ PROGS = ../afl-clang-fast ../afl-llvm-rt.o ../afl-llvm-rt-32.o ../afl-llvm-rt-64.o ../compare-transform-pass.so ../split-compares-pass.so ../split-switches-pass.so
endif
all: test_deps $(PROGS) test_build all_done
@@ -82,6 +82,16 @@
../afl-llvm-pass.so: afl-llvm-pass.so.cc | test_deps
$(CXX) $(CLANG_CFL) -shared $< -o $@ $(CLANG_LFL)
+# laf
+../split-switches-pass.so: split-switches-pass.so.cc | test_deps
+ $(CXX) $(CLANG_CFL) -shared $< -o $@ $(CLANG_LFL)
+../compare-transform-pass.so: compare-transform-pass.so.cc | test_deps
+ $(CXX) $(CLANG_CFL) -shared $< -o $@ $(CLANG_LFL)
+../split-compares-pass.so: split-compares-pass.so.cc | test_deps
+ $(CXX) $(CLANG_CFL) -shared $< -o $@ $(CLANG_LFL)
+
+# /laf
+
../afl-llvm-rt.o: afl-llvm-rt.o.c | test_deps
$(CC) $(CFLAGS) -fPIC -c $< -o $@
diff -urN ./llvm_mode/split-compares-pass.so.cc ./llvm_mode/split-compares-pass.so.cc
--- ./llvm_mode/split-compares-pass.so.cc 1970-01-01 01:00:00.000000000 +0100
+++ ./llvm_mode/split-compares-pass.so.cc 2019-01-08 17:17:05.564960249 +0100
@@ -0,0 +1,527 @@
+/*
+ * Copyright 2016 laf-intel
+ *
+ * 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 "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/Verifier.h"
+#include "llvm/IR/Module.h"
+
+#include "llvm/IR/IRBuilder.h"
+
+using namespace llvm;
+
+namespace {
+ class SplitComparesTransform : public ModulePass {
+ public:
+ static char ID;
+ SplitComparesTransform() : ModulePass(ID) {}
+
+ bool runOnModule(Module &M) override;
+#if __clang_major__ >= 4
+ StringRef getPassName() const override {
+#else
+ const char * getPassName() const override {
+#endif
+ return "simplifies and splits ICMP instructions";
+ }
+ private:
+ bool splitCompares(Module &M, unsigned bitw);
+ bool simplifyCompares(Module &M);
+ bool simplifySignedness(Module &M);
+
+ };
+}
+
+char SplitComparesTransform::ID = 0;
+
+/* 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) {
+ 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 ) {
+ continue;
+ }
+
+ 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(bb->getTerminator()->getIterator(), 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::simplifySignedness(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 signed compares to icomps vector */
+ for (auto &F : M) {
+ 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
+ ) {
+ continue;
+ }
+
+ 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(bb->getTerminator()->getIterator(), s_op0);
+ t_op0 = new TruncInst(s_op0, Int1Ty);
+ bb->getInstList().insert(bb->getTerminator()->getIterator(), t_op0);
+
+ s_op1 = BinaryOperator::Create(Instruction::LShr, op1, ConstantInt::get(IntType, bitw - 1));
+ bb->getInstList().insert(bb->getTerminator()->getIterator(), s_op1);
+ t_op1 = new TruncInst(s_op1, Int1Ty);
+ bb->getInstList().insert(bb->getTerminator()->getIterator(), t_op1);
+
+ /* compare of the sign bits */
+ icmp_sign_bit = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, t_op0, t_op1);
+ bb->getInstList().insert(bb->getTerminator()->getIterator(), 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 positiv 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;
+}
+
+/* splits icmps of size bitw into two nested icmps with bitw/2 size each */
+bool SplitComparesTransform::splitCompares(Module &M, unsigned bitw) {
+ 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 false;
+ }
+
+ /* not supported yet */
+ if (bitw > 64) {
+ return false;
+ }
+
+ /* get all EQ, NE, UGT, and ULT icmps of width bitw. if the other two
+ * unctions were executed only these four predicates should exist */
+ for (auto &F : M) {
+ 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
+ ) {
+ continue;
+ }
+
+ 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 false;
+ }
+
+ 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 halfs 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(bb->getTerminator()->getIterator(), s_op0);
+ op0_high = new TruncInst(s_op0, NewIntType);
+ bb->getInstList().insert(bb->getTerminator()->getIterator(), op0_high);
+
+ s_op1 = BinaryOperator::Create(Instruction::LShr, op1, ConstantInt::get(OldIntType, bitw / 2));
+ bb->getInstList().insert(bb->getTerminator()->getIterator(), s_op1);
+ op1_high = new TruncInst(s_op1, NewIntType);
+ bb->getInstList().insert(bb->getTerminator()->getIterator(), op1_high);
+
+ icmp_high = CmpInst::Create(Instruction::ICmp, pred, op0_high, op1_high);
+ bb->getInstList().insert(bb->getTerminator()->getIterator(), 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);
+
+ /* dependant 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 got 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 halfs */
+ 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);
+ }
+ }
+ return true;
+}
+
+bool SplitComparesTransform::runOnModule(Module &M) {
+ int bitw = 64;
+
+ char* bitw_env = getenv("LAF_SPLIT_COMPARES_BITW");
+ if (bitw_env) {
+ bitw = atoi(bitw_env);
+ }
+
+ simplifyCompares(M);
+
+ simplifySignedness(M);
+
+ errs() << "Split-compare-pass by laf.intel@gmail.com\n";
+
+ switch (bitw) {
+ case 64:
+ errs() << "Running split-compare-pass " << 64 << "\n";
+ splitCompares(M, 64);
+
+ [[clang::fallthrough]];
+ /* fallthrough */
+ case 32:
+ errs() << "Running split-compare-pass " << 32 << "\n";
+ splitCompares(M, 32);
+
+ [[clang::fallthrough]];
+ /* fallthrough */
+ case 16:
+ errs() << "Running split-compare-pass " << 16 << "\n";
+ splitCompares(M, 16);
+ break;
+
+ default:
+ 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);
diff -urN ./llvm_mode/split-switches-pass.so.cc ./llvm_mode/split-switches-pass.so.cc
--- ./llvm_mode/split-switches-pass.so.cc 1970-01-01 01:00:00.000000000 +0100
+++ ./llvm_mode/split-switches-pass.so.cc 2019-01-08 17:17:23.073227728 +0100
@@ -0,0 +1,315 @@
+/*
+ * Copyright 2016 laf-intel
+ *
+ * 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 "llvm/ADT/Statistic.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/Pass.h"
+#include "llvm/Analysis/ValueTracking.h"
+
+#include <set>
+
+using namespace llvm;
+
+namespace {
+
+ class SplitSwitchesTransform : public ModulePass {
+
+ public:
+ static char ID;
+ SplitSwitchesTransform() : ModulePass(ID) {
+ }
+
+ bool runOnModule(Module &M) override;
+
+#if __clang_major__ >= 4
+ StringRef getPassName() const override {
+#else
+ const char * getPassName() const override {
+#endif
+ return "splits switch constructs";
+ }
+ struct CaseExpr {
+ ConstantInt* Val;
+ BasicBlock* BB;
+
+ CaseExpr(ConstantInt *val = nullptr, BasicBlock *bb = nullptr) :
+ Val(val), BB(bb) { }
+ };
+
+ typedef std::vector<CaseExpr> CaseVector;
+
+ private:
+ bool splitSwitches(Module &M);
+ bool transformCmps(Module &M, const bool processStrcmp, const bool processMemcmp);
+ BasicBlock* switchConvert(CaseVector Cases, std::vector<bool> bytesChecked,
+ BasicBlock* OrigBlock, BasicBlock* NewDefault,
+ Value* Val, unsigned level);
+ };
+
+}