diff options
| -rw-r--r-- | llvm_mode/compare-transform-pass.so.cc | 79 |
1 files changed, 53 insertions, 26 deletions
diff --git a/llvm_mode/compare-transform-pass.so.cc b/llvm_mode/compare-transform-pass.so.cc index 4879994a..4e99aafb 100644 --- a/llvm_mode/compare-transform-pass.so.cc +++ b/llvm_mode/compare-transform-pass.so.cc @@ -321,7 +321,10 @@ bool CompareTransform::transformCmps(Module &M, const bool processStrcmp, uint64_t literalLength = HasStr1 ? Str1.size() : Str2.size(); if (literalLength + 1 < ilen->getZExtValue()) continue; } - } else continue; + } else if (isMemcmp) + // this *may* supply a len greater than the constant string at + // runtime so similarly we don't want to have to handle that + continue; } calls.push_back(callInst); @@ -356,7 +359,8 @@ bool CompareTransform::transformCmps(Module &M, const bool processStrcmp, StringRef("strncmp")) || !callInst->getCalledFunction()->getName().compare( StringRef("strncasecmp")); - bool isConstSized = isSizedcmp && isa<ConstantInt>(callInst->getArgOperand(2)); + Value *sizedValue = isSizedcmp ? callInst->getArgOperand(2) : NULL; + bool isConstSized = sizedValue && isa<ConstantInt>(sizedValue); bool isCaseInsensitive = !callInst->getCalledFunction()->getName().compare( StringRef("strcasecmp")) || !callInst->getCalledFunction()->getName().compare( @@ -387,8 +391,7 @@ bool CompareTransform::transformCmps(Module &M, const bool processStrcmp, if (isConstSized) { - Value * op2 = callInst->getArgOperand(2); - constSizedLen = dyn_cast<ConstantInt>(op2)->getZExtValue(); + constSizedLen = dyn_cast<ConstantInt>(sizedValue)->getZExtValue(); } @@ -424,71 +427,95 @@ bool CompareTransform::transformCmps(Module &M, const bool processStrcmp, unrollLen = constStrLen; if (!be_quiet) - errs() << callInst->getCalledFunction()->getName() << ": len " << unrollLen + errs() << callInst->getCalledFunction()->getName() << ": unroll len " << unrollLen + << ((isSizedcmp && !isConstSized) ? ", variable n" : "") << ": " << ConstStr << "\n"; /* split before the call instruction */ BasicBlock *bb = callInst->getParent(); BasicBlock *end_bb = bb->splitBasicBlock(BasicBlock::iterator(callInst)); - BasicBlock *next_bb = + + BasicBlock *next_lenchk_bb = NULL; + if (isSizedcmp && !isConstSized) { + next_lenchk_bb = BasicBlock::Create(C, "len_check", end_bb->getParent(), end_bb); + BranchInst::Create(end_bb, next_lenchk_bb); + } + BasicBlock *next_cmp_bb = BasicBlock::Create(C, "cmp_added", end_bb->getParent(), end_bb); - BranchInst::Create(end_bb, next_bb); - PHINode *PN = PHINode::Create(Int32Ty, unrollLen + 1, "cmp_phi"); + BranchInst::Create(end_bb, next_cmp_bb); + PHINode *PN = PHINode::Create(Int32Ty, (next_lenchk_bb ? 2 : 1) * unrollLen + 1, "cmp_phi"); + #if LLVM_VERSION_MAJOR < 8 TerminatorInst *term = bb->getTerminator(); #else Instruction *term = bb->getTerminator(); #endif - BranchInst::Create(next_bb, bb); + BranchInst::Create(next_lenchk_bb ? next_lenchk_bb : next_cmp_bb, bb); term->eraseFromParent(); for (uint64_t i = 0; i < unrollLen; i++) { - BasicBlock * cur_bb = next_bb; + BasicBlock *cur_cmp_bb = next_cmp_bb, *cur_lenchk_bb = next_lenchk_bb; unsigned char c; + if (cur_lenchk_bb) { + + IRBuilder<> cur_lenchk_IRB(&*(cur_lenchk_bb->getFirstInsertionPt())); + Value *icmp = cur_lenchk_IRB.CreateICmpEQ( + sizedValue, ConstantInt::get(Int64Ty, i)); + cur_lenchk_IRB.CreateCondBr(icmp, end_bb, cur_cmp_bb); + cur_lenchk_bb->getTerminator()->eraseFromParent(); + + PN->addIncoming(ConstantInt::get(Int32Ty, 0), cur_lenchk_bb); + + } + if (isCaseInsensitive) c = (unsigned char)(tolower((int)ConstStr[i]) & 0xff); else c = (unsigned char)ConstStr[i]; - BasicBlock::iterator IP = next_bb->getFirstInsertionPt(); - IRBuilder<> IRB(&*IP); + IRBuilder<> cur_cmp_IRB(&*(cur_cmp_bb->getFirstInsertionPt())); Value *v = ConstantInt::get(Int64Ty, i); - Value *ele = IRB.CreateInBoundsGEP(VarStr, v, "empty"); - Value *load = IRB.CreateLoad(ele); + Value *ele = cur_cmp_IRB.CreateInBoundsGEP(VarStr, v, "empty"); + Value *load = cur_cmp_IRB.CreateLoad(ele); if (isCaseInsensitive) { // load >= 'A' && load <= 'Z' ? load | 0x020 : load - load = IRB.CreateZExt(load, Int32Ty); + load = cur_cmp_IRB.CreateZExt(load, Int32Ty); std::vector<Value *> args; args.push_back(load); - load = IRB.CreateCall(tolowerFn, args, "tmp"); - load = IRB.CreateTrunc(load, Int8Ty); + load = cur_cmp_IRB.CreateCall(tolowerFn, args, "tmp"); + load = cur_cmp_IRB.CreateTrunc(load, Int8Ty); } Value *isub; if (HasStr1) - isub = IRB.CreateSub(ConstantInt::get(Int8Ty, c), load); + isub = cur_cmp_IRB.CreateSub(ConstantInt::get(Int8Ty, c), load); else - isub = IRB.CreateSub(load, ConstantInt::get(Int8Ty, c)); + isub = cur_cmp_IRB.CreateSub(load, ConstantInt::get(Int8Ty, c)); - Value *sext = IRB.CreateSExt(isub, Int32Ty); - PN->addIncoming(sext, cur_bb); + Value *sext = cur_cmp_IRB.CreateSExt(isub, Int32Ty); + PN->addIncoming(sext, cur_cmp_bb); if (i < unrollLen - 1) { - next_bb = + if (cur_lenchk_bb) { + next_lenchk_bb = BasicBlock::Create(C, "len_check", end_bb->getParent(), end_bb); + BranchInst::Create(end_bb, next_lenchk_bb); + } + + next_cmp_bb = BasicBlock::Create(C, "cmp_added", end_bb->getParent(), end_bb); - BranchInst::Create(end_bb, next_bb); + BranchInst::Create(end_bb, next_cmp_bb); - Value *icmp = IRB.CreateICmpEQ(isub, ConstantInt::get(Int8Ty, 0)); - IRB.CreateCondBr(icmp, next_bb, end_bb); - cur_bb->getTerminator()->eraseFromParent(); + Value *icmp = cur_cmp_IRB.CreateICmpEQ(isub, ConstantInt::get(Int8Ty, 0)); + cur_cmp_IRB.CreateCondBr(icmp, next_lenchk_bb ? next_lenchk_bb : next_cmp_bb, end_bb); + cur_cmp_bb->getTerminator()->eraseFromParent(); } else { |