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Diffstat (limited to 'llvm/lib/VMCore/AutoUpgrade.cpp')
-rw-r--r-- | llvm/lib/VMCore/AutoUpgrade.cpp | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/llvm/lib/VMCore/AutoUpgrade.cpp b/llvm/lib/VMCore/AutoUpgrade.cpp new file mode 100644 index 00000000000..b56fe70235e --- /dev/null +++ b/llvm/lib/VMCore/AutoUpgrade.cpp @@ -0,0 +1,197 @@ +//===-- AutoUpgrade.cpp - Implement auto-upgrade helper functions ---------===// +// +// The LLVM Compiler Infrastructure +// +// This file was developed by Chandler Carruth and is distributed under the +// University of Illinois Open Source License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements the auto-upgrade helper functions +// +//===----------------------------------------------------------------------===// + +#include "llvm/AutoUpgrade.h" +#include "llvm/Function.h" +#include "llvm/Module.h" +#include "llvm/Instructions.h" +#include "llvm/ParameterAttributes.h" +#include "llvm/Intrinsics.h" +using namespace llvm; + + +Function* llvm::UpgradeIntrinsicFunction(Function *F) { + assert(F && "Illegal to upgrade a non-existent Function."); + + // Get the Function's name. + const std::string& Name = F->getName(); + + // Convenience + const FunctionType *FTy = F->getFunctionType(); + + // Quickly eliminate it, if it's not a candidate. + if (Name.length() <= 8 || Name[0] != 'l' || Name[1] != 'l' || + Name[2] != 'v' || Name[3] != 'm' || Name[4] != '.') + return 0; + + Module *M = F->getParent(); + switch (Name[5]) { + default: break; + case 'b': + // This upgrades the name of the llvm.bswap intrinsic function to only use + // a single type name for overloading. We only care about the old format + // 'llvm.bswap.i*.i*', so check for 'bswap.' and then for there being + // a '.' after 'bswap.' + if (Name.compare(5,6,"bswap.",6) == 0) { + std::string::size_type delim = Name.find('.',11); + + if (delim != std::string::npos) { + // Construct the new name as 'llvm.bswap' + '.i*' + F->setName(Name.substr(0,10)+Name.substr(delim)); + return F; + } + } + break; + + case 'c': + // We only want to fix the 'llvm.ct*' intrinsics which do not have the + // correct return type, so we check for the name, and then check if the + // return type does not match the parameter type. + if ( (Name.compare(5,5,"ctpop",5) == 0 || + Name.compare(5,4,"ctlz",4) == 0 || + Name.compare(5,4,"cttz",4) == 0) && + FTy->getReturnType() != FTy->getParamType(0)) { + // We first need to change the name of the old (bad) intrinsic, because + // its type is incorrect, but we cannot overload that name. We + // arbitrarily unique it here allowing us to construct a correctly named + // and typed function below. + F->setName(""); + + // Now construct the new intrinsic with the correct name and type. We + // leave the old function around in order to query its type, whatever it + // may be, and correctly convert up to the new type. + return cast<Function>(M->getOrInsertFunction(Name, + FTy->getParamType(0), + FTy->getParamType(0), + (Type *)0)); + } + break; + + case 'p': + // This upgrades the llvm.part.select overloaded intrinsic names to only + // use one type specifier in the name. We only care about the old format + // 'llvm.part.select.i*.i*', and solve as above with bswap. + if (Name.compare(5,12,"part.select.",12) == 0) { + std::string::size_type delim = Name.find('.',17); + + if (delim != std::string::npos) { + // Construct a new name as 'llvm.part.select' + '.i*' + F->setName(Name.substr(0,16)+Name.substr(delim)); + return F; + } + break; + } + + // This upgrades the llvm.part.set intrinsics similarly as above, however + // we care about 'llvm.part.set.i*.i*.i*', but only the first two types + // must match. There is an additional type specifier after these two + // matching types that we must retain when upgrading. Thus, we require + // finding 2 periods, not just one, after the intrinsic name. + if (Name.compare(5,9,"part.set.",9) == 0) { + std::string::size_type delim = Name.find('.',14); + + if (delim != std::string::npos && + Name.find('.',delim+1) != std::string::npos) { + // Construct a new name as 'llvm.part.select' + '.i*.i*' + F->setName(Name.substr(0,13)+Name.substr(delim)); + return F; + } + break; + } + + break; + } + + // This may not belong here. This function is effectively being overloaded + // to both detect an intrinsic which needs upgrading, and to provide the + // upgraded form of the intrinsic. We should perhaps have two separate + // functions for this. + return 0; +} + +// UpgradeIntrinsicCall - Upgrade a call to an old intrinsic to be a call the +// upgraded intrinsic. All argument and return casting must be provided in +// order to seamlessly integrate with existing context. +void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) { + assert(NewFn && "Cannot upgrade an intrinsic call without a new function."); + + Function *F = CI->getCalledFunction(); + assert(F && "CallInst has no function associated with it."); + + const FunctionType *FTy = F->getFunctionType(); + const FunctionType *NewFnTy = NewFn->getFunctionType(); + + switch(NewFn->getIntrinsicID()) { + default: assert(0 && "Unknown function for CallInst upgrade."); + case Intrinsic::ctlz: + case Intrinsic::ctpop: + case Intrinsic::cttz: + // Build a small vector of the 1..(N-1) operands, which are the + // parameters. + SmallVector<Value*, 8> Operands(CI->op_begin()+1, CI->op_end()); + + // Construct a new CallInst + CallInst *NewCI = new CallInst(NewFn, Operands.begin(), Operands.end(), + "upgraded."+CI->getName(), CI); + NewCI->setTailCall(CI->isTailCall()); + NewCI->setCallingConv(CI->getCallingConv()); + + // Handle any uses of the old CallInst. + if (!CI->use_empty()) { + // Check for sign extend parameter attributes on the return values. + bool SrcSExt = NewFnTy->getParamAttrs() && + NewFnTy->getParamAttrs()->paramHasAttr(0,ParamAttr::SExt); + bool DestSExt = FTy->getParamAttrs() && + FTy->getParamAttrs()->paramHasAttr(0,ParamAttr::SExt); + + // Construct an appropriate cast from the new return type to the old. + CastInst *RetCast = CastInst::create( + CastInst::getCastOpcode(NewCI, SrcSExt, + F->getReturnType(), + DestSExt), + NewCI, F->getReturnType(), + NewCI->getName(), CI); + NewCI->moveBefore(RetCast); + + // Replace all uses of the old call with the new cast which has the + // correct type. + CI->replaceAllUsesWith(RetCast); + } + + // Clean up the old call now that it has been completely upgraded. + CI->eraseFromParent(); + break; + } +} + +// This tests each Function to determine if it needs upgrading. When we find +// one we are interested in, we then upgrade all calls to reflect the new +// function. +void llvm::UpgradeCallsToIntrinsic(Function* F) { + assert(F && "Illegal attempt to upgrade a non-existent intrinsic."); + + // Upgrade the function and check if it is a totaly new function. + if (Function* NewFn = UpgradeIntrinsicFunction(F)) { + if (NewFn != F) { + // Replace all uses to the old function with the new one if necessary. + for (Value::use_iterator UI = F->use_begin(), UE = F->use_end(); + UI != UE; ) { + if (CallInst* CI = dyn_cast<CallInst>(*UI++)) + UpgradeIntrinsicCall(CI, NewFn); + } + // Remove old function, no longer used, from the module. + F->eraseFromParent(); + } + } +} + |