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+//===-- 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();
+ }
+ }
+}
+
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