//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/Pass.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/Debug.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/Compiler.h"
+#include <map>
#include <set>
using namespace llvm;
std::multimap<Function*, CallSite> CallSites;
public:
+ static char ID; // Pass identification, replacement for typeid
+ DAE() : ModulePass((intptr_t)&ID) {}
bool runOnModule(Module &M);
virtual bool ShouldHackArguments() const { return false; }
void RemoveDeadArgumentsFromFunction(Function *F);
};
+ char DAE::ID = 0;
RegisterPass<DAE> X("deadargelim", "Dead Argument Elimination");
/// DAH - DeadArgumentHacking pass - Same as dead argument elimination, but
/// deletes arguments to functions which are external. This is only for use
/// by bugpoint.
struct DAH : public DAE {
+ static char ID;
virtual bool ShouldHackArguments() const { return true; }
};
+ char DAH::ID = 0;
RegisterPass<DAH> Y("deadarghaX0r",
"Dead Argument Hacking (BUGPOINT USE ONLY; DO NOT USE)");
}
bool DAE::DeleteDeadVarargs(Function &Fn) {
assert(Fn.getFunctionType()->isVarArg() && "Function isn't varargs!");
if (Fn.isDeclaration() || !Fn.hasInternalLinkage()) return false;
-
+
// Ensure that the function is only directly called.
for (Value::use_iterator I = Fn.use_begin(), E = Fn.use_end(); I != E; ++I) {
// If this use is anything other than a call site, give up.
CallSite CS = CallSite::get(*I);
Instruction *TheCall = CS.getInstruction();
if (!TheCall) return false; // Not a direct call site?
-
+
// The addr of this function is passed to the call.
if (I.getOperandNo() != 0) return false;
}
-
+
// Okay, we know we can transform this function if safe. Scan its body
// looking for calls to llvm.vastart.
for (Function::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
}
}
}
-
+
// If we get here, there are no calls to llvm.vastart in the function body,
// remove the "..." and adjust all the calls.
-
+
// Start by computing a new prototype for the function, which is the same as
// the old function, but has fewer arguments.
const FunctionType *FTy = Fn.getFunctionType();
std::vector<const Type*> Params(FTy->param_begin(), FTy->param_end());
FunctionType *NFTy = FunctionType::get(FTy->getReturnType(), Params, false);
unsigned NumArgs = Params.size();
-
+
// Create the new function body and insert it into the module...
- std::string Name = Fn.getName(); Fn.setName("");
- Function *NF = new Function(NFTy, Fn.getLinkage(), Name);
+ Function *NF = Function::Create(NFTy, Fn.getLinkage());
NF->setCallingConv(Fn.getCallingConv());
+ NF->setParamAttrs(Fn.getParamAttrs());
+ if (Fn.hasCollector())
+ NF->setCollector(Fn.getCollector());
Fn.getParent()->getFunctionList().insert(&Fn, NF);
-
+ NF->takeName(&Fn);
+
// Loop over all of the callers of the function, transforming the call sites
// to pass in a smaller number of arguments into the new function.
//
while (!Fn.use_empty()) {
CallSite CS = CallSite::get(Fn.use_back());
Instruction *Call = CS.getInstruction();
-
- // Loop over the operands, dropping extraneous ones at the end of the list.
+
+ // Pass all the same arguments.
Args.assign(CS.arg_begin(), CS.arg_begin()+NumArgs);
-
+
+ // Drop any attributes that were on the vararg arguments.
+ PAListPtr PAL = CS.getParamAttrs();
+ if (!PAL.isEmpty() && PAL.getSlot(PAL.getNumSlots() - 1).Index > NumArgs) {
+ SmallVector<ParamAttrsWithIndex, 8> ParamAttrsVec;
+ for (unsigned i = 0; PAL.getSlot(i).Index <= NumArgs; ++i)
+ ParamAttrsVec.push_back(PAL.getSlot(i));
+ PAL = PAListPtr::get(ParamAttrsVec.begin(), ParamAttrsVec.end());
+ }
+
Instruction *New;
if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
- New = new InvokeInst(NF, II->getNormalDest(), II->getUnwindDest(),
- Args, "", Call);
+ New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
+ Args.begin(), Args.end(), "", Call);
cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
+ cast<InvokeInst>(New)->setParamAttrs(PAL);
} else {
- New = new CallInst(NF, Args, "", Call);
+ New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call);
cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
+ cast<CallInst>(New)->setParamAttrs(PAL);
if (cast<CallInst>(Call)->isTailCall())
cast<CallInst>(New)->setTailCall();
}
Args.clear();
-
+
if (!Call->use_empty())
- Call->replaceAllUsesWith(Constant::getNullValue(Call->getType()));
-
- if (Call->hasName()) {
- std::string Name = Call->getName();
- Call->setName("");
- New->setName(Name);
- }
-
+ Call->replaceAllUsesWith(New);
+
+ New->takeName(Call);
+
// Finally, remove the old call from the program, reducing the use-count of
// F.
- Call->getParent()->getInstList().erase(Call);
+ Call->eraseFromParent();
}
-
+
// Since we have now created the new function, splice the body of the old
// function right into the new function, leaving the old rotting hulk of the
// function empty.
NF->getBasicBlockList().splice(NF->begin(), Fn.getBasicBlockList());
-
+
// Loop over the argument list, transfering uses of the old arguments over to
// the new arguments, also transfering over the names as well. While we're at
// it, remove the dead arguments from the DeadArguments list.
I2 = NF->arg_begin(); I != E; ++I, ++I2) {
// Move the name and users over to the new version.
I->replaceAllUsesWith(I2);
- I2->setName(I->getName());
+ I2->takeName(I);
}
-
+
// Finally, nuke the old function.
Fn.eraseFromParent();
return true;
// (used in a computation), MaybeLive (only passed as an argument to a call), or
// Dead (not used).
DAE::Liveness DAE::getArgumentLiveness(const Argument &A) {
- const FunctionType *FTy = A.getParent()->getFunctionType();
+ const Function *F = A.getParent();
// If this is the return value of a struct function, it's not really dead.
- if (FTy->isStructReturn() && &*A.getParent()->arg_begin() == &A)
+ if (F->hasStructRetAttr() && &*(F->arg_begin()) == &A)
return Live;
if (A.use_empty()) // First check, directly dead?
Liveness RetValLiveness = F.getReturnType() == Type::VoidTy ? Live : Dead;
if (!F.hasInternalLinkage() &&
- (!ShouldHackArguments() || F.getIntrinsicID()))
+ (!ShouldHackArguments() || F.isIntrinsic()))
FunctionIntrinsicallyLive = true;
else
for (Value::use_iterator I = F.use_begin(), E = F.use_end(); I != E; ++I) {
const FunctionType *FTy = F->getFunctionType();
std::vector<const Type*> Params;
- for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
- if (!DeadArguments.count(I))
- Params.push_back(I->getType());
+ // Set up to build a new list of parameter attributes
+ SmallVector<ParamAttrsWithIndex, 8> ParamAttrsVec;
+ const PAListPtr &PAL = F->getParamAttrs();
+
+ // The existing function return attributes.
+ ParameterAttributes RAttrs = PAL.getParamAttrs(0);
+ // Make the function return void if the return value is dead.
const Type *RetTy = FTy->getReturnType();
if (DeadRetVal.count(F)) {
RetTy = Type::VoidTy;
+ RAttrs &= ~ParamAttr::typeIncompatible(RetTy);
DeadRetVal.erase(F);
}
+ if (RAttrs)
+ ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, RAttrs));
+
+ // Construct the new parameter list from non-dead arguments. Also construct
+ // a new set of parameter attributes to correspond.
+ unsigned index = 1;
+ for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E;
+ ++I, ++index)
+ if (!DeadArguments.count(I)) {
+ Params.push_back(I->getType());
+
+ if (ParameterAttributes Attrs = PAL.getParamAttrs(index))
+ ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Params.size(), Attrs));
+ }
+
+ // Reconstruct the ParamAttrsList based on the vector we constructed.
+ PAListPtr NewPAL = PAListPtr::get(ParamAttrsVec.begin(), ParamAttrsVec.end());
+
// Work around LLVM bug PR56: the CWriter cannot emit varargs functions which
// have zero fixed arguments.
//
Params.push_back(Type::Int32Ty);
}
+ // Create the new function type based on the recomputed parameters.
FunctionType *NFTy = FunctionType::get(RetTy, Params, FTy->isVarArg());
// Create the new function body and insert it into the module...
- std::string Name = F->getName(); F->setName("");
- Function *NF = new Function(NFTy, F->getLinkage(), Name);
+ Function *NF = Function::Create(NFTy, F->getLinkage());
NF->setCallingConv(F->getCallingConv());
+ NF->setParamAttrs(NewPAL);
+ if (F->hasCollector())
+ NF->setCollector(F->getCollector());
F->getParent()->getFunctionList().insert(F, NF);
+ NF->takeName(F);
// Loop over all of the callers of the function, transforming the call sites
// to pass in a smaller number of arguments into the new function.
while (!F->use_empty()) {
CallSite CS = CallSite::get(F->use_back());
Instruction *Call = CS.getInstruction();
+ ParamAttrsVec.clear();
+ const PAListPtr &CallPAL = CS.getParamAttrs();
+
+ // The call return attributes.
+ ParameterAttributes RAttrs = CallPAL.getParamAttrs(0);
+ // Adjust in case the function was changed to return void.
+ RAttrs &= ~ParamAttr::typeIncompatible(NF->getReturnType());
+ if (RAttrs)
+ ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, RAttrs));
// Loop over the operands, deleting dead ones...
CallSite::arg_iterator AI = CS.arg_begin();
+ index = 1;
for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end();
- I != E; ++I, ++AI)
- if (!DeadArguments.count(I)) // Remove operands for dead arguments
+ I != E; ++I, ++AI, ++index)
+ if (!DeadArguments.count(I)) { // Remove operands for dead arguments
Args.push_back(*AI);
+ if (ParameterAttributes Attrs = CallPAL.getParamAttrs(index))
+ ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Args.size(), Attrs));
+ }
if (ExtraArgHack)
Args.push_back(UndefValue::get(Type::Int32Ty));
- // Push any varargs arguments on the list
- for (; AI != CS.arg_end(); ++AI)
+ // Push any varargs arguments on the list. Don't forget their attributes.
+ for (; AI != CS.arg_end(); ++AI) {
Args.push_back(*AI);
+ if (ParameterAttributes Attrs = CallPAL.getParamAttrs(index++))
+ ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Args.size(), Attrs));
+ }
+
+ // Reconstruct the ParamAttrsList based on the vector we constructed.
+ PAListPtr NewCallPAL = PAListPtr::get(ParamAttrsVec.begin(),
+ ParamAttrsVec.end());
Instruction *New;
if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
- New = new InvokeInst(NF, II->getNormalDest(), II->getUnwindDest(),
- Args, "", Call);
+ New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
+ Args.begin(), Args.end(), "", Call);
cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
+ cast<InvokeInst>(New)->setParamAttrs(NewCallPAL);
} else {
- New = new CallInst(NF, Args, "", Call);
+ New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call);
cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
+ cast<CallInst>(New)->setParamAttrs(NewCallPAL);
if (cast<CallInst>(Call)->isTailCall())
cast<CallInst>(New)->setTailCall();
}
Call->replaceAllUsesWith(Constant::getNullValue(Call->getType()));
else {
Call->replaceAllUsesWith(New);
- std::string Name = Call->getName();
- Call->setName("");
- New->setName(Name);
+ New->takeName(Call);
}
}
// If this is a live argument, move the name and users over to the new
// version.
I->replaceAllUsesWith(I2);
- I2->setName(I->getName());
+ I2->takeName(I);
++I2;
} else {
// If this argument is dead, replace any uses of it with null constants
if (F->getReturnType() != NF->getReturnType())
for (Function::iterator BB = NF->begin(), E = NF->end(); BB != E; ++BB)
if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
- new ReturnInst(0, RI);
+ ReturnInst::Create(0, RI);
BB->getInstList().erase(RI);
}
}
bool DAE::runOnModule(Module &M) {
- // First phase: loop through the module, determining which arguments are live.
- // We assume all arguments are dead unless proven otherwise (allowing us to
- // determine that dead arguments passed into recursive functions are dead).
- //
- DOUT << "DAE - Determining liveness\n";
+ bool Changed = false;
+ // First pass: Do a simple check to see if any functions can have their "..."
+ // removed. We can do this if they never call va_start. This loop cannot be
+ // fused with the next loop, because deleting a function invalidates
+ // information computed while surveying other functions.
+ DOUT << "DAE - Deleting dead varargs\n";
for (Module::iterator I = M.begin(), E = M.end(); I != E; ) {
Function &F = *I++;
if (F.getFunctionType()->isVarArg())
- if (DeleteDeadVarargs(F))
- continue;
-
- SurveyFunction(F);
+ Changed |= DeleteDeadVarargs(F);
}
+
+ // Second phase:loop through the module, determining which arguments are live.
+ // We assume all arguments are dead unless proven otherwise (allowing us to
+ // determine that dead arguments passed into recursive functions are dead).
+ //
+ DOUT << "DAE - Determining liveness\n";
+ for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
+ SurveyFunction(*I);
// Loop over the instructions to inspect, propagating liveness among arguments
// and return values which are MaybeLive.
-
while (!InstructionsToInspect.empty()) {
Instruction *I = InstructionsToInspect.back();
InstructionsToInspect.pop_back();
// to do.
if (MaybeLiveArguments.empty() && DeadArguments.empty() &&
MaybeLiveRetVal.empty() && DeadRetVal.empty())
- return false;
+ return Changed;
// Otherwise, compact into one set, and start eliminating the arguments from
// the functions.
projects / oota-llvm.git / blobdiff