#include "llvm/DerivedTypes.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
+#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
-#include "llvm/Support/Compiler.h"
#include <map>
#include <set>
using namespace llvm;
namespace {
/// DAE - The dead argument elimination pass.
///
- class VISIBILITY_HIDDEN DAE : public ModulePass {
+ class DAE : public ModulePass {
public:
/// Struct that represents (part of) either a return value or a function
/// argument. Used so that arguments and return values can be used
- /// interchangably. Idx == -1 means the entire return value, while other
- /// indices mean the corresponding element in the struct return type (if
- /// any).
+ /// interchangably.
struct RetOrArg {
- RetOrArg(const Function* F, signed Idx, bool IsArg) : F(F), Idx(Idx),
+ RetOrArg(const Function *F, unsigned Idx, bool IsArg) : F(F), Idx(Idx),
IsArg(IsArg) {}
const Function *F;
- signed Idx;
+ unsigned Idx;
bool IsArg;
/// Make RetOrArg comparable, so we can put it into a map.
}
std::string getDescription() const {
- return std::string((!IsArg && Idx != -1 ? "partial " : ""))
- + (IsArg ? "argument #" : "return value")
- + (!IsArg && Idx == -1 ? "" : " #" + utostr(Idx))
- + " of function " + F->getName();
+ return std::string((IsArg ? "Argument #" : "Return value #"))
+ + utostr(Idx) + " of function " + F->getNameStr();
}
};
enum Liveness { Live, MaybeLive };
/// Convenience wrapper
- RetOrArg CreateRet(const Function *F, signed Idx) {
+ RetOrArg CreateRet(const Function *F, unsigned Idx) {
return RetOrArg(F, Idx, false);
}
/// Convenience wrapper
- RetOrArg CreateArg(const Function *F, signed Idx) {
+ RetOrArg CreateArg(const Function *F, unsigned Idx) {
return RetOrArg(F, Idx, true);
}
typedef SmallVector<RetOrArg, 5> UseVector;
+ protected:
+ // DAH uses this to specify a different ID.
+ explicit DAE(void *ID) : ModulePass(ID) {}
+
public:
static char ID; // Pass identification, replacement for typeid
- DAE() : ModulePass((intptr_t)&ID) {}
+ DAE() : ModulePass(&ID) {}
+
bool runOnModule(Module &M);
virtual bool ShouldHackArguments() const { return false; }
private:
Liveness MarkIfNotLive(RetOrArg Use, UseVector &MaybeLiveUses);
- Liveness SurveyUse(Value::use_iterator U, UseVector &MaybeLiveUses,
- signed RetValNum = -1);
- Liveness SurveyUses(Value *V, UseVector &MaybeLiveUses);
+ Liveness SurveyUse(Value::const_use_iterator U, UseVector &MaybeLiveUses,
+ unsigned RetValNum = 0);
+ Liveness SurveyUses(const Value *V, UseVector &MaybeLiveUses);
- void SurveyFunction(Function &F);
+ void SurveyFunction(const Function &F);
void MarkValue(const RetOrArg &RA, Liveness L,
const UseVector &MaybeLiveUses);
void MarkLive(const RetOrArg &RA);
char DAE::ID = 0;
-static RegisterPass<DAE>
-X("deadargelim", "Dead Argument Elimination");
+INITIALIZE_PASS(DAE, "deadargelim", "Dead Argument Elimination", false, false);
namespace {
/// DAH - DeadArgumentHacking pass - Same as dead argument elimination, but
/// by bugpoint.
struct DAH : public DAE {
static char ID;
+ DAH() : DAE(&ID) {}
+
virtual bool ShouldHackArguments() const { return true; }
};
}
char DAH::ID = 0;
-static RegisterPass<DAH>
-Y("deadarghaX0r", "Dead Argument Hacking (BUGPOINT USE ONLY; DO NOT USE)");
+INITIALIZE_PASS(DAH, "deadarghaX0r",
+ "Dead Argument Hacking (BUGPOINT USE ONLY; DO NOT USE)",
+ false, false);
/// createDeadArgEliminationPass - This pass removes arguments from functions
/// which are not used by the body of the function.
/// llvm.vastart is never called, the varargs list is dead for the function.
bool DAE::DeleteDeadVarargs(Function &Fn) {
assert(Fn.getFunctionType()->isVarArg() && "Function isn't varargs!");
- if (Fn.isDeclaration() || !Fn.hasInternalLinkage()) return false;
+ if (Fn.isDeclaration() || !Fn.hasLocalLinkage()) 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;
- }
+ if (Fn.hasAddressTaken())
+ return false;
// Okay, we know we can transform this function if safe. Scan its body
// looking for calls to llvm.vastart.
// Start by computing a new prototype for the function, which is the same as
// the old function, but doesn't have isVarArg set.
const FunctionType *FTy = Fn.getFunctionType();
+
std::vector<const Type*> Params(FTy->param_begin(), FTy->param_end());
- FunctionType *NFTy = FunctionType::get(FTy->getReturnType(), Params, false);
+ FunctionType *NFTy = FunctionType::get(FTy->getReturnType(),
+ Params, false);
unsigned NumArgs = Params.size();
// Create the new function body and insert it into the module...
Args.assign(CS.arg_begin(), CS.arg_begin()+NumArgs);
// Drop any attributes that were on the vararg arguments.
- PAListPtr PAL = CS.getParamAttrs();
+ AttrListPtr PAL = CS.getAttributes();
if (!PAL.isEmpty() && PAL.getSlot(PAL.getNumSlots() - 1).Index > NumArgs) {
- SmallVector<ParamAttrsWithIndex, 8> ParamAttrsVec;
+ SmallVector<AttributeWithIndex, 8> AttributesVec;
for (unsigned i = 0; PAL.getSlot(i).Index <= NumArgs; ++i)
- ParamAttrsVec.push_back(PAL.getSlot(i));
- PAL = PAListPtr::get(ParamAttrsVec.begin(), ParamAttrsVec.end());
+ AttributesVec.push_back(PAL.getSlot(i));
+ if (Attributes FnAttrs = PAL.getFnAttributes())
+ AttributesVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
+ PAL = AttrListPtr::get(AttributesVec.begin(), AttributesVec.end());
}
Instruction *New;
New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
Args.begin(), Args.end(), "", Call);
cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
- cast<InvokeInst>(New)->setParamAttrs(PAL);
+ cast<InvokeInst>(New)->setAttributes(PAL);
} else {
New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call);
cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
- cast<CallInst>(New)->setParamAttrs(PAL);
+ cast<CallInst>(New)->setAttributes(PAL);
if (cast<CallInst>(Call)->isTailCall())
cast<CallInst>(New)->setTailCall();
}
+ New->setDebugLoc(Call->getDebugLoc());
+
Args.clear();
if (!Call->use_empty())
return true;
}
+/// Convenience function that returns the number of return values. It returns 0
+/// for void functions and 1 for functions not returning a struct. It returns
+/// the number of struct elements for functions returning a struct.
+static unsigned NumRetVals(const Function *F) {
+ if (F->getReturnType()->isVoidTy())
+ return 0;
+ else if (const StructType *STy = dyn_cast<StructType>(F->getReturnType()))
+ return STy->getNumElements();
+ else
+ return 1;
+}
+
/// MarkIfNotLive - This checks Use for liveness in LiveValues. If Use is not
/// live, it adds Use to the MaybeLiveUses argument. Returns the determined
/// liveness of Use.
return MaybeLive;
}
+
/// SurveyUse - This looks at a single use of an argument or return value
/// and determines if it should be alive or not. Adds this use to MaybeLiveUses
-/// if it causes the used value to become MaybeAlive.
+/// if it causes the used value to become MaybeLive.
///
/// RetValNum is the return value number to use when this use is used in a
/// return instruction. This is used in the recursion, you should always leave
-/// it at -1.
-DAE::Liveness DAE::SurveyUse(Value::use_iterator U, UseVector &MaybeLiveUses,
- signed RetValNum) {
- Value *V = *U;
- if (ReturnInst *RI = dyn_cast<ReturnInst>(V)) {
+/// it at 0.
+DAE::Liveness DAE::SurveyUse(Value::const_use_iterator U,
+ UseVector &MaybeLiveUses, unsigned RetValNum) {
+ const User *V = *U;
+ if (const ReturnInst *RI = dyn_cast<ReturnInst>(V)) {
// The value is returned from a function. It's only live when the
// function's return value is live. We use RetValNum here, for the case
// that U is really a use of an insertvalue instruction that uses the
// We might be live, depending on the liveness of Use.
return MarkIfNotLive(Use, MaybeLiveUses);
}
- if (InsertValueInst *IV = dyn_cast<InsertValueInst>(V)) {
+ if (const InsertValueInst *IV = dyn_cast<InsertValueInst>(V)) {
if (U.getOperandNo() != InsertValueInst::getAggregateOperandIndex()
&& IV->hasIndices())
// The use we are examining is inserted into an aggregate. Our liveness
// we don't change RetValNum, but do survey all our uses.
Liveness Result = MaybeLive;
- for (Value::use_iterator I = IV->use_begin(),
+ for (Value::const_use_iterator I = IV->use_begin(),
E = V->use_end(); I != E; ++I) {
Result = SurveyUse(I, MaybeLiveUses, RetValNum);
if (Result == Live)
}
return Result;
}
- CallSite CS = CallSite::get(V);
- if (CS.getInstruction()) {
- Function *F = CS.getCalledFunction();
+
+ if (ImmutableCallSite CS = V) {
+ const Function *F = CS.getCalledFunction();
if (F) {
// Used in a direct call.
-
+
// Find the argument number. We know for sure that this use is an
// argument, since if it was the function argument this would be an
// indirect call and the we know can't be looking at a value of the
// label type (for the invoke instruction).
- unsigned ArgNo = CS.getArgumentNo(U.getOperandNo());
+ unsigned ArgNo = CS.getArgumentNo(U);
if (ArgNo >= F->getFunctionType()->getNumParams())
// The value is passed in through a vararg! Must be live.
return Live;
- assert(CS.getArgument(ArgNo)
- == CS.getInstruction()->getOperand(U.getOperandNo())
+ assert(CS.getArgument(ArgNo)
+ == CS->getOperand(U.getOperandNo())
&& "Argument is not where we expected it");
// Value passed to a normal call. It's only live when the corresponding
/// Adds all uses that cause the result to be MaybeLive to MaybeLiveRetUses. If
/// the result is Live, MaybeLiveUses might be modified but its content should
/// be ignored (since it might not be complete).
-DAE::Liveness DAE::SurveyUses(Value *V, UseVector &MaybeLiveUses) {
+DAE::Liveness DAE::SurveyUses(const Value *V, UseVector &MaybeLiveUses) {
// Assume it's dead (which will only hold if there are no uses at all..).
Liveness Result = MaybeLive;
// Check each use.
- for (Value::use_iterator I = V->use_begin(),
+ for (Value::const_use_iterator I = V->use_begin(),
E = V->use_end(); I != E; ++I) {
Result = SurveyUse(I, MaybeLiveUses);
if (Result == Live)
// We consider arguments of non-internal functions to be intrinsically alive as
// well as arguments to functions which have their "address taken".
//
-void DAE::SurveyFunction(Function &F) {
- const StructType *STy = dyn_cast<StructType>(F.getFunctionType()->getReturnType());
- // Store the number of partial return values, which we only have if the return
- // type is a struct.
- unsigned PartialRetVals = (STy ? STy->getNumElements() : 0);
+void DAE::SurveyFunction(const Function &F) {
+ unsigned RetCount = NumRetVals(&F);
// Assume all return values are dead
typedef SmallVector<Liveness, 5> RetVals;
- // Allocate one slot for the entire return value (index 0) and one for each
- // partial return value.
- RetVals RetValLiveness(PartialRetVals + 1, MaybeLive);
+ RetVals RetValLiveness(RetCount, MaybeLive);
typedef SmallVector<UseVector, 5> RetUses;
// These vectors map each return value to the uses that make it MaybeLive, so
// we can add those to the Uses map if the return value really turns out to be
- // MaybeLive.
- // Allocate one slot for the entire return value (index 0) and one for each
- // partial return value.
- RetUses MaybeLiveRetUses(PartialRetVals + 1);
+ // MaybeLive. Initialized to a list of RetCount empty lists.
+ RetUses MaybeLiveRetUses(RetCount);
- for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
- if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator()))
+ for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
+ if (const ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator()))
if (RI->getNumOperands() != 0 && RI->getOperand(0)->getType()
!= F.getFunctionType()->getReturnType()) {
// We don't support old style multiple return values.
return;
}
- if (!F.hasInternalLinkage() && (!ShouldHackArguments() || F.isIntrinsic())) {
+ if (!F.hasLocalLinkage() && (!ShouldHackArguments() || F.isIntrinsic())) {
MarkLive(F);
return;
}
- DOUT << "DAE - Inspecting callers for fn: " << F.getName() << "\n";
+ DEBUG(dbgs() << "DAE - Inspecting callers for fn: " << F.getName() << "\n");
+ // Keep track of the number of live retvals, so we can skip checks once all
+ // of them turn out to be live.
+ unsigned NumLiveRetVals = 0;
+ const Type *STy = dyn_cast<StructType>(F.getReturnType());
// Loop all uses of the function.
- for (Value::use_iterator I = F.use_begin(), E = F.use_end(); I != E; ++I) {
+ for (Value::const_use_iterator I = F.use_begin(), E = F.use_end();
+ I != E; ++I) {
// If the function is PASSED IN as an argument, its address has been
// taken.
- if (I.getOperandNo() != 0) {
+ ImmutableCallSite CS(*I);
+ if (!CS || !CS.isCallee(I)) {
MarkLive(F);
return;
}
// If this use is anything other than a call site, the function is alive.
- CallSite CS = CallSite::get(*I);
- Instruction *TheCall = CS.getInstruction();
+ const Instruction *TheCall = CS.getInstruction();
if (!TheCall) { // Not a direct call site?
MarkLive(F);
return;
// If we end up here, we are looking at a direct call to our function.
// Now, check how our return value(s) is/are used in this caller. Don't
- // bother checking return values if the entire value is live already.
- if (RetValLiveness[0] != Live) {
- // Check all uses of the return value.
- for (Value::use_iterator I = TheCall->use_begin(),
- E = TheCall->use_end(); I != E; ++I) {
- ExtractValueInst *Ext = dyn_cast<ExtractValueInst>(*I);
- if (Ext && Ext->hasIndices()) {
- // This use uses a part of our return value, survey the uses of
- // that part and store the results for this index only.
- unsigned Idx = *Ext->idx_begin();
- // + 1 to skip the "entire retval" index (0)
- Liveness &IsLive = RetValLiveness[Idx + 1];
- if (IsLive != Live) {
- // Don't bother checking if this retval was already live
- // Survey all uses of the extractvalue
- // + 1 to skip the "entire retval" index (0)
- IsLive = SurveyUses(Ext, MaybeLiveRetUses[Idx + 1]);
- }
- } else {
- // Survey this use
- RetValLiveness[0] = SurveyUse(I, MaybeLiveRetUses[0]);
- if (RetValLiveness[0] == Live)
+ // bother checking return values if all of them are live already.
+ if (NumLiveRetVals != RetCount) {
+ if (STy) {
+ // Check all uses of the return value.
+ for (Value::const_use_iterator I = TheCall->use_begin(),
+ E = TheCall->use_end(); I != E; ++I) {
+ const ExtractValueInst *Ext = dyn_cast<ExtractValueInst>(*I);
+ if (Ext && Ext->hasIndices()) {
+ // This use uses a part of our return value, survey the uses of
+ // that part and store the results for this index only.
+ unsigned Idx = *Ext->idx_begin();
+ if (RetValLiveness[Idx] != Live) {
+ RetValLiveness[Idx] = SurveyUses(Ext, MaybeLiveRetUses[Idx]);
+ if (RetValLiveness[Idx] == Live)
+ NumLiveRetVals++;
+ }
+ } else {
+ // Used by something else than extractvalue. Mark all return
+ // values as live.
+ for (unsigned i = 0; i != RetCount; ++i )
+ RetValLiveness[i] = Live;
+ NumLiveRetVals = RetCount;
break;
+ }
}
+ } else {
+ // Single return value
+ RetValLiveness[0] = SurveyUses(TheCall, MaybeLiveRetUses[0]);
+ if (RetValLiveness[0] == Live)
+ NumLiveRetVals = RetCount;
}
}
}
// Now we've inspected all callers, record the liveness of our return values.
- MarkValue(CreateRet(&F, -1), RetValLiveness[0], MaybeLiveRetUses[0]);
- if (RetValLiveness[0] != Live)
- // If the entire retval (0) is Live, MarkValue will have marked all other retvals live
- // as well, so we can skip this.
- for (unsigned i = 0; i != PartialRetVals; ++i)
- // + 1 to skip the "entire retval" index (0)
- MarkValue(CreateRet(&F, i), RetValLiveness[i + 1], MaybeLiveRetUses[i + 1]);
+ for (unsigned i = 0; i != RetCount; ++i)
+ MarkValue(CreateRet(&F, i), RetValLiveness[i], MaybeLiveRetUses[i]);
- DOUT << "DAE - Inspecting args for fn: " << F.getName() << "\n";
+ DEBUG(dbgs() << "DAE - Inspecting args for fn: " << F.getName() << "\n");
// Now, check all of our arguments.
unsigned i = 0;
UseVector MaybeLiveArgUses;
- for (Function::arg_iterator AI = F.arg_begin(),
+ for (Function::const_arg_iterator AI = F.arg_begin(),
E = F.arg_end(); AI != E; ++AI, ++i) {
// See what the effect of this use is (recording any uses that cause
// MaybeLive in MaybeLiveArgUses).
/// mark any values that are used as this function's parameters or by its return
/// values (according to Uses) live as well.
void DAE::MarkLive(const Function &F) {
- DOUT << "DAE - Intrinsically live fn: " << F.getName() << "\n";
- // Mark the function as live.
- LiveFunctions.insert(&F);
- // Mark all arguments as live.
- for (unsigned i = 0, e = F.arg_size(); i != e; ++i)
- PropagateLiveness(CreateArg(&F, i));
- // Mark all return values as live.
- const Type *RTy = F.getFunctionType()->getReturnType();
- if (const StructType *STy = dyn_cast<StructType>(RTy))
- for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
- PropagateLiveness(CreateRet(&F, i));
- PropagateLiveness(CreateRet(&F, -1));
+ DEBUG(dbgs() << "DAE - Intrinsically live fn: " << F.getName() << "\n");
+ // Mark the function as live.
+ LiveFunctions.insert(&F);
+ // Mark all arguments as live.
+ for (unsigned i = 0, e = F.arg_size(); i != e; ++i)
+ PropagateLiveness(CreateArg(&F, i));
+ // Mark all return values as live.
+ for (unsigned i = 0, e = NumRetVals(&F); i != e; ++i)
+ PropagateLiveness(CreateRet(&F, i));
}
/// MarkLive - Mark the given return value or argument as live. Additionally,
if (!LiveValues.insert(RA).second)
return; // We were already marked Live.
- DOUT << "DAE - Marking " << RA.getDescription() << " live\n";
+ DEBUG(dbgs() << "DAE - Marking " << RA.getDescription() << " live\n");
PropagateLiveness(RA);
-
- if (!RA.IsArg && RA.Idx == -1) {
- // Entire return value live?
- const Type *RTy = RA.F->getFunctionType()->getReturnType();
- if (const StructType *STy = dyn_cast<StructType>(RTy))
- // And the function returns a struct?
- for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
- // Mark all partial return values live as well then
- MarkLive(CreateRet(RA.F, i));
- }
}
/// PropagateLiveness - Given that RA is a live value, propagate it's liveness
std::vector<const Type*> Params;
// Set up to build a new list of parameter attributes.
- SmallVector<ParamAttrsWithIndex, 8> ParamAttrsVec;
- const PAListPtr &PAL = F->getParamAttrs();
+ SmallVector<AttributeWithIndex, 8> AttributesVec;
+ const AttrListPtr &PAL = F->getAttributes();
// The existing function return attributes.
- ParameterAttributes RAttrs = PAL.getParamAttrs(0);
-
+ Attributes RAttrs = PAL.getRetAttributes();
+ Attributes FnAttrs = PAL.getFnAttributes();
// Find out the new return value.
const Type *RetTy = FTy->getReturnType();
- const StructType *STy = dyn_cast<StructType>(RetTy);
- const unsigned PartialRetVals = (STy ? STy->getNumElements() : 0);
const Type *NRetTy = NULL;
- // -1 means unused, other numbers are the new index. Initialized to -1 for
- // every partial return value we have.
- SmallVector<int, 5> NewRetIdxs(PartialRetVals, -1);
+ unsigned RetCount = NumRetVals(F);
+
+ // -1 means unused, other numbers are the new index
+ SmallVector<int, 5> NewRetIdxs(RetCount, -1);
std::vector<const Type*> RetTypes;
- if (LiveValues.count(CreateRet(F, -1))) {
- // If the entire return value is live, leave it unchanged.
+ if (RetTy->isVoidTy()) {
NRetTy = RetTy;
} else {
- if (STy) {
- // Look at each of the partial return values individually.
- for (unsigned i = 0; i != PartialRetVals; ++i) {
+ const StructType *STy = dyn_cast<StructType>(RetTy);
+ if (STy)
+ // Look at each of the original return values individually.
+ for (unsigned i = 0; i != RetCount; ++i) {
RetOrArg Ret = CreateRet(F, i);
if (LiveValues.erase(Ret)) {
RetTypes.push_back(STy->getElementType(i));
NewRetIdxs[i] = RetTypes.size() - 1;
} else {
++NumRetValsEliminated;
- DOUT << "DAE - Removing return value " << i << " from "
- << F->getNameStart() << "\n";
- // We remove the value by not adding anything to RetTypes.
+ DEBUG(dbgs() << "DAE - Removing return value " << i << " from "
+ << F->getName() << "\n");
}
}
- } else if (RetTy != Type::VoidTy) {
- // We used to return a single value, which is now dead (already checked in
- // the if above)
- DOUT << "DAE - Removing return value from " << F->getNameStart()
- << "\n";
- ++NumRetValsEliminated;
- // We remove the value by not adding anything to RetTypes.
- }
-
+ else
+ // We used to return a single value.
+ if (LiveValues.erase(CreateRet(F, 0))) {
+ RetTypes.push_back(RetTy);
+ NewRetIdxs[0] = 0;
+ } else {
+ DEBUG(dbgs() << "DAE - Removing return value from " << F->getName()
+ << "\n");
+ ++NumRetValsEliminated;
+ }
if (RetTypes.size() > 1)
- // More than one return type? Return a struct with them.
+ // More than one return type? Return a struct with them. Also, if we used
+ // to return a struct and didn't change the number of return values,
+ // return a struct again. This prevents changing {something} into
+ // something and {} into void.
// Make the new struct packed if we used to return a packed struct
// already.
- NRetTy = StructType::get(RetTypes, STy->isPacked());
+ NRetTy = StructType::get(STy->getContext(), RetTypes, STy->isPacked());
else if (RetTypes.size() == 1)
// One return type? Just a simple value then, but only if we didn't use to
// return a struct with that simple value before.
NRetTy = RetTypes.front();
else if (RetTypes.size() == 0)
- // No return types? Make it void.
- NRetTy = Type::VoidTy;
+ // No return types? Make it void, but only if we didn't use to return {}.
+ NRetTy = Type::getVoidTy(F->getContext());
}
assert(NRetTy && "No new return type found?");
// values. Otherwise, ensure that we don't have any conflicting attributes
// here. Currently, this should not be possible, but special handling might be
// required when new return value attributes are added.
- if (NRetTy == Type::VoidTy)
- RAttrs &= ~ParamAttr::typeIncompatible(NRetTy);
+ if (NRetTy->isVoidTy())
+ RAttrs &= ~Attribute::typeIncompatible(NRetTy);
else
- assert((RAttrs & ParamAttr::typeIncompatible(NRetTy)) == 0
+ assert((RAttrs & Attribute::typeIncompatible(NRetTy)) == 0
&& "Return attributes no longer compatible?");
if (RAttrs)
- ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, RAttrs));
+ AttributesVec.push_back(AttributeWithIndex::get(0, RAttrs));
// Remember which arguments are still alive.
SmallVector<bool, 10> ArgAlive(FTy->getNumParams(), false);
// Get the original parameter attributes (skipping the first one, that is
// for the return value.
- if (ParameterAttributes Attrs = PAL.getParamAttrs(i + 1))
- ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Params.size(), Attrs));
+ if (Attributes Attrs = PAL.getParamAttributes(i + 1))
+ AttributesVec.push_back(AttributeWithIndex::get(Params.size(), Attrs));
} else {
++NumArgumentsEliminated;
- DOUT << "DAE - Removing argument " << i << " (" << I->getNameStart()
- << ") from " << F->getNameStart() << "\n";
+ DEBUG(dbgs() << "DAE - Removing argument " << i << " (" << I->getName()
+ << ") from " << F->getName() << "\n");
}
}
- // Reconstruct the ParamAttrsList based on the vector we constructed.
- PAListPtr NewPAL = PAListPtr::get(ParamAttrsVec.begin(), ParamAttrsVec.end());
+ if (FnAttrs != Attribute::None)
+ AttributesVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
- // Work around LLVM bug PR56: the CWriter cannot emit varargs functions which
- // have zero fixed arguments.
- //
- // Note that we apply this hack for a vararg fuction that does not have any
- // arguments anymore, but did have them before (so don't bother fixing
- // functions that were already broken wrt CWriter).
- bool ExtraArgHack = false;
- if (Params.empty() && FTy->isVarArg() && FTy->getNumParams() != 0) {
- ExtraArgHack = true;
- Params.push_back(Type::Int32Ty);
- }
+ // Reconstruct the AttributesList based on the vector we constructed.
+ AttrListPtr NewPAL = AttrListPtr::get(AttributesVec.begin(),
+ AttributesVec.end());
// Create the new function type based on the recomputed parameters.
FunctionType *NFTy = FunctionType::get(NRetTy, Params, FTy->isVarArg());
// Create the new function body and insert it into the module...
Function *NF = Function::Create(NFTy, F->getLinkage());
NF->copyAttributesFrom(F);
- NF->setParamAttrs(NewPAL);
+ NF->setAttributes(NewPAL);
// Insert the new function before the old function, so we won't be processing
// it again.
F->getParent()->getFunctionList().insert(F, NF);
CallSite CS = CallSite::get(F->use_back());
Instruction *Call = CS.getInstruction();
- ParamAttrsVec.clear();
- const PAListPtr &CallPAL = CS.getParamAttrs();
+ AttributesVec.clear();
+ const AttrListPtr &CallPAL = CS.getAttributes();
// The call return attributes.
- ParameterAttributes RAttrs = CallPAL.getParamAttrs(0);
+ Attributes RAttrs = CallPAL.getRetAttributes();
+ Attributes FnAttrs = CallPAL.getFnAttributes();
// Adjust in case the function was changed to return void.
- RAttrs &= ~ParamAttr::typeIncompatible(NF->getReturnType());
+ RAttrs &= ~Attribute::typeIncompatible(NF->getReturnType());
if (RAttrs)
- ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, RAttrs));
+ AttributesVec.push_back(AttributeWithIndex::get(0, RAttrs));
// Declare these outside of the loops, so we can reuse them for the second
// loop, which loops the varargs.
if (ArgAlive[i]) {
Args.push_back(*I);
// Get original parameter attributes, but skip return attributes.
- if (ParameterAttributes Attrs = CallPAL.getParamAttrs(i + 1))
- ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Args.size(), Attrs));
+ if (Attributes Attrs = CallPAL.getParamAttributes(i + 1))
+ AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs));
}
- if (ExtraArgHack)
- Args.push_back(UndefValue::get(Type::Int32Ty));
-
// Push any varargs arguments on the list. Don't forget their attributes.
for (CallSite::arg_iterator E = CS.arg_end(); I != E; ++I, ++i) {
Args.push_back(*I);
- if (ParameterAttributes Attrs = CallPAL.getParamAttrs(i + 1))
- ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Args.size(), Attrs));
+ if (Attributes Attrs = CallPAL.getParamAttributes(i + 1))
+ AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs));
}
- // Reconstruct the ParamAttrsList based on the vector we constructed.
- PAListPtr NewCallPAL = PAListPtr::get(ParamAttrsVec.begin(),
- ParamAttrsVec.end());
+ if (FnAttrs != Attribute::None)
+ AttributesVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
+
+ // Reconstruct the AttributesList based on the vector we constructed.
+ AttrListPtr NewCallPAL = AttrListPtr::get(AttributesVec.begin(),
+ AttributesVec.end());
Instruction *New;
if (InvokeInst *II = dyn_cast<InvokeInst>(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);
+ cast<InvokeInst>(New)->setAttributes(NewCallPAL);
} else {
New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call);
cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
- cast<CallInst>(New)->setParamAttrs(NewCallPAL);
+ cast<CallInst>(New)->setAttributes(NewCallPAL);
if (cast<CallInst>(Call)->isTailCall())
cast<CallInst>(New)->setTailCall();
}
+ New->setDebugLoc(Call->getDebugLoc());
+
Args.clear();
if (!Call->use_empty()) {
// Return type not changed? Just replace users then.
Call->replaceAllUsesWith(New);
New->takeName(Call);
- } else if (New->getType() == Type::VoidTy) {
+ } else if (New->getType()->isVoidTy()) {
// Our return value has uses, but they will get removed later on.
// Replace by null for now.
Call->replaceAllUsesWith(Constant::getNullValue(Call->getType()));
} else {
- assert(isa<StructType>(RetTy) && "Return type changed, but not into a"
- "void. The old return type must have"
- "been a struct!");
- // The original return value was a struct, update all uses (which are
- // all extractvalue instructions, or uses that are unused themselves).
- for (Value::use_iterator I = Call->use_begin(), E = Call->use_end();
- I != E;) {
- if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(*I)) {
- // Increment now, since we're about to throw away this use.
- ++I;
- assert(EV->hasIndices() && "Return value used by extractvalue without"
- "indices?");
- unsigned Idx = *EV->idx_begin();
- if (NewRetIdxs[Idx] != -1) {
- if (RetTypes.size() > 1) {
- // We're still returning a struct, create a new extractvalue
- // instruction with the first index updated
- std::vector<unsigned> NewIdxs(EV->idx_begin(), EV->idx_end());
- NewIdxs[0] = NewRetIdxs[Idx];
- Value *NEV = ExtractValueInst::Create(New, NewIdxs.begin(),
- NewIdxs.end(), "retval",
- EV);
- EV->replaceAllUsesWith(NEV);
- EV->eraseFromParent();
- } else {
- // We are now only returning a simple value, remove the
- // extractvalue.
- EV->replaceAllUsesWith(New);
- EV->eraseFromParent();
- }
- } else {
- // Value unused, replace uses by null for now, they will get removed
- // later on.
- EV->replaceAllUsesWith(Constant::getNullValue(EV->getType()));
- EV->eraseFromParent();
- }
- } else {
- // Not an extractvalue, so this use will become dead soon. Just
- // replace it with null.
- I.getUse().set(Constant::getNullValue(I.getUse().get()->getType()));
- }
+ assert(RetTy->isStructTy() &&
+ "Return type changed, but not into a void. The old return type"
+ " must have been a struct!");
+ Instruction *InsertPt = Call;
+ if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
+ BasicBlock::iterator IP = II->getNormalDest()->begin();
+ while (isa<PHINode>(IP)) ++IP;
+ InsertPt = IP;
}
+
+ // We used to return a struct. Instead of doing smart stuff with all the
+ // uses of this struct, we will just rebuild it using
+ // extract/insertvalue chaining and let instcombine clean that up.
+ //
+ // Start out building up our return value from undef
+ Value *RetVal = UndefValue::get(RetTy);
+ for (unsigned i = 0; i != RetCount; ++i)
+ if (NewRetIdxs[i] != -1) {
+ Value *V;
+ if (RetTypes.size() > 1)
+ // We are still returning a struct, so extract the value from our
+ // return value
+ V = ExtractValueInst::Create(New, NewRetIdxs[i], "newret",
+ InsertPt);
+ else
+ // We are now returning a single element, so just insert that
+ V = New;
+ // Insert the value at the old position
+ RetVal = InsertValueInst::Create(RetVal, V, i, "oldret", InsertPt);
+ }
+ // Now, replace all uses of the old call instruction with the return
+ // struct we built
+ Call->replaceAllUsesWith(RetVal);
New->takeName(Call);
}
}
if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
Value *RetVal;
- if (NFTy->getReturnType() == Type::VoidTy) {
+ if (NFTy->getReturnType()->isVoidTy()) {
RetVal = 0;
} else {
- assert (isa<StructType>(RetTy));
+ assert (RetTy->isStructTy());
// The original return value was a struct, insert
// extractvalue/insertvalue chains to extract only the values we need
// to return and insert them into our new result.
// clean that up.
Value *OldRet = RI->getOperand(0);
// Start out building up our return value from undef
- RetVal = llvm::UndefValue::get(NRetTy);
- for (unsigned i = 0; i != PartialRetVals; ++i)
+ RetVal = UndefValue::get(NRetTy);
+ for (unsigned i = 0; i != RetCount; ++i)
if (NewRetIdxs[i] != -1) {
ExtractValueInst *EV = ExtractValueInst::Create(OldRet, i,
"oldret", RI);
}
// Replace the return instruction with one returning the new return
// value (possibly 0 if we became void).
- ReturnInst::Create(RetVal, RI);
+ ReturnInst::Create(F->getContext(), RetVal, RI);
BB->getInstList().erase(RI);
}
// 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";
+ DEBUG(dbgs() << "DAE - Deleting dead varargs\n");
for (Module::iterator I = M.begin(), E = M.end(); I != E; ) {
Function &F = *I++;
if (F.getFunctionType()->isVarArg())
// 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";
+ DEBUG(dbgs() << "DAE - Determining liveness\n");
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
SurveyFunction(*I);
-
+
// Now, remove all dead arguments and return values from each function in
- // turn
+ // turn.
for (Module::iterator I = M.begin(), E = M.end(); I != E; ) {
- // Increment now, because the function will probably get removed (ie
+ // Increment now, because the function will probably get removed (ie.
// replaced by a new one).
Function *F = I++;
Changed |= RemoveDeadStuffFromFunction(F);
projects / oota-llvm.git / blobdiff