bool InlineCostAnalysis::isInlineViable(Function &F) {
bool ReturnsTwice =
F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
Attribute::ReturnsTwice);
for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
// Disallow inlining of functions which contain indirect branches or
// blockaddresses.
if (isa<IndirectBrInst>(BI->getTerminator()) || BI->hasAddressTaken())
return false;
for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
++II) {
CallSite CS(II);
if (!CS)
continue;
// Disallow recursive calls.
if (&F == CS.getCalledFunction())
return false;
// Disallow calls which expose returns-twice to a function not previously
// attributed as such.
if (!ReturnsTwice && CS.isCall() &&
cast<CallInst>(CS.getInstruction())->canReturnTwice())
return false;
}
}
return true;
}
void FunctionLoweringInfo::set(Function &fn, MachineFunction &mf,
bool EnableFastISel) {
Fn = &fn;
MF = &mf;
RegInfo = &MF->getRegInfo();
// Create a vreg for each argument register that is not dead and is used
// outside of the entry block for the function.
for (Function::arg_iterator AI = Fn->arg_begin(), E = Fn->arg_end();
AI != E; ++AI)
if (!isOnlyUsedInEntryBlock(AI, EnableFastISel))
InitializeRegForValue(AI);
// Initialize the mapping of values to registers. This is only set up for
// instruction values that are used outside of the block that defines
// them.
Function::iterator BB = Fn->begin(), EB = Fn->end();
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
if (ConstantInt *CUI = dyn_cast<ConstantInt>(AI->getArraySize())) {
const Type *Ty = AI->getAllocatedType();
uint64_t TySize = TLI.getTargetData()->getTypeAllocSize(Ty);
unsigned Align =
std::max((unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty),
AI->getAlignment());
TySize *= CUI->getZExtValue(); // Get total allocated size.
if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects.
StaticAllocaMap[AI] =
MF->getFrameInfo()->CreateStackObject(TySize, Align, false);
}
for (; BB != EB; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
if (!I->use_empty() && isUsedOutsideOfDefiningBlock(I))
if (!isa<AllocaInst>(I) ||
!StaticAllocaMap.count(cast<AllocaInst>(I)))
InitializeRegForValue(I);
// Create an initial MachineBasicBlock for each LLVM BasicBlock in F. This
// also creates the initial PHI MachineInstrs, though none of the input
// operands are populated.
for (BB = Fn->begin(), EB = Fn->end(); BB != EB; ++BB) {
MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(BB);
MBBMap[BB] = MBB;
MF->push_back(MBB);
// Transfer the address-taken flag. This is necessary because there could
// be multiple MachineBasicBlocks corresponding to one BasicBlock, and only
// the first one should be marked.
if (BB->hasAddressTaken())
MBB->setHasAddressTaken();
// Create Machine PHI nodes for LLVM PHI nodes, lowering them as
// appropriate.
PHINode *PN;
DebugLoc DL;
for (BasicBlock::iterator
I = BB->begin(), E = BB->end(); I != E; ++I) {
PN = dyn_cast<PHINode>(I);
if (!PN || PN->use_empty()) continue;
unsigned PHIReg = ValueMap[PN];
assert(PHIReg && "PHI node does not have an assigned virtual register!");
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, PN->getType(), ValueVTs);
for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
EVT VT = ValueVTs[vti];
unsigned NumRegisters = TLI.getNumRegisters(Fn->getContext(), VT);
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
for (unsigned i = 0; i != NumRegisters; ++i)
BuildMI(MBB, DL, TII->get(TargetOpcode::PHI), PHIReg + i);
PHIReg += NumRegisters;
}
}
}
}
