/* Change linkages of global values, in order to
* improve alias analysis.
*/
bool DeadStoreEliminationPass::changeLinkageTypes(Module &M) {
DEBUG(errs() << "Changing linkages to private...\n");
for (Module::global_iterator git = M.global_begin(), gitE = M.global_end();
git != gitE; ++git) {
DEBUG(errs() << " " << *git << "\n");
if (!git->hasExternalLinkage() && !git->hasAppendingLinkage()) git->setLinkage(GlobalValue::PrivateLinkage);
}
for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
if (!F->isDeclaration()) {
if (!F->hasExternalLinkage() && !F->hasAppendingLinkage()) F->setLinkage(GlobalValue::PrivateLinkage);
DEBUG(errs() << " " << F->getName() << "\n");
}
}
DEBUG(errs() << "\n");
return true;
}
/// doInitialization - Perform Module level initializations here.
/// One task that we do here is to sectionize all global variables.
/// The MemSelOptimizer pass depends on the sectionizing.
///
bool PIC16AsmPrinter::doInitialization(Module &M) {
bool Result = AsmPrinter::doInitialization(M);
// Every asmbly contains these std headers.
O << "\n#include p16f1xxx.inc";
O << "\n#include stdmacros.inc";
// Set the section names for all globals.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
// Record External Var Decls.
if (I->isDeclaration()) {
ExternalVarDecls.push_back(I);
continue;
}
// Record Exteranl Var Defs.
if (I->hasExternalLinkage() || I->hasCommonLinkage()) {
ExternalVarDefs.push_back(I);
}
// Sectionify actual data.
if (!I->hasAvailableExternallyLinkage()) {
const MCSection *S = getObjFileLowering().SectionForGlobal(I, Mang, TM);
I->setSection(((const PIC16Section *)S)->getName());
}
}
DbgInfo.BeginModule(M);
EmitFunctionDecls(M);
EmitUndefinedVars(M);
EmitDefinedVars(M);
EmitIData(M);
EmitUData(M);
EmitRomData(M);
EmitSharedUdata(M);
EmitUserSections(M);
return Result;
}
bool GlobalMerge::doInitialization(Module &M) {
if (!EnableGlobalMerge)
return false;
auto &DL = M.getDataLayout();
DenseMap<unsigned, SmallVector<GlobalVariable*, 16> > Globals, ConstGlobals,
BSSGlobals;
bool Changed = false;
setMustKeepGlobalVariables(M);
// Grab all non-const globals.
for (Module::global_iterator I = M.global_begin(),
E = M.global_end(); I != E; ++I) {
// Merge is safe for "normal" internal or external globals only
if (I->isDeclaration() || I->isThreadLocal() || I->hasSection())
continue;
if (!(EnableGlobalMergeOnExternal && I->hasExternalLinkage()) &&
!I->hasInternalLinkage())
continue;
PointerType *PT = dyn_cast<PointerType>(I->getType());
assert(PT && "Global variable is not a pointer!");
unsigned AddressSpace = PT->getAddressSpace();
// Ignore fancy-aligned globals for now.
unsigned Alignment = DL.getPreferredAlignment(I);
Type *Ty = I->getType()->getElementType();
if (Alignment > DL.getABITypeAlignment(Ty))
continue;
// Ignore all 'special' globals.
if (I->getName().startswith("llvm.") ||
I->getName().startswith(".llvm."))
continue;
// Ignore all "required" globals:
if (isMustKeepGlobalVariable(I))
continue;
if (DL.getTypeAllocSize(Ty) < MaxOffset) {
if (TargetLoweringObjectFile::getKindForGlobal(I, *TM).isBSSLocal())
BSSGlobals[AddressSpace].push_back(I);
else if (I->isConstant())
ConstGlobals[AddressSpace].push_back(I);
else
Globals[AddressSpace].push_back(I);
}
}
for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
I = Globals.begin(), E = Globals.end(); I != E; ++I)
if (I->second.size() > 1)
Changed |= doMerge(I->second, M, false, I->first);
for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
I = BSSGlobals.begin(), E = BSSGlobals.end(); I != E; ++I)
if (I->second.size() > 1)
Changed |= doMerge(I->second, M, false, I->first);
if (EnableGlobalMergeOnConst)
for (DenseMap<unsigned, SmallVector<GlobalVariable*, 16> >::iterator
I = ConstGlobals.begin(), E = ConstGlobals.end(); I != E; ++I)
if (I->second.size() > 1)
Changed |= doMerge(I->second, M, true, I->first);
return Changed;
}