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authorJames Molloy <james.molloy@arm.com>2013-05-28 15:17:05 +0000
committerJames Molloy <james.molloy@arm.com>2013-05-28 15:17:05 +0000
commita84a83bbcdfaecadfc6574094272fd3edc429a23 (patch)
treeca87000d15263653ac635164ab194745b87f46e6 /lib/Linker
parent9903f75bf6ec4136bd752595c689db845eedad3d (diff)
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Extend RemapInstruction and friends to take an optional new parameter, a ValueMaterializer.
Extend LinkModules to pass a ValueMaterializer to RemapInstruction and friends to lazily create Functions for lazily linked globals. This is a big win when linking small modules with large (mostly unused) library modules. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182776 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Linker')
-rw-r--r--lib/Linker/LinkModules.cpp127
1 files changed, 77 insertions, 50 deletions
diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index d2e13c9..f322112 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -353,12 +353,32 @@ Type *TypeMapTy::getImpl(Type *Ty) {
//===----------------------------------------------------------------------===//
namespace {
+ class ModuleLinker;
+
+ /// ValueMaterializerTy - Creates prototypes for functions that are lazily
+ /// linked on the fly. This speeds up linking for modules with many
+ /// lazily linked functions of which few get used.
+ class ValueMaterializerTy : public ValueMaterializer {
+ TypeMapTy &TypeMap;
+ Module *DstM;
+ std::vector<Function*> &LazilyLinkFunctions;
+ public:
+ ValueMaterializerTy(TypeMapTy &TypeMap, Module *DstM,
+ std::vector<Function*> &LazilyLinkFunctions) :
+ ValueMaterializer(), TypeMap(TypeMap), DstM(DstM),
+ LazilyLinkFunctions(LazilyLinkFunctions) {
+ }
+
+ virtual Value *materializeValueFor(Value *V);
+ };
+
/// ModuleLinker - This is an implementation class for the LinkModules
/// function, which is the entrypoint for this file.
class ModuleLinker {
Module *DstM, *SrcM;
TypeMapTy TypeMap;
+ ValueMaterializerTy ValMaterializer;
/// ValueMap - Mapping of values from what they used to be in Src, to what
/// they are now in DstM. ValueToValueMapTy is a ValueMap, which involves
@@ -386,7 +406,9 @@ namespace {
std::string ErrorMsg;
ModuleLinker(Module *dstM, TypeSet &Set, Module *srcM, unsigned mode)
- : DstM(dstM), SrcM(srcM), TypeMap(Set), Mode(mode) { }
+ : DstM(dstM), SrcM(srcM), TypeMap(Set),
+ ValMaterializer(TypeMap, DstM, LazilyLinkFunctions),
+ Mode(mode) { }
bool run();
@@ -487,6 +509,20 @@ static bool isLessConstraining(GlobalValue::VisibilityTypes a,
return false;
}
+Value *ValueMaterializerTy::materializeValueFor(Value *V) {
+ Function *SF = dyn_cast<Function>(V);
+ if (!SF)
+ return NULL;
+
+ Function *DF = Function::Create(TypeMap.get(SF->getFunctionType()),
+ SF->getLinkage(), SF->getName(), DstM);
+ copyGVAttributes(DF, SF);
+
+ LazilyLinkFunctions.push_back(SF);
+ return DF;
+}
+
+
/// getLinkageResult - This analyzes the two global values and determines what
/// the result will look like in the destination module. In particular, it
/// computes the resultant linkage type and visibility, computes whether the
@@ -802,6 +838,14 @@ bool ModuleLinker::linkFunctionProto(Function *SF) {
}
}
+ // If the function is to be lazily linked, don't create it just yet.
+ // The ValueMaterializerTy will deal with creating it if it's used.
+ if (!DGV && (SF->hasLocalLinkage() || SF->hasLinkOnceLinkage() ||
+ SF->hasAvailableExternallyLinkage())) {
+ DoNotLinkFromSource.insert(SF);
+ return false;
+ }
+
// If there is no linkage to be performed or we are linking from the source,
// bring SF over.
Function *NewDF = Function::Create(TypeMap.get(SF->getFunctionType()),
@@ -814,13 +858,6 @@ bool ModuleLinker::linkFunctionProto(Function *SF) {
// Any uses of DF need to change to NewDF, with cast.
DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDF, DGV->getType()));
DGV->eraseFromParent();
- } else {
- // Internal, LO_ODR, or LO linkage - stick in set to ignore and lazily link.
- if (SF->hasLocalLinkage() || SF->hasLinkOnceLinkage() ||
- SF->hasAvailableExternallyLinkage()) {
- DoNotLinkFromSource.insert(SF);
- LazilyLinkFunctions.push_back(SF);
- }
}
ValueMap[SF] = NewDF;
@@ -887,7 +924,7 @@ void ModuleLinker::linkAppendingVarInit(const AppendingVarInfo &AVI) {
SmallVector<Constant*, 16> Elements;
getArrayElements(AVI.DstInit, Elements);
- Constant *SrcInit = MapValue(AVI.SrcInit, ValueMap, RF_None, &TypeMap);
+ Constant *SrcInit = MapValue(AVI.SrcInit, ValueMap, RF_None, &TypeMap, &ValMaterializer);
getArrayElements(SrcInit, Elements);
ArrayType *NewType = cast<ArrayType>(AVI.NewGV->getType()->getElementType());
@@ -908,7 +945,7 @@ void ModuleLinker::linkGlobalInits() {
GlobalVariable *DGV = cast<GlobalVariable>(ValueMap[I]);
// Figure out what the initializer looks like in the dest module.
DGV->setInitializer(MapValue(I->getInitializer(), ValueMap,
- RF_None, &TypeMap));
+ RF_None, &TypeMap, &ValMaterializer));
}
}
@@ -938,12 +975,14 @@ void ModuleLinker::linkFunctionBody(Function *Dst, Function *Src) {
// functions and patch them up to point to the local versions.
for (Function::iterator BB = Dst->begin(), BE = Dst->end(); BB != BE; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- RemapInstruction(I, ValueMap, RF_IgnoreMissingEntries, &TypeMap);
+ RemapInstruction(I, ValueMap, RF_IgnoreMissingEntries,
+ &TypeMap, &ValMaterializer);
} else {
// Clone the body of the function into the dest function.
SmallVector<ReturnInst*, 8> Returns; // Ignore returns.
- CloneFunctionInto(Dst, Src, ValueMap, false, Returns, "", NULL, &TypeMap);
+ CloneFunctionInto(Dst, Src, ValueMap, false, Returns, "", NULL,
+ &TypeMap, &ValMaterializer);
}
// There is no need to map the arguments anymore.
@@ -961,7 +1000,8 @@ void ModuleLinker::linkAliasBodies() {
continue;
if (Constant *Aliasee = I->getAliasee()) {
GlobalAlias *DA = cast<GlobalAlias>(ValueMap[I]);
- DA->setAliasee(MapValue(Aliasee, ValueMap, RF_None, &TypeMap));
+ DA->setAliasee(MapValue(Aliasee, ValueMap, RF_None,
+ &TypeMap, &ValMaterializer));
}
}
}
@@ -978,7 +1018,7 @@ void ModuleLinker::linkNamedMDNodes() {
// Add Src elements into Dest node.
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
DestNMD->addOperand(MapValue(I->getOperand(i), ValueMap,
- RF_None, &TypeMap));
+ RF_None, &TypeMap, &ValMaterializer));
}
}
@@ -1238,49 +1278,36 @@ bool ModuleLinker::run() {
LinkedInAnyFunctions = false;
for(std::vector<Function*>::iterator I = LazilyLinkFunctions.begin(),
- E = LazilyLinkFunctions.end(); I != E; ++I) {
- if (!*I)
- continue;
-
+ E = LazilyLinkFunctions.end(); I != E; ++I) {
Function *SF = *I;
+ if (!SF)
+ continue;
+
Function *DF = cast<Function>(ValueMap[SF]);
-
- if (!DF->use_empty()) {
-
- // Materialize if necessary.
- if (SF->isDeclaration()) {
- if (!SF->isMaterializable())
- continue;
- if (SF->Materialize(&ErrorMsg))
- return true;
- }
-
- // Link in function body.
- linkFunctionBody(DF, SF);
- SF->Dematerialize();
- // "Remove" from vector by setting the element to 0.
- *I = 0;
-
- // Set flag to indicate we may have more functions to lazily link in
- // since we linked in a function.
- LinkedInAnyFunctions = true;
+ // Materialize if necessary.
+ if (SF->isDeclaration()) {
+ if (!SF->isMaterializable())
+ continue;
+ if (SF->Materialize(&ErrorMsg))
+ return true;
}
+
+ // Erase from vector *before* the function body is linked - linkFunctionBody could
+ // invalidate I.
+ LazilyLinkFunctions.erase(I);
+
+ // Link in function body.
+ linkFunctionBody(DF, SF);
+ SF->Dematerialize();
+
+ // Set flag to indicate we may have more functions to lazily link in
+ // since we linked in a function.
+ LinkedInAnyFunctions = true;
+ break;
}
} while (LinkedInAnyFunctions);
- // Remove any prototypes of functions that were not actually linked in.
- for(std::vector<Function*>::iterator I = LazilyLinkFunctions.begin(),
- E = LazilyLinkFunctions.end(); I != E; ++I) {
- if (!*I)
- continue;
-
- Function *SF = *I;
- Function *DF = cast<Function>(ValueMap[SF]);
- if (DF->use_empty())
- DF->eraseFromParent();
- }
-
// Now that all of the types from the source are used, resolve any structs
// copied over to the dest that didn't exist there.
TypeMap.linkDefinedTypeBodies();