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Cloning: Clean up the interface to the CloneFunction function. 

Remove the ModuleLevelChanges argument, and the ability to create new
subprograms for cloned functions. The latter was added without review in
r203662, but it has no in-tree clients (all non-test callers pass false
for ModuleLevelChanges [1], so it isn't reachable outside of tests). It
also isn't clear that adding a duplicate subprogram to the compile unit is
always the right thing to do when cloning a function within a module. If
this functionality comes back it should be accompanied with a more concrete
use case.

Furthermore, all in-tree clients add the returned function to the module.
Since that's pretty much the only sensible thing you can do with the function,
just do that in CloneFunction.

[1] http://llvm-cs.pcc.me.uk/lib/Transforms/Utils/CloneFunction.cpp/rCloneFunction

Differential Revision: http://reviews.llvm.org/D18628

llvm-svn: 269110
This commit is contained in:
Peter Collingbourne 2016-05-10 20:23:24 +00:00
parent 4e6cda2db5
commit dba995601b
5 changed files with 30 additions and 54 deletions
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23
llvm/include/llvm/Transforms/Utils/Cloning.h
View File

@ -114,20 +114,19 @@ BasicBlock *CloneBasicBlock(const BasicBlock *BB, ValueToValueMapTy &VMap,
const Twine &NameSuffix = "", Function *F = nullptr,
ClonedCodeInfo *CodeInfo = nullptr);
/// CloneFunction - Return a copy of the specified function, but without
/// embedding the function into another module. Also, any references specified
/// in the VMap are changed to refer to their mapped value instead of the
/// original one. If any of the arguments to the function are in the VMap,
/// the arguments are deleted from the resultant function. The VMap is
/// updated to include mappings from all of the instructions and basicblocks in
/// the function from their old to new values. The final argument captures
/// information about the cloned code if non-null.
/// CloneFunction - Return a copy of the specified function and add it to that
/// function's module. Also, any references specified in the VMap are changed
/// to refer to their mapped value instead of the original one. If any of the
/// arguments to the function are in the VMap, the arguments are deleted from
/// the resultant function. The VMap is updated to include mappings from all of
/// the instructions and basicblocks in the function from their old to new
/// values. The final argument captures information about the cloned code if
/// non-null.
///
/// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
/// mappings, and debug info metadata will not be cloned.
/// VMap contains no non-identity GlobalValue mappings and debug info metadata
/// will not be cloned.
///
Function *CloneFunction(const Function *F, ValueToValueMapTy &VMap,
bool ModuleLevelChanges,
Function *CloneFunction(Function *F, ValueToValueMapTy &VMap,
ClonedCodeInfo *CodeInfo = nullptr);
/// Clone OldFunc into NewFunc, transforming the old arguments into references

3
llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp
View File

@ -45,9 +45,8 @@ bool AMDGPUAlwaysInline::runOnModule(Module &M) {
for (Function *F : FuncsToClone) {
ValueToValueMapTy VMap;
Function *NewFunc = CloneFunction(F, VMap, false);
Function *NewFunc = CloneFunction(F, VMap);
NewFunc->setLinkage(GlobalValue::InternalLinkage);
M.getFunctionList().push_back(NewFunc);
F->replaceAllUsesWith(NewFunc);
}

4
llvm/lib/Transforms/IPO/PartialInlining.cpp
View File

@ -71,10 +71,8 @@ Function* PartialInliner::unswitchFunction(Function* F) {
// Clone the function, so that we can hack away on it.
ValueToValueMapTy VMap;
Function* duplicateFunction = CloneFunction(F, VMap,
/*ModuleLevelChanges=*/false);
Function* duplicateFunction = CloneFunction(F, VMap);
duplicateFunction->setLinkage(GlobalValue::InternalLinkage);
F->getParent()->getFunctionList().push_back(duplicateFunction);
BasicBlock* newEntryBlock = cast<BasicBlock>(VMap[entryBlock]);
BasicBlock* newReturnBlock = cast<BasicBlock>(VMap[returnBlock]);
BasicBlock* newNonReturnBlock = cast<BasicBlock>(VMap[nonReturnBlock]);

40
llvm/lib/Transforms/Utils/CloneFunction.cpp
View File

@ -172,30 +172,14 @@ void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
TypeMapper, Materializer);
}
// Clone the module-level debug info associated with OldFunc. The cloned data
// will point to NewFunc instead.
static void CloneDebugInfoMetadata(Function *NewFunc, const Function *OldFunc,
ValueToValueMapTy &VMap) {
if (const DISubprogram *OldSP = OldFunc->getSubprogram()) {
auto *NewSP = cast<DISubprogram>(MapMetadata(OldSP, VMap));
// FIXME: There ought to be a better way to do this: ValueMapper
// will clone the distinct DICompileUnit. Use the original one
// instead.
NewSP->replaceUnit(OldSP->getUnit());
NewFunc->setSubprogram(NewSP);
}
}
/// Return a copy of the specified function, but without
/// embedding the function into another module. Also, any references specified
/// in the VMap are changed to refer to their mapped value instead of the
/// original one. If any of the arguments to the function are in the VMap,
/// the arguments are deleted from the resultant function. The VMap is
/// updated to include mappings from all of the instructions and basicblocks in
/// the function from their old to new values.
/// Return a copy of the specified function and add it to that function's
/// module. Also, any references specified in the VMap are changed to refer to
/// their mapped value instead of the original one. If any of the arguments to
/// the function are in the VMap, the arguments are deleted from the resultant
/// function. The VMap is updated to include mappings from all of the
/// instructions and basicblocks in the function from their old to new values.
///
Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap,
bool ModuleLevelChanges,
Function *llvm::CloneFunction(Function *F, ValueToValueMapTy &VMap,
ClonedCodeInfo *CodeInfo) {
std::vector<Type*> ArgTypes;
@ -211,7 +195,8 @@ Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap,
ArgTypes, F->getFunctionType()->isVarArg());
// Create the new function...
Function *NewF = Function::Create(FTy, F->getLinkage(), F->getName());
Function *NewF =
Function::Create(FTy, F->getLinkage(), F->getName(), F->getParent());
// Loop over the arguments, copying the names of the mapped arguments over...
Function::arg_iterator DestI = NewF->arg_begin();
@ -221,11 +206,10 @@ Function *llvm::CloneFunction(const Function *F, ValueToValueMapTy &VMap,
VMap[&I] = &*DestI++; // Add mapping to VMap
}
if (ModuleLevelChanges)
CloneDebugInfoMetadata(NewF, F, VMap);
SmallVector<ReturnInst*, 8> Returns; // Ignore returns cloned.
CloneFunctionInto(NewF, F, VMap, ModuleLevelChanges, Returns, "", CodeInfo);
CloneFunctionInto(NewF, F, VMap, /*ModuleLevelChanges=*/false, Returns, "",
CodeInfo);
return NewF;
}

14
llvm/unittests/Transforms/Utils/Cloning.cpp
View File

@ -274,8 +274,7 @@ protected:
void CreateNewFunc() {
ValueToValueMapTy VMap;
NewFunc = CloneFunction(OldFunc, VMap, true, nullptr);
M->getFunctionList().push_back(NewFunc);
NewFunc = CloneFunction(OldFunc, VMap, nullptr);
}
void SetupFinder() {
@ -301,16 +300,13 @@ TEST_F(CloneFunc, Subprogram) {
EXPECT_FALSE(verifyModule(*M));
unsigned SubprogramCount = Finder->subprogram_count();
EXPECT_EQ(2U, SubprogramCount);
EXPECT_EQ(1U, SubprogramCount);
auto Iter = Finder->subprograms().begin();
auto *Sub1 = cast<DISubprogram>(*Iter);
Iter++;
auto *Sub2 = cast<DISubprogram>(*Iter);
auto *Sub = cast<DISubprogram>(*Iter);
EXPECT_TRUE(
(Sub1 == OldFunc->getSubprogram() && Sub2 == NewFunc->getSubprogram()) ||
(Sub1 == NewFunc->getSubprogram() && Sub2 == OldFunc->getSubprogram()));
EXPECT_TRUE(Sub == OldFunc->getSubprogram());
EXPECT_TRUE(Sub == NewFunc->getSubprogram());
}
// Test that instructions in the old function still belong to it in the