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[RewriteStatepointsForGC] Hoist some code out of a loop 

llvm-svn: 242808
This commit is contained in:
Philip Reames 2015-07-21 17:18:03 +00:00
parent 3651233004
commit 94babb7030
1 changed files with 13 additions and 12 deletions
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25
llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
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@ -1164,21 +1164,22 @@ static void CreateGCRelocates(ArrayRef<llvm::Value *> LiveVariables,
ArrayRef<llvm::Value *> BasePtrs,
Instruction *StatepointToken,
IRBuilder<> Builder) {
if (LiveVariables.empty())
return;
// All gc_relocate are set to i8 addrspace(1)* type. We originally generated
// unique declarations for each pointer type, but this proved problematic
// because the intrinsic mangling code is incomplete and fragile. Since
// we're moving towards a single unified pointer type anyways, we can just
// cast everything to an i8* of the right address space. A bitcast is added
// later to convert gc_relocate to the actual value's type.
Module *M = StatepointToken->getModule();
auto AS = cast<PointerType>(LiveVariables[0]->getType())->getAddressSpace();
Type *Types[] = {Type::getInt8PtrTy(M->getContext(), AS)};
Value *GCRelocateDecl =
Intrinsic::getDeclaration(M, Intrinsic::experimental_gc_relocate, Types);
for (unsigned i = 0; i < LiveVariables.size(); i++) {
// We generate a (potentially) unique declaration for every pointer type
// combination. This results is some blow up the function declarations in
// the IR, but removes the need for argument bitcasts which shrinks the IR
// greatly and makes it much more readable.
SmallVector<Type *, 1> Types; // one per 'any' type
// All gc_relocate are set to i8 addrspace(1)* type. This could help avoid
// cases where the actual value's type mangling is not supported by llvm. A
// bitcast is added later to convert gc_relocate to the actual value's type.
Types.push_back(Type::getInt8PtrTy(M->getContext(), 1));
Value *GCRelocateDecl = Intrinsic::getDeclaration(
M, Intrinsic::experimental_gc_relocate, Types);
// Generate the gc.relocate call and save the result
Value *BaseIdx =
Builder.getInt32(LiveStart + find_index(LiveVariables, BasePtrs[i]));