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Merge identical block copy/destroy helpers and descriptors #66358

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13 changes: 12 additions & 1 deletion lib/IRGen/GenEnum.h
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Original file line number Diff line number Diff line change
Expand Up @@ -364,7 +364,11 @@ class EnumImplStrategy {
virtual void getSchema(ExplosionSchema &schema) const = 0;
virtual void destroy(IRGenFunction &IGF, Address addr, SILType T,
bool isOutlined) const = 0;

virtual std::string encodeDestroy(IRGenModule &IGM, Alignment alignment,
Size &offset, bool &outIsSupported) const {
outIsSupported = false;
return "";
}
virtual void initializeFromParams(IRGenFunction &IGF, Explosion &params,
Address dest, SILType T,
bool isOutlined) const;
Expand All @@ -375,6 +379,13 @@ class EnumImplStrategy {
SILType T, bool isOutlined) const = 0;
virtual void initializeWithCopy(IRGenFunction &IGF, Address dest, Address src,
SILType T, bool isOutlined) const = 0;
virtual std::string encodeInitializeWithCopy(IRGenModule &IGM,
Alignment alignment,
Size &offset,
bool &outIsSupported) const {
outIsSupported = false;
return "";
}
virtual void initializeWithTake(IRGenFunction &IGF, Address dest, Address src,
SILType T, bool isOutlined) const = 0;

Expand Down
210 changes: 158 additions & 52 deletions lib/IRGen/GenFunc.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,7 @@
#include "swift/AST/Module.h"
#include "swift/AST/Pattern.h"
#include "swift/AST/PrettyStackTrace.h"
#include "swift/AST/ReferenceCounting.h"
#include "swift/AST/SubstitutionMap.h"
#include "swift/AST/Types.h"
#include "swift/IRGen/Linking.h"
Expand All @@ -88,6 +89,8 @@
#include "llvm/IR/Module.h"
#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ScopedPrinter.h"

#include "BitPatternBuilder.h"
#include "Callee.h"
Expand Down Expand Up @@ -307,6 +310,10 @@ namespace {
}
}

bool supportsEncodingInitializeWithCopyAndDestroy() const override {
return true;
}

static Size getFirstElementSize(IRGenModule &IGM) {
return IGM.getPointerSize();
}
Expand Down Expand Up @@ -362,6 +369,15 @@ namespace {
else
IGF.emitNativeStrongAssign(context, dataAddr);
}
std::string encodeRetainSecondElement() const override {
if (isTriviallyDestroyable(ResilienceExpansion::Maximal)) {
return "";
}
return refcountingToString(ReferenceCounting::Native);
}
std::string encodeReleaseSecondElement() const override {
return encodeRetainSecondElement();
}

Address projectFunction(IRGenFunction &IGF, Address address) const {
return projectFirstElement(IGF, address);
Expand Down Expand Up @@ -2257,23 +2273,50 @@ llvm::Optional<StackAddress> irgen::emitFunctionPartialApplication(
return stackAddr;
}

std::string
irgen::getBlockCaptureInitializeKindEncoding(BlockCaptureInitializeKind kind) {
switch (kind) {
case BlockCaptureInitializeKind::Store:
return "S";
}
llvm_unreachable("unhandled BlockCaptureInitializeKind");
}

/// Emit the block copy helper for a block.
static llvm::Function *emitBlockCopyHelper(IRGenModule &IGM,
CanSILBlockStorageType blockTy,
const BlockStorageTypeInfo &blockTL){
// See if we've produced a block copy helper for this type before.
// TODO

auto &captureTL = IGM.getTypeInfoForLowered(blockTy->getCaptureType());
std::string funcName = "block_copy_helper";
bool helperCanBeReused = false;
const auto helperEncoding = captureTL.encodeInitializeWithCopy(
IGM, blockTL.getFixedAlignment(), helperCanBeReused);
if (helperCanBeReused) {
funcName = funcName + "_" +
llvm::to_string(blockTL.getFixedAlignment().getValue()) + "_" +
helperEncoding;
if (auto f = IGM.getModule()->getFunction(funcName))
return f;
}

// Create the helper.
llvm::Type *args[] = {
blockTL.getStorageType()->getPointerTo(),
blockTL.getStorageType()->getPointerTo(),
};
auto copyTy = llvm::FunctionType::get(IGM.VoidTy, args, /*vararg*/ false);
// TODO: Give these predictable mangled names and shared linkage.
auto func = llvm::Function::Create(copyTy, llvm::GlobalValue::InternalLinkage,
"block_copy_helper",
IGM.getModule());
auto func = llvm::Function::Create(copyTy,
helperCanBeReused
? llvm::GlobalValue::LinkOnceODRLinkage
: llvm::GlobalValue::InternalLinkage,
funcName, IGM.getModule());
if (helperCanBeReused) {
if (IGM.Triple.supportsCOMDAT())
func->setComdat(IGM.Module.getOrInsertComdat(funcName));
func->setVisibility(llvm::GlobalValue::HiddenVisibility);
func->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
}
func->setAttributes(IGM.constructInitialAttributes());
IRGenFunction IGF(IGM, func);
if (IGM.DebugInfo)
Expand All @@ -2288,7 +2331,6 @@ static llvm::Function *emitBlockCopyHelper(IRGenModule &IGM,

auto destCapture = blockTL.projectCapture(IGF, dest);
auto srcCapture = blockTL.projectCapture(IGF, src);
auto &captureTL = IGM.getTypeInfoForLowered(blockTy->getCaptureType());
captureTL.initializeWithCopy(IGF, destCapture, srcCapture,
blockTy->getCaptureAddressType(), false);

Expand All @@ -2302,17 +2344,34 @@ static llvm::Function *emitBlockDisposeHelper(IRGenModule &IGM,
CanSILBlockStorageType blockTy,
const BlockStorageTypeInfo &blockTL){
// See if we've produced a block destroy helper for this type before.
// TODO

auto &captureTL = IGM.getTypeInfoForLowered(blockTy->getCaptureType());
std::string funcName = "block_destroy_helper";
bool helperCanBeReused = false;
const auto helperEncoding = captureTL.encodeDestroy(
IGM, blockTL.getFixedAlignment(), helperCanBeReused);
if (helperCanBeReused) {
funcName = funcName + "_" +
llvm::to_string(blockTL.getFixedAlignment().getValue()) + "_" +
helperEncoding;
if (auto f = IGM.getModule()->getFunction(funcName))
return f;
}

// Create the helper.
auto destroyTy = llvm::FunctionType::get(IGM.VoidTy,
blockTL.getStorageType()->getPointerTo(),
/*vararg*/ false);
// TODO: Give these predictable mangled names and shared linkage.
auto destroyTy = llvm::FunctionType::get(
IGM.VoidTy, blockTL.getStorageType()->getPointerTo(),
/*vararg*/ false);
auto func = llvm::Function::Create(destroyTy,
llvm::GlobalValue::InternalLinkage,
"block_destroy_helper",
IGM.getModule());
helperCanBeReused
? llvm::GlobalValue::LinkOnceODRLinkage
: llvm::GlobalValue::InternalLinkage,
funcName, IGM.getModule());
if (helperCanBeReused) {
if (IGM.Triple.supportsCOMDAT())
func->setComdat(IGM.Module.getOrInsertComdat(funcName));
func->setVisibility(llvm::GlobalValue::HiddenVisibility);
func->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
}
func->setAttributes(IGM.constructInitialAttributes());
IRGenFunction IGF(IGM, func);
assert(!func->hasFnAttribute(llvm::Attribute::SanitizeThread));
Expand All @@ -2324,14 +2383,92 @@ static llvm::Function *emitBlockDisposeHelper(IRGenModule &IGM,
auto storage = Address(params.claimNext(), blockTL.getStorageType(),
blockTL.getFixedAlignment());
auto capture = blockTL.projectCapture(IGF, storage);
auto &captureTL = IGM.getTypeInfoForLowered(blockTy->getCaptureType());
captureTL.destroy(IGF, capture, blockTy->getCaptureAddressType(),
false /*block storage code path: never outlined*/);
IGF.Builder.CreateRetVoid();

return func;
}

static llvm::Constant *
buildBlockDescriptor(IRGenFunction &IGF, const BlockStorageTypeInfo &storageTL,
bool isTriviallyDestroyable, CanSILFunctionType invokeTy,
CanSILBlockStorageType blockTy) {
// Lookup identical descriptor created before if capture type allows us to
// reuse.
auto &captureTL = IGF.IGM.getTypeInfoForLowered(blockTy->getCaptureType());
auto blockStorageSize = storageTL.getFixedSize().getValue();
std::string descriptorName = "block_descriptor";
bool initializeWithCopyCanReuse = false;
bool destroyCanReuse = false;
const auto initializeWithCopyEncoding = captureTL.encodeInitializeWithCopy(
IGF.IGM, storageTL.getFixedAlignment(), initializeWithCopyCanReuse);
const auto destroyEncoding =
initializeWithCopyCanReuse
? captureTL.encodeDestroy(IGF.IGM, storageTL.getFixedAlignment(),
destroyCanReuse)
: "";
const bool descriptorCanReuse =
isTriviallyDestroyable || (initializeWithCopyCanReuse && destroyCanReuse);
if (descriptorCanReuse) {
descriptorName += "_" + llvm::to_string(blockStorageSize) + "_";
if (!isTriviallyDestroyable) {
descriptorName +=
llvm::to_string(storageTL.getFixedAlignment().getValue()) + "_";
descriptorName += initializeWithCopyEncoding + "_" + destroyEncoding;
}
auto typeEncoding = getBlockTypeExtendedEncodingString(IGF.IGM, invokeTy);
// Replace occurrences of '@' with '\1'. '@' is reserved on ELF platforms as
// a separator between symbol name and symbol version.
std::replace(typeEncoding.begin(), typeEncoding.end(), '@', '\1');
descriptorName += typeEncoding;
if (auto descriptor = IGF.IGM.getModule()->getNamedValue(descriptorName)) {
return descriptor;
}
}

// Build the block descriptor.
ConstantInitBuilder builder(IGF.IGM);
auto descriptorFields = builder.beginStruct();

const clang::ASTContext &ASTContext = IGF.IGM.getClangASTContext();
llvm::IntegerType *UnsignedLongTy =
llvm::IntegerType::get(IGF.IGM.getLLVMContext(),
ASTContext.getTypeSize(ASTContext.UnsignedLongTy));
descriptorFields.addInt(UnsignedLongTy, 0);
descriptorFields.addInt(UnsignedLongTy, blockStorageSize);

if (!isTriviallyDestroyable) {
// Define the copy and dispose helpers.
descriptorFields.addSignedPointer(
emitBlockCopyHelper(IGF.IGM, blockTy, storageTL),
IGF.getOptions().PointerAuth.BlockHelperFunctionPointers,
PointerAuthEntity::Special::BlockCopyHelper);
descriptorFields.addSignedPointer(
emitBlockDisposeHelper(IGF.IGM, blockTy, storageTL),
IGF.getOptions().PointerAuth.BlockHelperFunctionPointers,
PointerAuthEntity::Special::BlockDisposeHelper);
}

// Build the descriptor signature.
descriptorFields.add(getBlockTypeExtendedEncoding(IGF.IGM, invokeTy));

// Create the descriptor.
auto descriptor = descriptorFields.finishAndCreateGlobal(
descriptorName, IGF.IGM.getPointerAlignment(),
/*constant*/ true,
descriptorCanReuse ? llvm::GlobalValue::LinkOnceODRLinkage
: llvm::GlobalValue::InternalLinkage);
if (descriptorCanReuse) {
if (IGF.IGM.Triple.supportsCOMDAT())
descriptor->setComdat(IGF.IGM.Module.getOrInsertComdat(descriptorName));
descriptor->setVisibility(llvm::GlobalValue::HiddenVisibility);
descriptor->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
}

return descriptor;
}

/// Emit the block header into a block storage slot.
void irgen::emitBlockHeader(IRGenFunction &IGF,
Address storage,
Expand Down Expand Up @@ -2374,42 +2511,11 @@ void irgen::emitBlockHeader(IRGenFunction &IGF,

// Collect the reserved and invoke pointer fields.
auto reserved = llvm::ConstantInt::get(IGF.IGM.Int32Ty, 0);
llvm::Value *invokeVal = llvm::ConstantExpr::getBitCast(invokeFunction,
IGF.IGM.FunctionPtrTy);

// Build the block descriptor.
ConstantInitBuilder builder(IGF.IGM);
auto descriptorFields = builder.beginStruct();

const clang::ASTContext &ASTContext = IGF.IGM.getClangASTContext();
llvm::IntegerType *UnsignedLongTy =
llvm::IntegerType::get(IGF.IGM.getLLVMContext(),
ASTContext.getTypeSize(ASTContext.UnsignedLongTy));
descriptorFields.addInt(UnsignedLongTy, 0);
descriptorFields.addInt(UnsignedLongTy,
storageTL.getFixedSize().getValue());

if (!isTriviallyDestroyable) {
// Define the copy and dispose helpers.
descriptorFields.addSignedPointer(
emitBlockCopyHelper(IGF.IGM, blockTy, storageTL),
IGF.getOptions().PointerAuth.BlockHelperFunctionPointers,
PointerAuthEntity::Special::BlockCopyHelper);
descriptorFields.addSignedPointer(
emitBlockDisposeHelper(IGF.IGM, blockTy, storageTL),
IGF.getOptions().PointerAuth.BlockHelperFunctionPointers,
PointerAuthEntity::Special::BlockDisposeHelper);
}

// Build the descriptor signature.
descriptorFields.add(getBlockTypeExtendedEncoding(IGF.IGM, invokeTy));

// Create the descriptor.
auto descriptor =
descriptorFields.finishAndCreateGlobal("block_descriptor",
IGF.IGM.getPointerAlignment(),
/*constant*/ true);
llvm::Value *invokeVal =
llvm::ConstantExpr::getBitCast(invokeFunction, IGF.IGM.FunctionPtrTy);

auto descriptor = buildBlockDescriptor(IGF, storageTL, isTriviallyDestroyable,
invokeTy, blockTy);
auto descriptorVal = llvm::ConstantExpr::getBitCast(descriptor,
IGF.IGM.Int8PtrTy);

Expand Down
7 changes: 7 additions & 0 deletions lib/IRGen/GenFunc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,13 @@ namespace irgen {
class ForeignFunctionInfo;
class IRGenFunction;

enum class BlockCaptureInitializeKind {
Store,
};

std::string
getBlockCaptureInitializeKindEncoding(BlockCaptureInitializeKind kind);

/// Project the capture address from on-stack block storage.
Address projectBlockStorageCapture(IRGenFunction &IGF,
Address storageAddr,
Expand Down
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