forked from OSchip/llvm-project
831 lines
28 KiB
C++
831 lines
28 KiB
C++
//===--- SwiftCallingConv.cpp - Lowering for the Swift calling convention -===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Implementation of the abstract lowering for the Swift calling convention.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "clang/CodeGen/SwiftCallingConv.h"
|
|
#include "clang/Basic/TargetInfo.h"
|
|
#include "CodeGenModule.h"
|
|
#include "TargetInfo.h"
|
|
|
|
using namespace clang;
|
|
using namespace CodeGen;
|
|
using namespace swiftcall;
|
|
|
|
static const SwiftABIInfo &getSwiftABIInfo(CodeGenModule &CGM) {
|
|
return cast<SwiftABIInfo>(CGM.getTargetCodeGenInfo().getABIInfo());
|
|
}
|
|
|
|
static bool isPowerOf2(unsigned n) {
|
|
return n == (n & -n);
|
|
}
|
|
|
|
/// Given two types with the same size, try to find a common type.
|
|
static llvm::Type *getCommonType(llvm::Type *first, llvm::Type *second) {
|
|
assert(first != second);
|
|
|
|
// Allow pointers to merge with integers, but prefer the integer type.
|
|
if (first->isIntegerTy()) {
|
|
if (second->isPointerTy()) return first;
|
|
} else if (first->isPointerTy()) {
|
|
if (second->isIntegerTy()) return second;
|
|
if (second->isPointerTy()) return first;
|
|
|
|
// Allow two vectors to be merged (given that they have the same size).
|
|
// This assumes that we never have two different vector register sets.
|
|
} else if (auto firstVecTy = dyn_cast<llvm::VectorType>(first)) {
|
|
if (auto secondVecTy = dyn_cast<llvm::VectorType>(second)) {
|
|
if (auto commonTy = getCommonType(firstVecTy->getElementType(),
|
|
secondVecTy->getElementType())) {
|
|
return (commonTy == firstVecTy->getElementType() ? first : second);
|
|
}
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
static CharUnits getTypeStoreSize(CodeGenModule &CGM, llvm::Type *type) {
|
|
return CharUnits::fromQuantity(CGM.getDataLayout().getTypeStoreSize(type));
|
|
}
|
|
|
|
void SwiftAggLowering::addTypedData(QualType type, CharUnits begin) {
|
|
// Deal with various aggregate types as special cases:
|
|
|
|
// Record types.
|
|
if (auto recType = type->getAs<RecordType>()) {
|
|
addTypedData(recType->getDecl(), begin);
|
|
|
|
// Array types.
|
|
} else if (type->isArrayType()) {
|
|
// Incomplete array types (flexible array members?) don't provide
|
|
// data to lay out, and the other cases shouldn't be possible.
|
|
auto arrayType = CGM.getContext().getAsConstantArrayType(type);
|
|
if (!arrayType) return;
|
|
|
|
QualType eltType = arrayType->getElementType();
|
|
auto eltSize = CGM.getContext().getTypeSizeInChars(eltType);
|
|
for (uint64_t i = 0, e = arrayType->getSize().getZExtValue(); i != e; ++i) {
|
|
addTypedData(eltType, begin + i * eltSize);
|
|
}
|
|
|
|
// Complex types.
|
|
} else if (auto complexType = type->getAs<ComplexType>()) {
|
|
auto eltType = complexType->getElementType();
|
|
auto eltSize = CGM.getContext().getTypeSizeInChars(eltType);
|
|
auto eltLLVMType = CGM.getTypes().ConvertType(eltType);
|
|
addTypedData(eltLLVMType, begin, begin + eltSize);
|
|
addTypedData(eltLLVMType, begin + eltSize, begin + 2 * eltSize);
|
|
|
|
// Member pointer types.
|
|
} else if (type->getAs<MemberPointerType>()) {
|
|
// Just add it all as opaque.
|
|
addOpaqueData(begin, begin + CGM.getContext().getTypeSizeInChars(type));
|
|
|
|
// Everything else is scalar and should not convert as an LLVM aggregate.
|
|
} else {
|
|
// We intentionally convert as !ForMem because we want to preserve
|
|
// that a type was an i1.
|
|
auto llvmType = CGM.getTypes().ConvertType(type);
|
|
addTypedData(llvmType, begin);
|
|
}
|
|
}
|
|
|
|
void SwiftAggLowering::addTypedData(const RecordDecl *record, CharUnits begin) {
|
|
addTypedData(record, begin, CGM.getContext().getASTRecordLayout(record));
|
|
}
|
|
|
|
void SwiftAggLowering::addTypedData(const RecordDecl *record, CharUnits begin,
|
|
const ASTRecordLayout &layout) {
|
|
// Unions are a special case.
|
|
if (record->isUnion()) {
|
|
for (auto field : record->fields()) {
|
|
if (field->isBitField()) {
|
|
addBitFieldData(field, begin, 0);
|
|
} else {
|
|
addTypedData(field->getType(), begin);
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
// Note that correctness does not rely on us adding things in
|
|
// their actual order of layout; it's just somewhat more efficient
|
|
// for the builder.
|
|
|
|
// With that in mind, add "early" C++ data.
|
|
auto cxxRecord = dyn_cast<CXXRecordDecl>(record);
|
|
if (cxxRecord) {
|
|
// - a v-table pointer, if the class adds its own
|
|
if (layout.hasOwnVFPtr()) {
|
|
addTypedData(CGM.Int8PtrTy, begin);
|
|
}
|
|
|
|
// - non-virtual bases
|
|
for (auto &baseSpecifier : cxxRecord->bases()) {
|
|
if (baseSpecifier.isVirtual()) continue;
|
|
|
|
auto baseRecord = baseSpecifier.getType()->getAsCXXRecordDecl();
|
|
addTypedData(baseRecord, begin + layout.getBaseClassOffset(baseRecord));
|
|
}
|
|
|
|
// - a vbptr if the class adds its own
|
|
if (layout.hasOwnVBPtr()) {
|
|
addTypedData(CGM.Int8PtrTy, begin + layout.getVBPtrOffset());
|
|
}
|
|
}
|
|
|
|
// Add fields.
|
|
for (auto field : record->fields()) {
|
|
auto fieldOffsetInBits = layout.getFieldOffset(field->getFieldIndex());
|
|
if (field->isBitField()) {
|
|
addBitFieldData(field, begin, fieldOffsetInBits);
|
|
} else {
|
|
addTypedData(field->getType(),
|
|
begin + CGM.getContext().toCharUnitsFromBits(fieldOffsetInBits));
|
|
}
|
|
}
|
|
|
|
// Add "late" C++ data:
|
|
if (cxxRecord) {
|
|
// - virtual bases
|
|
for (auto &vbaseSpecifier : cxxRecord->vbases()) {
|
|
auto baseRecord = vbaseSpecifier.getType()->getAsCXXRecordDecl();
|
|
addTypedData(baseRecord, begin + layout.getVBaseClassOffset(baseRecord));
|
|
}
|
|
}
|
|
}
|
|
|
|
void SwiftAggLowering::addBitFieldData(const FieldDecl *bitfield,
|
|
CharUnits recordBegin,
|
|
uint64_t bitfieldBitBegin) {
|
|
assert(bitfield->isBitField());
|
|
auto &ctx = CGM.getContext();
|
|
auto width = bitfield->getBitWidthValue(ctx);
|
|
|
|
// We can ignore zero-width bit-fields.
|
|
if (width == 0) return;
|
|
|
|
// toCharUnitsFromBits rounds down.
|
|
CharUnits bitfieldByteBegin = ctx.toCharUnitsFromBits(bitfieldBitBegin);
|
|
|
|
// Find the offset of the last byte that is partially occupied by the
|
|
// bit-field; since we otherwise expect exclusive ends, the end is the
|
|
// next byte.
|
|
uint64_t bitfieldBitLast = bitfieldBitBegin + width - 1;
|
|
CharUnits bitfieldByteEnd =
|
|
ctx.toCharUnitsFromBits(bitfieldBitLast) + CharUnits::One();
|
|
addOpaqueData(recordBegin + bitfieldByteBegin,
|
|
recordBegin + bitfieldByteEnd);
|
|
}
|
|
|
|
void SwiftAggLowering::addTypedData(llvm::Type *type, CharUnits begin) {
|
|
assert(type && "didn't provide type for typed data");
|
|
addTypedData(type, begin, begin + getTypeStoreSize(CGM, type));
|
|
}
|
|
|
|
void SwiftAggLowering::addTypedData(llvm::Type *type,
|
|
CharUnits begin, CharUnits end) {
|
|
assert(type && "didn't provide type for typed data");
|
|
assert(getTypeStoreSize(CGM, type) == end - begin);
|
|
|
|
// Legalize vector types.
|
|
if (auto vecTy = dyn_cast<llvm::VectorType>(type)) {
|
|
SmallVector<llvm::Type*, 4> componentTys;
|
|
legalizeVectorType(CGM, end - begin, vecTy, componentTys);
|
|
assert(componentTys.size() >= 1);
|
|
|
|
// Walk the initial components.
|
|
for (size_t i = 0, e = componentTys.size(); i != e - 1; ++i) {
|
|
llvm::Type *componentTy = componentTys[i];
|
|
auto componentSize = getTypeStoreSize(CGM, componentTy);
|
|
assert(componentSize < end - begin);
|
|
addLegalTypedData(componentTy, begin, begin + componentSize);
|
|
begin += componentSize;
|
|
}
|
|
|
|
return addLegalTypedData(componentTys.back(), begin, end);
|
|
}
|
|
|
|
// Legalize integer types.
|
|
if (auto intTy = dyn_cast<llvm::IntegerType>(type)) {
|
|
if (!isLegalIntegerType(CGM, intTy))
|
|
return addOpaqueData(begin, end);
|
|
}
|
|
|
|
// All other types should be legal.
|
|
return addLegalTypedData(type, begin, end);
|
|
}
|
|
|
|
void SwiftAggLowering::addLegalTypedData(llvm::Type *type,
|
|
CharUnits begin, CharUnits end) {
|
|
// Require the type to be naturally aligned.
|
|
if (!begin.isZero() && !begin.isMultipleOf(getNaturalAlignment(CGM, type))) {
|
|
|
|
// Try splitting vector types.
|
|
if (auto vecTy = dyn_cast<llvm::VectorType>(type)) {
|
|
auto split = splitLegalVectorType(CGM, end - begin, vecTy);
|
|
auto eltTy = split.first;
|
|
auto numElts = split.second;
|
|
|
|
auto eltSize = (end - begin) / numElts;
|
|
assert(eltSize == getTypeStoreSize(CGM, eltTy));
|
|
for (size_t i = 0, e = numElts; i != e; ++i) {
|
|
addLegalTypedData(eltTy, begin, begin + eltSize);
|
|
begin += eltSize;
|
|
}
|
|
assert(begin == end);
|
|
return;
|
|
}
|
|
|
|
return addOpaqueData(begin, end);
|
|
}
|
|
|
|
addEntry(type, begin, end);
|
|
}
|
|
|
|
void SwiftAggLowering::addEntry(llvm::Type *type,
|
|
CharUnits begin, CharUnits end) {
|
|
assert((!type ||
|
|
(!isa<llvm::StructType>(type) && !isa<llvm::ArrayType>(type))) &&
|
|
"cannot add aggregate-typed data");
|
|
assert(!type || begin.isMultipleOf(getNaturalAlignment(CGM, type)));
|
|
|
|
// Fast path: we can just add entries to the end.
|
|
if (Entries.empty() || Entries.back().End <= begin) {
|
|
Entries.push_back({begin, end, type});
|
|
return;
|
|
}
|
|
|
|
// Find the first existing entry that ends after the start of the new data.
|
|
// TODO: do a binary search if Entries is big enough for it to matter.
|
|
size_t index = Entries.size() - 1;
|
|
while (index != 0) {
|
|
if (Entries[index - 1].End <= begin) break;
|
|
--index;
|
|
}
|
|
|
|
// The entry ends after the start of the new data.
|
|
// If the entry starts after the end of the new data, there's no conflict.
|
|
if (Entries[index].Begin >= end) {
|
|
// This insertion is potentially O(n), but the way we generally build
|
|
// these layouts makes that unlikely to matter: we'd need a union of
|
|
// several very large types.
|
|
Entries.insert(Entries.begin() + index, {begin, end, type});
|
|
return;
|
|
}
|
|
|
|
// Otherwise, the ranges overlap. The new range might also overlap
|
|
// with later ranges.
|
|
restartAfterSplit:
|
|
|
|
// Simplest case: an exact overlap.
|
|
if (Entries[index].Begin == begin && Entries[index].End == end) {
|
|
// If the types match exactly, great.
|
|
if (Entries[index].Type == type) return;
|
|
|
|
// If either type is opaque, make the entry opaque and return.
|
|
if (Entries[index].Type == nullptr) {
|
|
return;
|
|
} else if (type == nullptr) {
|
|
Entries[index].Type = nullptr;
|
|
return;
|
|
}
|
|
|
|
// If they disagree in an ABI-agnostic way, just resolve the conflict
|
|
// arbitrarily.
|
|
if (auto entryType = getCommonType(Entries[index].Type, type)) {
|
|
Entries[index].Type = entryType;
|
|
return;
|
|
}
|
|
|
|
// Otherwise, make the entry opaque.
|
|
Entries[index].Type = nullptr;
|
|
return;
|
|
}
|
|
|
|
// Okay, we have an overlapping conflict of some sort.
|
|
|
|
// If we have a vector type, split it.
|
|
if (auto vecTy = dyn_cast_or_null<llvm::VectorType>(type)) {
|
|
auto eltTy = vecTy->getElementType();
|
|
CharUnits eltSize = (end - begin) / vecTy->getNumElements();
|
|
assert(eltSize == getTypeStoreSize(CGM, eltTy));
|
|
for (unsigned i = 0, e = vecTy->getNumElements(); i != e; ++i) {
|
|
addEntry(eltTy, begin, begin + eltSize);
|
|
begin += eltSize;
|
|
}
|
|
assert(begin == end);
|
|
return;
|
|
}
|
|
|
|
// If the entry is a vector type, split it and try again.
|
|
if (Entries[index].Type && Entries[index].Type->isVectorTy()) {
|
|
splitVectorEntry(index);
|
|
goto restartAfterSplit;
|
|
}
|
|
|
|
// Okay, we have no choice but to make the existing entry opaque.
|
|
|
|
Entries[index].Type = nullptr;
|
|
|
|
// Stretch the start of the entry to the beginning of the range.
|
|
if (begin < Entries[index].Begin) {
|
|
Entries[index].Begin = begin;
|
|
assert(index == 0 || begin >= Entries[index - 1].End);
|
|
}
|
|
|
|
// Stretch the end of the entry to the end of the range; but if we run
|
|
// into the start of the next entry, just leave the range there and repeat.
|
|
while (end > Entries[index].End) {
|
|
assert(Entries[index].Type == nullptr);
|
|
|
|
// If the range doesn't overlap the next entry, we're done.
|
|
if (index == Entries.size() - 1 || end <= Entries[index + 1].Begin) {
|
|
Entries[index].End = end;
|
|
break;
|
|
}
|
|
|
|
// Otherwise, stretch to the start of the next entry.
|
|
Entries[index].End = Entries[index + 1].Begin;
|
|
|
|
// Continue with the next entry.
|
|
index++;
|
|
|
|
// This entry needs to be made opaque if it is not already.
|
|
if (Entries[index].Type == nullptr)
|
|
continue;
|
|
|
|
// Split vector entries unless we completely subsume them.
|
|
if (Entries[index].Type->isVectorTy() &&
|
|
end < Entries[index].End) {
|
|
splitVectorEntry(index);
|
|
}
|
|
|
|
// Make the entry opaque.
|
|
Entries[index].Type = nullptr;
|
|
}
|
|
}
|
|
|
|
/// Replace the entry of vector type at offset 'index' with a sequence
|
|
/// of its component vectors.
|
|
void SwiftAggLowering::splitVectorEntry(unsigned index) {
|
|
auto vecTy = cast<llvm::VectorType>(Entries[index].Type);
|
|
auto split = splitLegalVectorType(CGM, Entries[index].getWidth(), vecTy);
|
|
|
|
auto eltTy = split.first;
|
|
CharUnits eltSize = getTypeStoreSize(CGM, eltTy);
|
|
auto numElts = split.second;
|
|
Entries.insert(Entries.begin() + index + 1, numElts - 1, StorageEntry());
|
|
|
|
CharUnits begin = Entries[index].Begin;
|
|
for (unsigned i = 0; i != numElts; ++i) {
|
|
Entries[index].Type = eltTy;
|
|
Entries[index].Begin = begin;
|
|
Entries[index].End = begin + eltSize;
|
|
begin += eltSize;
|
|
}
|
|
}
|
|
|
|
/// Given a power-of-two unit size, return the offset of the aligned unit
|
|
/// of that size which contains the given offset.
|
|
///
|
|
/// In other words, round down to the nearest multiple of the unit size.
|
|
static CharUnits getOffsetAtStartOfUnit(CharUnits offset, CharUnits unitSize) {
|
|
assert(isPowerOf2(unitSize.getQuantity()));
|
|
auto unitMask = ~(unitSize.getQuantity() - 1);
|
|
return CharUnits::fromQuantity(offset.getQuantity() & unitMask);
|
|
}
|
|
|
|
static bool areBytesInSameUnit(CharUnits first, CharUnits second,
|
|
CharUnits chunkSize) {
|
|
return getOffsetAtStartOfUnit(first, chunkSize)
|
|
== getOffsetAtStartOfUnit(second, chunkSize);
|
|
}
|
|
|
|
void SwiftAggLowering::finish() {
|
|
if (Entries.empty()) {
|
|
Finished = true;
|
|
return;
|
|
}
|
|
|
|
// We logically split the layout down into a series of chunks of this size,
|
|
// which is generally the size of a pointer.
|
|
const CharUnits chunkSize = getMaximumVoluntaryIntegerSize(CGM);
|
|
|
|
// First pass: if two entries share a chunk, make them both opaque
|
|
// and stretch one to meet the next.
|
|
bool hasOpaqueEntries = (Entries[0].Type == nullptr);
|
|
for (size_t i = 1, e = Entries.size(); i != e; ++i) {
|
|
if (areBytesInSameUnit(Entries[i - 1].End - CharUnits::One(),
|
|
Entries[i].Begin, chunkSize)) {
|
|
Entries[i - 1].Type = nullptr;
|
|
Entries[i].Type = nullptr;
|
|
Entries[i - 1].End = Entries[i].Begin;
|
|
hasOpaqueEntries = true;
|
|
|
|
} else if (Entries[i].Type == nullptr) {
|
|
hasOpaqueEntries = true;
|
|
}
|
|
}
|
|
|
|
// The rest of the algorithm leaves non-opaque entries alone, so if we
|
|
// have no opaque entries, we're done.
|
|
if (!hasOpaqueEntries) {
|
|
Finished = true;
|
|
return;
|
|
}
|
|
|
|
// Okay, move the entries to a temporary and rebuild Entries.
|
|
auto orig = std::move(Entries);
|
|
assert(Entries.empty());
|
|
|
|
for (size_t i = 0, e = orig.size(); i != e; ++i) {
|
|
// Just copy over non-opaque entries.
|
|
if (orig[i].Type != nullptr) {
|
|
Entries.push_back(orig[i]);
|
|
continue;
|
|
}
|
|
|
|
// Scan forward to determine the full extent of the next opaque range.
|
|
// We know from the first pass that only contiguous ranges will overlap
|
|
// the same aligned chunk.
|
|
auto begin = orig[i].Begin;
|
|
auto end = orig[i].End;
|
|
while (i + 1 != e &&
|
|
orig[i + 1].Type == nullptr &&
|
|
end == orig[i + 1].Begin) {
|
|
end = orig[i + 1].End;
|
|
i++;
|
|
}
|
|
|
|
// Add an entry per intersected chunk.
|
|
do {
|
|
// Find the smallest aligned storage unit in the maximal aligned
|
|
// storage unit containing 'begin' that contains all the bytes in
|
|
// the intersection between the range and this chunk.
|
|
CharUnits localBegin = begin;
|
|
CharUnits chunkBegin = getOffsetAtStartOfUnit(localBegin, chunkSize);
|
|
CharUnits chunkEnd = chunkBegin + chunkSize;
|
|
CharUnits localEnd = std::min(end, chunkEnd);
|
|
|
|
// Just do a simple loop over ever-increasing unit sizes.
|
|
CharUnits unitSize = CharUnits::One();
|
|
CharUnits unitBegin, unitEnd;
|
|
for (; ; unitSize *= 2) {
|
|
assert(unitSize <= chunkSize);
|
|
unitBegin = getOffsetAtStartOfUnit(localBegin, unitSize);
|
|
unitEnd = unitBegin + unitSize;
|
|
if (unitEnd >= localEnd) break;
|
|
}
|
|
|
|
// Add an entry for this unit.
|
|
auto entryTy =
|
|
llvm::IntegerType::get(CGM.getLLVMContext(),
|
|
CGM.getContext().toBits(unitSize));
|
|
Entries.push_back({unitBegin, unitEnd, entryTy});
|
|
|
|
// The next chunk starts where this chunk left off.
|
|
begin = localEnd;
|
|
} while (begin != end);
|
|
}
|
|
|
|
// Okay, finally finished.
|
|
Finished = true;
|
|
}
|
|
|
|
void SwiftAggLowering::enumerateComponents(EnumerationCallback callback) const {
|
|
assert(Finished && "haven't yet finished lowering");
|
|
|
|
for (auto &entry : Entries) {
|
|
callback(entry.Begin, entry.End, entry.Type);
|
|
}
|
|
}
|
|
|
|
std::pair<llvm::StructType*, llvm::Type*>
|
|
SwiftAggLowering::getCoerceAndExpandTypes() const {
|
|
assert(Finished && "haven't yet finished lowering");
|
|
|
|
auto &ctx = CGM.getLLVMContext();
|
|
|
|
if (Entries.empty()) {
|
|
auto type = llvm::StructType::get(ctx);
|
|
return { type, type };
|
|
}
|
|
|
|
SmallVector<llvm::Type*, 8> elts;
|
|
CharUnits lastEnd = CharUnits::Zero();
|
|
bool hasPadding = false;
|
|
bool packed = false;
|
|
for (auto &entry : Entries) {
|
|
if (entry.Begin != lastEnd) {
|
|
auto paddingSize = entry.Begin - lastEnd;
|
|
assert(!paddingSize.isNegative());
|
|
|
|
auto padding = llvm::ArrayType::get(llvm::Type::getInt8Ty(ctx),
|
|
paddingSize.getQuantity());
|
|
elts.push_back(padding);
|
|
hasPadding = true;
|
|
}
|
|
|
|
if (!packed && !entry.Begin.isMultipleOf(
|
|
CharUnits::fromQuantity(
|
|
CGM.getDataLayout().getABITypeAlignment(entry.Type))))
|
|
packed = true;
|
|
|
|
elts.push_back(entry.Type);
|
|
lastEnd = entry.End;
|
|
}
|
|
|
|
// We don't need to adjust 'packed' to deal with possible tail padding
|
|
// because we never do that kind of access through the coercion type.
|
|
auto coercionType = llvm::StructType::get(ctx, elts, packed);
|
|
|
|
llvm::Type *unpaddedType = coercionType;
|
|
if (hasPadding) {
|
|
elts.clear();
|
|
for (auto &entry : Entries) {
|
|
elts.push_back(entry.Type);
|
|
}
|
|
if (elts.size() == 1) {
|
|
unpaddedType = elts[0];
|
|
} else {
|
|
unpaddedType = llvm::StructType::get(ctx, elts, /*packed*/ false);
|
|
}
|
|
} else if (Entries.size() == 1) {
|
|
unpaddedType = Entries[0].Type;
|
|
}
|
|
|
|
return { coercionType, unpaddedType };
|
|
}
|
|
|
|
bool SwiftAggLowering::shouldPassIndirectly(bool asReturnValue) const {
|
|
assert(Finished && "haven't yet finished lowering");
|
|
|
|
// Empty types don't need to be passed indirectly.
|
|
if (Entries.empty()) return false;
|
|
|
|
CharUnits totalSize = Entries.back().End;
|
|
|
|
// Avoid copying the array of types when there's just a single element.
|
|
if (Entries.size() == 1) {
|
|
return getSwiftABIInfo(CGM).shouldPassIndirectlyForSwift(totalSize,
|
|
Entries.back().Type,
|
|
asReturnValue);
|
|
}
|
|
|
|
SmallVector<llvm::Type*, 8> componentTys;
|
|
componentTys.reserve(Entries.size());
|
|
for (auto &entry : Entries) {
|
|
componentTys.push_back(entry.Type);
|
|
}
|
|
return getSwiftABIInfo(CGM).shouldPassIndirectlyForSwift(totalSize,
|
|
componentTys,
|
|
asReturnValue);
|
|
}
|
|
|
|
CharUnits swiftcall::getMaximumVoluntaryIntegerSize(CodeGenModule &CGM) {
|
|
// Currently always the size of an ordinary pointer.
|
|
return CGM.getContext().toCharUnitsFromBits(
|
|
CGM.getContext().getTargetInfo().getPointerWidth(0));
|
|
}
|
|
|
|
CharUnits swiftcall::getNaturalAlignment(CodeGenModule &CGM, llvm::Type *type) {
|
|
// For Swift's purposes, this is always just the store size of the type
|
|
// rounded up to a power of 2.
|
|
auto size = (unsigned long long) getTypeStoreSize(CGM, type).getQuantity();
|
|
if (!isPowerOf2(size)) {
|
|
size = 1ULL << (llvm::findLastSet(size, llvm::ZB_Undefined) + 1);
|
|
}
|
|
assert(size >= CGM.getDataLayout().getABITypeAlignment(type));
|
|
return CharUnits::fromQuantity(size);
|
|
}
|
|
|
|
bool swiftcall::isLegalIntegerType(CodeGenModule &CGM,
|
|
llvm::IntegerType *intTy) {
|
|
auto size = intTy->getBitWidth();
|
|
switch (size) {
|
|
case 1:
|
|
case 8:
|
|
case 16:
|
|
case 32:
|
|
case 64:
|
|
// Just assume that the above are always legal.
|
|
return true;
|
|
|
|
case 128:
|
|
return CGM.getContext().getTargetInfo().hasInt128Type();
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
bool swiftcall::isLegalVectorType(CodeGenModule &CGM, CharUnits vectorSize,
|
|
llvm::VectorType *vectorTy) {
|
|
return isLegalVectorType(CGM, vectorSize, vectorTy->getElementType(),
|
|
vectorTy->getNumElements());
|
|
}
|
|
|
|
bool swiftcall::isLegalVectorType(CodeGenModule &CGM, CharUnits vectorSize,
|
|
llvm::Type *eltTy, unsigned numElts) {
|
|
assert(numElts > 1 && "illegal vector length");
|
|
return getSwiftABIInfo(CGM)
|
|
.isLegalVectorTypeForSwift(vectorSize, eltTy, numElts);
|
|
}
|
|
|
|
std::pair<llvm::Type*, unsigned>
|
|
swiftcall::splitLegalVectorType(CodeGenModule &CGM, CharUnits vectorSize,
|
|
llvm::VectorType *vectorTy) {
|
|
auto numElts = vectorTy->getNumElements();
|
|
auto eltTy = vectorTy->getElementType();
|
|
|
|
// Try to split the vector type in half.
|
|
if (numElts >= 4 && isPowerOf2(numElts)) {
|
|
if (isLegalVectorType(CGM, vectorSize / 2, eltTy, numElts / 2))
|
|
return {llvm::VectorType::get(eltTy, numElts / 2), 2};
|
|
}
|
|
|
|
return {eltTy, numElts};
|
|
}
|
|
|
|
void swiftcall::legalizeVectorType(CodeGenModule &CGM, CharUnits origVectorSize,
|
|
llvm::VectorType *origVectorTy,
|
|
llvm::SmallVectorImpl<llvm::Type*> &components) {
|
|
// If it's already a legal vector type, use it.
|
|
if (isLegalVectorType(CGM, origVectorSize, origVectorTy)) {
|
|
components.push_back(origVectorTy);
|
|
return;
|
|
}
|
|
|
|
// Try to split the vector into legal subvectors.
|
|
auto numElts = origVectorTy->getNumElements();
|
|
auto eltTy = origVectorTy->getElementType();
|
|
assert(numElts != 1);
|
|
|
|
// The largest size that we're still considering making subvectors of.
|
|
// Always a power of 2.
|
|
unsigned logCandidateNumElts = llvm::findLastSet(numElts, llvm::ZB_Undefined);
|
|
unsigned candidateNumElts = 1U << logCandidateNumElts;
|
|
assert(candidateNumElts <= numElts && candidateNumElts * 2 > numElts);
|
|
|
|
// Minor optimization: don't check the legality of this exact size twice.
|
|
if (candidateNumElts == numElts) {
|
|
logCandidateNumElts--;
|
|
candidateNumElts >>= 1;
|
|
}
|
|
|
|
CharUnits eltSize = (origVectorSize / numElts);
|
|
CharUnits candidateSize = eltSize * candidateNumElts;
|
|
|
|
// The sensibility of this algorithm relies on the fact that we never
|
|
// have a legal non-power-of-2 vector size without having the power of 2
|
|
// also be legal.
|
|
while (logCandidateNumElts > 0) {
|
|
assert(candidateNumElts == 1U << logCandidateNumElts);
|
|
assert(candidateNumElts <= numElts);
|
|
assert(candidateSize == eltSize * candidateNumElts);
|
|
|
|
// Skip illegal vector sizes.
|
|
if (!isLegalVectorType(CGM, candidateSize, eltTy, candidateNumElts)) {
|
|
logCandidateNumElts--;
|
|
candidateNumElts /= 2;
|
|
candidateSize /= 2;
|
|
continue;
|
|
}
|
|
|
|
// Add the right number of vectors of this size.
|
|
auto numVecs = numElts >> logCandidateNumElts;
|
|
components.append(numVecs, llvm::VectorType::get(eltTy, candidateNumElts));
|
|
numElts -= (numVecs << logCandidateNumElts);
|
|
|
|
if (numElts == 0) return;
|
|
|
|
// It's possible that the number of elements remaining will be legal.
|
|
// This can happen with e.g. <7 x float> when <3 x float> is legal.
|
|
// This only needs to be separately checked if it's not a power of 2.
|
|
if (numElts > 2 && !isPowerOf2(numElts) &&
|
|
isLegalVectorType(CGM, eltSize * numElts, eltTy, numElts)) {
|
|
components.push_back(llvm::VectorType::get(eltTy, numElts));
|
|
return;
|
|
}
|
|
|
|
// Bring vecSize down to something no larger than numElts.
|
|
do {
|
|
logCandidateNumElts--;
|
|
candidateNumElts /= 2;
|
|
candidateSize /= 2;
|
|
} while (candidateNumElts > numElts);
|
|
}
|
|
|
|
// Otherwise, just append a bunch of individual elements.
|
|
components.append(numElts, eltTy);
|
|
}
|
|
|
|
bool swiftcall::shouldPassCXXRecordIndirectly(CodeGenModule &CGM,
|
|
const CXXRecordDecl *record) {
|
|
// Following a recommendation from Richard Smith, pass a C++ type
|
|
// indirectly only if the destructor is non-trivial or *all* of the
|
|
// copy/move constructors are deleted or non-trivial.
|
|
|
|
if (record->hasNonTrivialDestructor())
|
|
return true;
|
|
|
|
// It would be nice if this were summarized on the CXXRecordDecl.
|
|
for (auto ctor : record->ctors()) {
|
|
if (ctor->isCopyOrMoveConstructor() && !ctor->isDeleted() &&
|
|
ctor->isTrivial()) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static ABIArgInfo classifyExpandedType(SwiftAggLowering &lowering,
|
|
bool forReturn,
|
|
CharUnits alignmentForIndirect) {
|
|
if (lowering.empty()) {
|
|
return ABIArgInfo::getIgnore();
|
|
} else if (lowering.shouldPassIndirectly(forReturn)) {
|
|
return ABIArgInfo::getIndirect(alignmentForIndirect, /*byval*/ false);
|
|
} else {
|
|
auto types = lowering.getCoerceAndExpandTypes();
|
|
return ABIArgInfo::getCoerceAndExpand(types.first, types.second);
|
|
}
|
|
}
|
|
|
|
static ABIArgInfo classifyType(CodeGenModule &CGM, CanQualType type,
|
|
bool forReturn) {
|
|
if (auto recordType = dyn_cast<RecordType>(type)) {
|
|
auto record = recordType->getDecl();
|
|
auto &layout = CGM.getContext().getASTRecordLayout(record);
|
|
|
|
if (auto cxxRecord = dyn_cast<CXXRecordDecl>(record)) {
|
|
if (shouldPassCXXRecordIndirectly(CGM, cxxRecord))
|
|
return ABIArgInfo::getIndirect(layout.getAlignment(), /*byval*/ false);
|
|
}
|
|
|
|
SwiftAggLowering lowering(CGM);
|
|
lowering.addTypedData(recordType->getDecl(), CharUnits::Zero(), layout);
|
|
lowering.finish();
|
|
|
|
return classifyExpandedType(lowering, forReturn, layout.getAlignment());
|
|
}
|
|
|
|
// Just assume that all of our target ABIs can support returning at least
|
|
// two integer or floating-point values.
|
|
if (isa<ComplexType>(type)) {
|
|
return (forReturn ? ABIArgInfo::getDirect() : ABIArgInfo::getExpand());
|
|
}
|
|
|
|
// Vector types may need to be legalized.
|
|
if (isa<VectorType>(type)) {
|
|
SwiftAggLowering lowering(CGM);
|
|
lowering.addTypedData(type, CharUnits::Zero());
|
|
lowering.finish();
|
|
|
|
CharUnits alignment = CGM.getContext().getTypeAlignInChars(type);
|
|
return classifyExpandedType(lowering, forReturn, alignment);
|
|
}
|
|
|
|
// Member pointer types need to be expanded, but it's a simple form of
|
|
// expansion that 'Direct' can handle. Note that CanBeFlattened should be
|
|
// true for this to work.
|
|
|
|
// 'void' needs to be ignored.
|
|
if (type->isVoidType()) {
|
|
return ABIArgInfo::getIgnore();
|
|
}
|
|
|
|
// Everything else can be passed directly.
|
|
return ABIArgInfo::getDirect();
|
|
}
|
|
|
|
ABIArgInfo swiftcall::classifyReturnType(CodeGenModule &CGM, CanQualType type) {
|
|
return classifyType(CGM, type, /*forReturn*/ true);
|
|
}
|
|
|
|
ABIArgInfo swiftcall::classifyArgumentType(CodeGenModule &CGM,
|
|
CanQualType type) {
|
|
return classifyType(CGM, type, /*forReturn*/ false);
|
|
}
|
|
|
|
void swiftcall::computeABIInfo(CodeGenModule &CGM, CGFunctionInfo &FI) {
|
|
auto &retInfo = FI.getReturnInfo();
|
|
retInfo = classifyReturnType(CGM, FI.getReturnType());
|
|
|
|
for (unsigned i = 0, e = FI.arg_size(); i != e; ++i) {
|
|
auto &argInfo = FI.arg_begin()[i];
|
|
argInfo.info = classifyArgumentType(CGM, argInfo.type);
|
|
}
|
|
}
|