Skip to content

[clang][bytecode] Add some convenience API to BitcastBuffer #169516

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Nov 26, 2025
Merged

[clang][bytecode] Add some convenience API to BitcastBuffer #169516

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
3af793b
[clang][bytecode] Add some convenience API to BitcastBuffer
tbaederr Nov 25, 2025
54376f7
Merge branch 'main' into bitcast-buffer
tbaederr Nov 25, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 13 additions & 0 deletions clang/lib/AST/ByteCode/BitcastBuffer.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -89,6 +89,12 @@ struct BitcastBuffer {
Data = std::make_unique<std::byte[]>(ByteSize);
}

/// Returns the byte at the given offset.
std::byte *atByte(unsigned Offset) {
assert(Offset < FinalBitSize.roundToBytes());
return Data.get() + Offset;
}

/// Returns the buffer size in bits.
Bits size() const { return FinalBitSize; }
Bytes byteSize() const { return FinalBitSize.toBytes(); }
Expand All @@ -113,6 +119,13 @@ struct BitcastBuffer {
std::unique_ptr<std::byte[]> copyBits(Bits BitOffset, Bits BitWidth,
Bits FullBitWidth,
Endian TargetEndianness) const;

/// Dereferences the value at the given offset.
template <typename T> T deref(Bytes Offset) const {
assert(Offset.getQuantity() < FinalBitSize.roundToBytes());
assert((Offset.getQuantity() + sizeof(T)) <= FinalBitSize.roundToBytes());
return *reinterpret_cast<T *>(Data.get() + Offset.getQuantity());
}
};

} // namespace interp
Expand Down
8 changes: 4 additions & 4 deletions clang/lib/AST/ByteCode/InterpBuiltin.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1997,8 +1997,8 @@ static bool interp__builtin_memcmp(InterpState &S, CodePtr OpPC,
for (size_t I = 0; I != CmpSize; I += ElemSize) {
if (IsWide) {
INT_TYPE_SWITCH(*S.getContext().classify(ASTCtx.getWCharType()), {
T A = *reinterpret_cast<T *>(BufferA.Data.get() + I);
T B = *reinterpret_cast<T *>(BufferB.Data.get() + I);
T A = *reinterpret_cast<T *>(BufferA.atByte(I));
T B = *reinterpret_cast<T *>(BufferB.atByte(I));
if (A < B) {
pushInteger(S, -1, Call->getType());
return true;
Expand All @@ -2009,8 +2009,8 @@ static bool interp__builtin_memcmp(InterpState &S, CodePtr OpPC,
}
});
} else {
std::byte A = BufferA.Data[I];
std::byte B = BufferB.Data[I];
std::byte A = BufferA.deref<std::byte>(Bytes(I));
std::byte B = BufferB.deref<std::byte>(Bytes(I));

if (A < B) {
pushInteger(S, -1, Call->getType());
Expand Down