Otherwise, with recent versions of libstdc++, clang can't tell that the
atomic operations are properly aligned, and generates calls to
libatomic. (Actually, because of the use of reinterpret_cast, it wasn't
guaranteed to be aligned, but I think it ended up being aligned in
practice.)
Fixes https://github.com/llvm/llvm-project/issues/54790 , the part where
LLVM failed to build.
Differential Revision: https://reviews.llvm.org/D123872
/// A ghash table cell for deduplicating types from TpiSources.
class GHashCell {
- uint64_t data = 0;
+ // Force "data" to be 64-bit aligned; otherwise, some versions of clang
+ // will generate calls to libatomic when using some versions of libstdc++
+ // on 32-bit targets. (Also, in theory, there could be a target where
+ // new[] doesn't always return an 8-byte-aligned allocation.)
+ alignas(sizeof(uint64_t)) uint64_t data = 0;
public:
GHashCell() = default;