IR: Use DenseSet instead of DenseMap for ConstantUniqueMap; NFC
Use a DenseSet instead of a DenseMap for constants in LLVMContextImpl.
Last time I looked at this was some time before r223588, when
DenseSet<V> had no advantage over DenseMap<V,char>. After r223588,
there's a 50% memory savings.
This is all mechanical. There were little bits of missing API from
DenseSet so I added the trivial implementations:
- iterator::operator++(int)
- template <class LookupKeyT> insert_as(ValueTy, LookupKeyT)
There should be no functionality change, just reduced memory consumption
(this wasn't on a profile or anything; just a cleanup I stumbled on).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265577 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed