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[ADT] Allow llvm::hash_code as DenseMap key.
ClosedPublic

Authored by sammccall on Jun 20 2018, 4:49 AM.

Reviewers

ioeric

Commits

Summary

This is useful when hash collisions are unlikely and acceptable, e.g. in clangd
completion ranking.

lgtm

This revision is now accepted and ready to land.Jun 20 2018, 4:54 AM

This revision was automatically updated to reflect the committed changes.

Path

Size

llvm/

trunk/

include/

llvm/

ADT/

7 lines

Show First 20 Lines • Show All 256 Lines • ▼ Show 20 Lines	static bool isEqual(ArrayRef<T> LHS, ArrayRef<T> RHS) {
if (RHS.data() == getEmptyKey().data())		if (RHS.data() == getEmptyKey().data())
return LHS.data() == getEmptyKey().data();		return LHS.data() == getEmptyKey().data();
if (RHS.data() == getTombstoneKey().data())		if (RHS.data() == getTombstoneKey().data())
return LHS.data() == getTombstoneKey().data();		return LHS.data() == getTombstoneKey().data();
return LHS == RHS;		return LHS == RHS;
}		}
};		};

		template <> struct DenseMapInfo<hash_code> {
		static inline hash_code getEmptyKey() { return hash_code(-1); }
		static inline hash_code getTombstoneKey() { return hash_code(-2); }
		static unsigned getHashValue(hash_code val) { return val; }
		static bool isEqual(hash_code LHS, hash_code RHS) { return LHS == RHS; }
		};

} // end namespace llvm		} // end namespace llvm

#endif // LLVM_ADT_DENSEMAPINFO_H		#endif // LLVM_ADT_DENSEMAPINFO_H