Out of curiosity, does Intel's icc compiler see much use? It looks like it uses LLVM these days, but its frontend presumably still needs to handle all of C++'s complexity.
ICC is deprecated and will no longer see a release, but it uses the EDG front-end. Its replacement, ICX (the oneAPI compiler), uses clang as its front-end.
There are essentially only four extant C++ front-end implementations: GCC, Clang, MSVC, and EDG. All other C++ compilers are based on one of these four implementations, or have since gone extinct. (Except maybe Green Hills, but I can't recall anymore if their front-end is still in-house.)
Got it, thanks! I knew that Intel had a compiler for C and C++ from reading blogs about compiler research, but I didn't know any details about its current architecture.
There are essentially only four extant C++ front-end implementations: GCC, Clang, MSVC, and EDG. All other C++ compilers are based on one of these four implementations, or have since gone extinct. (Except maybe Green Hills, but I can't recall anymore if their front-end is still in-house.)