LLVM is a backend compiler which compiles to backend targets like x86, which have their own compilers. It's hard to say exactly what a compiler is and isn't, because it's compilers all the way down; compilers are made of compilers.
My working definition is a compiler is a program that turns code from one form into another, whether that's machine code, byte code, IR, or some other high level source. It's a broad definition but it covers all the things we call "compilers".
"In computing, a compiler is software that translates computer code written in one programming language (the source language) into another language (the target language)."
"LLVM, also called LLVM Core, is a target-independent optimizer and code generator.[5] It can be used to develop a frontend for any programming language and a backend for any instruction set architecture. LLVM is designed around a language-independent intermediate representation (IR) that serves as a portable, high-level assembly language that can be optimized with a variety of transformations over multiple passes.[6]""
As I correctly said, LLVM is not a compiler, it is a backend target of Rust, C++, etc. compilers. They read source language and generate backend output ... anything from assembly language to C++. Even when Nim uses the C++ backend, C++ is the backend target, even though the generated C++ is fed to a C++ compiler.
> So you have an idiosyncratic definition of compiler that no one else uses.
My definition is supported by your links, so I don't think it's idiosyncratic at all.
> "In computing, a compiler is software that translates computer code written in one programming language (the source language) into another language (the target language)."
That's exactly what I said:
"My working definition is a compiler is a program that turns code from one form into another"
> LLVM... is a target-independent optimizer and code generator.
Code generators are a kind of compiler. The input language is IR, and the output language is machine code. Thus it fits the definition of a compiler you proffered.
> As I correctly said, LLVM is not a compiler, it is a backend target of Rust, C++, etc. compilers.
These things are not mutually exclusive. It can be a target of Rust, C++, etc., but that doesn't make it not a compiler. LLVM being a compiler is supported by both of your wiki links. Your first link lists LLVM under "Notable Compilers and Toolchains". In the second link in the LLVM infobox it reads "Type: Compiler". Nuff said.
Also not relevant since it lacks Nim's mechanisms for integrating the generated code with user-provided C++. You said that you questioned Nim's "fantastic interop" but you have no valid logical reason to ... certainly Rust not having it isn't any sort of argument.
> Rust is being developed for LLVM, a compiler that's also shared with C++.
Not at all relevant (and LLVM is a backend target, not a compiler).