Tilde, My LLVM Alternative

Cool. The author has set himself a huge task if he wants to build something like LLVM. An alternative would be to participate in a project with similar goals that is already quite progressed, such as QBE or Eigen (https://github.com/EigenCompilerSuite/) ; both so far lack of optimizers. I consider Eigen very attractive because it supports much more targets and includes assemblers and linkers for all targets. I see the advantage in having a C implementation; Eigen is unfortunately developed in C++17, but I managed to backport the parts I'm using to a moderate C++11 subset (https://github.com/rochus-keller/Eigen). There are different front-ends available, two C compilers among them. And - as mentioned - an optimizer would be great.

EDIT: just found this podcast where the author gives more informations about the project goals and history (at least the beginning of the podcast is interesting): https://www.youtube.com/watch?v=f2khyLEc-Hw

> I believe it's (LLVM) far too slow at compiling and far too big to be fixed from the inside

What are you doing to make sure Tilde does not end up like this?

Chris Lattner seems to have also created an alternative for LLVM - https://mlir.llvm.org/

Because of how the architecture works, LLVM is one of the backends, but it doesn't have to be. Very interesting project, you could do a lot more IR processing before descending to LLVM (if you use that), that way you could give LLVM a lot less to do.

Chris has said LLVM is fast at what it is designed to do - lower IR to machine code. However, because of how convoluted it can get, and the difficulty involved in getting information from some language-specific MIR to LLVM, languages are forced to generate tons upon tons of IR so as to capture every possible detail. Then LLVM is asked to clean up and optimize this IR.

One thing to look out for is the problem of either losing language-specific information when moving from MIR to Low-level IR (be it Tilde or LLVM) or generating too much information, most of it useless.

>I'm calling it Tilde (or TB for tilde backend) and the reasons are pretty simple, i believe it's far too slow at compiling and far too big to be fixed from the inside. It's been 20 years and cruft has built up, time for a "redo".

That put a smile on my face because I remember that was how LLVM was born out of frustration with GCC.

I dont know how the modern GCC and LLVM compares, I remember LLVM was fast but resulting binary were not as optimised, once those optimisation added it became slower. While LLVM was a wake up call to modernise GCC and make it faster. In the end competition made both a lot better.

I believe some industry ( Gaming ) used to swear by VS Studio / MS Compiler / Intel Compiler or languages that depends / prefer the Borland ( What ever they are called now ) compiler. Its been very long since I last looked I am wondering if those two are still used or have we all merged mostly into LLVM / GCC?

Again, somebody who comes to the realization something is seriously wrong with ultra-complex languages in the SDK (c++ and similar).

In other words, since this alternative LLVM is coded in plain and simple C, it is shielded against those who are still not seeing that computer languages with an ultra complex syntax are not the right way to go if if want sane software.

You also have QBE, which with cproc will give you ~70% of latest gcc speed (in my benchmarks on AMD zen2 x86_64).