Static Allocation for Compilers

Compilers that stop grabbing memory? Crowd split between 70s trauma and speed hype

TLDR: A dev pitched compilers that pre-allocate memory and stream work in chunks. Commenters split: some warn of wasted space and broken cross-file checks, others recall 70s pain, while a few report speed wins with arenas. It matters for faster, more reliable builds without surprise crashes.

A bold proposal lands: make compilers behave like TigerBeetle and do all memory allocation at startup, then process code in small chunks, streaming results to an “output arena.” Sounds clean and crash-proof? The comments erupted like a popcorn machine.

The loudest pushback screams waste. User delifue argued static allocation means hard limits and empty space everywhere, with the “256-byte string” meme flying around. Cloudhead added that real compilers need cross-file knowledge—think functions calling each other in circles—so you can’t keep just one file in memory and hope types magically line up.

Then the history buffs kicked down the door. Joker_vD reminded everyone that streaming compilers were a 70s thing and “quite painful,” cue mainframe PTSD jokes and “Unix did it first” memes. Meanwhile, pwdisswordfishy poked holes in the math: if outputs grow with your program, how is the processing truly O(1)? Thread instantly devolved into diagram wars.

Not all doom: deivid came in hot with a 2x speed boost using arenas (pre-sized memory pools) in Tiny C Compiler, waving the “practical beats pure” flag. The vibe? Half the crowd sees elegant simplicity and fewer crashes; the other half sees broken type checks, wasted RAM, and a rerun of ancient mistakes. Drama level: spicy.

Key Points

  • TigerBeetle’s “static allocation” means all memory is allocated at startup, with no allocations or deallocations during runtime.
  • The system’s finite message size (1 MiB) enables non-allocating, compositional processing, with data stored on disk.
  • For compilers, fixed upper limits or single arenas either waste memory or risk out-of-memory, making static allocation challenging.
  • A proposed compiler approach sets aside an output arena and processes inputs in finite chunks (e.g., per-file limit such as 4 MiB).
  • Using indexes instead of pointers for output data facilitates persisting results to disk and maintaining O(1) intermediate memory.

Hottest takes

"Static memory allocation requires hardcoding an upper limit of size of everything." — delifue
"Yes, you can dump your IR straight to the disk and then stream it to process further." — Joker_vD
"using arenas sped it up 2x" — deivid
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