Compiler

just-in-time compiler

graph TD
    A[Source Code] --> B[Bytecode / IR]
    B --> C[Interpreter]
    C --> D{Hot Spot?}
    D -->|Yes| E[JIT Compiler]
    D -->|No| C
    E --> F[Native Machine Code]
    F --> G[Execution]
    C --> G

See also: thoughts/jit.py

toy example for branch optimization:

import numpy as np
import numpy.typing as npt
 
cache: list[npt.NDArray[np.float32]] = []
 
 
def dct_jit(x: npt.NDArray[np.float32]) -> npt.NDArray[np.float32]:
  global cache
  x_tuple = tuple(x)
  if x_tuple in cache:
    return cache[x_tuple]
 
  N = len(x)
  result = np.zeros(N)
  for k in range(N):
    sum_val = 0
    for n in range(N):
      sum_val += x[n] * np.cos(np.pi * k * (2 * n + 1) / (2 * N))
    result[k] = sum_val
 
  cache[x_tuple] = result
  return result