Have you ever wondered how a compiler works, but you never found courage to find out? Then this project is for you (N.B.: a detailed description is available here).
I have never had the chance to look under the hood either, but one week-end I have decided to to write a translator from the esoteric programming language wend (short for week-end), which I just invented myself, into regular GNU assembly. The goal is to keep the code as tiny as possible, 500-ish lines of python sounds great.
Here is a program that uses virtually all concepts in Wend:
main() { // square root of a fixed-point number // stored in a 32 bit integer variable, shift is the precision int sqrt(int n, int shift) { int x; int x_old; int n_one; if n > 2147483647/shift { // pay attention to potential overflows return 2 * sqrt(n / 4, shift); } x = shift; // initial guess 1.0, can do better, but oh well n_one = n * shift; // need to compensate for fixp division while true { x_old = x; x = (x + n_one / x) / 2; if abs(x - x_old) <= 1 { return x; } } } int abs(int x) { if x < 0 { return -x; } else { return x; } } // 25735 is approximately equal to pi * 8192; // expected value of the output is sqrt(pi) * 8192 approx 14519 println sqrt(25735, 8192); }
make testIt is so dull to compute Fibonacci numbers, so here are more eyecandy examples for our compiler, check test-programs/gfx/*.wend files.
make gfx