It reads C and writes x86-64 assembly. It compiles real programs: SQLite (about 270,000 lines of C) and the Lua 5.4.7 interpreter. Correctness comes first: a change that miscompiles anything is reverted, whatever it gains. The numbers below come from real runs, not from us.
The referee builds SQLite with this compiler, runs a corpus of SQL scripts against gcc's build, and counts the instructions each workload executes (callgrind, exact) against gcc -O2's. Lower is better; gcc -O2 is the tick at 1.0×.
Small benchmark programs, compiled by this compiler and by gcc -O2. Both must print the same thing. Then the instructions each executes are counted, and one function's assembly is shown from both.
Three runs, each designed and predicted in writing before it ran (the write-ups are in the repository).