An optimizing compiler of SysY, a subset of C. Supported targets are armv7 and risc-v32. (To be accurate, armv7ve and rv32im.)

SysY is the language used by the Collegiate Student System Capability Challenge (Compiler Track) 2021, a compiler contest in China. (contest homepage)

For SysY specification (in Chinese), runtime, and testcases, see here.

README in Chinese

Testcases of the contest consist of two parts: functional testcases and performance testcases. The functional testcases were scored by correctness, and the performance testcases were scored based on the running time of the compiler output. In the contest, we passed all the functional testcases, so did most of the teams in the final round. Our performance score and total score both took the first place.

Here are some test results on the performance testcases of the contest. The test environment is a Raspberry Pi 4B. As a comparison, the performance of the code generated by gcc (Raspbian 8.3.0-6+rpi1) 8.3.0 is also listed.

Arguments for gcc are -march=armv7ve -Ofast.

Test results when automatic parallelization is disabled: no parallelization

Test results when automatic parallelization is enabled (add --enable-loop-parallel to this compiler, -ftree-parallelize-loops=4 to gcc): parallelization

0. Build

mkdir build
cd build
cmake ..
make -j$(nproc)

1. Run

./compiler <source_code>.sy -o <output_asm>.s

Use --set-<key>=<value> to specify key-value pairs. Here are the available options:

Other flags:

Also, remember to link the output with the runtime under runtime/.

doc/intro.pdf
doc/pre.pdf

Kobayashi is a name from the anime Miss Kobayashi's Dragon Maid, and our team name in the contest is Miss Kobayashi's Compiler.