Let's try tcc as our C compiler, at least for the start of the
Exercism v3 beta period. It has much faster compile times than gcc,
and the C compilation time is a critical factor in maximizing
responsiveness when running the tests via the online editor. This commit
probably reduces the compilation time of the average solution by between
1 and 5 seconds.
Comparing some local compilation times on a typical laptop:
File
Compilation time, gcc
Compilation time, tcc
hello_world.nim
0.6 s
0.2 s
gigasecond.nim
1.0 s
0.6 s
meetup.nim
1.0 s
0.6 s
test_hello_world.nim
2.0 s
0.9 s
test_gigasecond.nim
2.2 s
0.9 s
test_meetup.nim
4.8 s
1.2 s
Each timing is the wall-clock running time of a command that begins
with, respectively:
nim c -f --cc:gcc
nim c -f --cc:tcc
The -f option means that no compilation cache is used.
As a bonus, the image is much smaller too.
Image size before this commit: 87.48 MB
Image size with this commit: 26.74 MB
This (uncompressed) size is getting pretty close to the theoretical
minimum for a Nim image, given that we use approximately:
5 MB for the Alpine parent image
5 MB for the Nim compiler
5 MB for the Nim standard library
10 MB for musl libc
1 MB in total for PCRE and tcc
tcc is good for non-optimized builds, which is exactly our use case.
Generally it works well, especially for simple programs like Exercism
solutions. But in the long-term, Nim will only fully support GCC, Clang
and MSVC.
We might want to use tcc until Nim gains incremental compilation. But
if we run into problems, we can always just revert this commit before
the release of Exercism v3.
In the future we could:
Add a pre-built nimcache into the image, and make the compiler use
that when compiling every user's solution.
If we keep using tcc: build it from the mob branch, rather than
using the latest release (which is a few years old).
In the long-term, it should be possible for a good Nim solution to run
near-instantly from the online editor.
Let's try
tccas our C compiler, at least for the start of the Exercism v3 beta period. It has much faster compile times thangcc, and the C compilation time is a critical factor in maximizing responsiveness when running the tests via the online editor. This commit probably reduces the compilation time of the average solution by between 1 and 5 seconds.Comparing some local compilation times on a typical laptop:
gcctcchello_world.nimgigasecond.nimmeetup.nimtest_hello_world.nimtest_gigasecond.nimtest_meetup.nimEach timing is the wall-clock running time of a command that begins with, respectively:
nim c -f --cc:gccnim c -f --cc:tccThe
-foption means that no compilation cache is used.As a bonus, the image is much smaller too.
This (uncompressed) size is getting pretty close to the theoretical minimum for a Nim image, given that we use approximately:
tccis good for non-optimized builds, which is exactly our use case. Generally it works well, especially for simple programs like Exercism solutions. But in the long-term, Nim will only fully support GCC, Clang and MSVC.We might want to use
tccuntil Nim gains incremental compilation. But if we run into problems, we can always just revert this commit before the release of Exercism v3.In the future we could:
nimcacheinto the image, and make the compiler use that when compiling every user's solution.tcc: build it from themobbranch, rather than using the latest release (which is a few years old).In the long-term, it should be possible for a good Nim solution to run near-instantly from the online editor.
The largest files in the image:
The final disk usage in the root directory: