4 ms·

Compiling C Programs Into “Mov” Instructions (And Only “Mov” Instructions)

78 points by optimalsolver 5y ago

qweqwweqwe-90i 5y ago
Still the one of the best things ever. The author also has some amazing talks available: https://www.youtube.com/results?search_query=chris+domas https://www.youtube.com/results?search_query=chris+domas
jinseokim 5y ago
Past discussions: https://news.ycombinator.com/item?id=6309631 https://news.ycombinator.com/item?id=6309631 https://news.ycombinator.com/item?id=9751312 https://news.ycombinator.com/item?id=9751312 https://news.ycombinator.com/item?id=12372242 https://news.ycombinator.com/item?id=12372242
mikeytown2 5y ago
Making hardware that'd take advantage of this simple instruction set might have some interesting results.
- anothernewdude 5y ago
  All you need is memory mapping. You map an ALU/whatever to some memory locations. Move your register to the right input addresses, move out the output.
  - p4bl0 5y ago
    For a project in an undergrad (3rd year) computer architecture course we had to invent a netlist language, implement a netlist interpreter, and then write a processor in our own netlist language and write an assembly program for that processor that would output a timer (the idea was to produce something fast enough to update the output each second). With a friend we "invented" exactly what you described. Our original idea started as a joke to make a processor with a single instruction,and when we thought of having registers that would systematically be updated with the results of different operations on two operand registers we understood we could actually do it. So we did. It was a bit tricky and quite slow but it was a lot of fun and we still managed to beat the second at the end =).
    - anothernewdude 5y ago
      Early computers did it a lot more. C64 and the like still had typical instructions, but if you wanted to deal with the video chip, it had lots of sections of memory that you just altered to get the results on screen. Want a character up at the top left? put it's PETSCII code at $0400.
Travis16 5y ago
This is one of the most significant information. And i’m glad reading your article. Thank for sharing. https://www.skylightpaycard.run/ https://www.skylightpaycard.run/
xelxebar 5y ago
Oh boy. If anyone here is coming across Chris Domas (the author of this github) for the first time, you're in for a treat! Some of his talks on youtube are absolutely mind-blowing: DEF CON 26 - Christopher Domas - GOD MODE UNLOCKED Hardware Backdoors in redacted x86: https://invidious.snopyta.org/watch?v=jmTwlEh8L7g https://invidious.snopyta.org/watch?v=jmTwlEh8L7g DEF CON 26 - Christopher Domas - The Ring 0 Facade Awakening the Processors Inner Demons: https://invidious.snopyta.org/watch?v=XH0F9r0siTI https://invidious.snopyta.org/watch?v=XH0F9r0siTI
- jonpalmisc 5y ago
  Domas is incredible — every time I see watch his talks (and they are absolutely worth re-watching) I always think to myself “this guy is /so good/ at what he does”. Sadly he seems to have stopped putting content out after he began working for Intel.
- enlyth 5y ago
  What is snopyta.org? These links don't work for me (403) so I had to manually change them to YouTube
  - xelxebar 5y ago
    It's an invidious[0] instance. Looks like it was down for a bit. You can replace the URL domains with youtube.com and get the same video. Better yet, you can use any alternative invidious instances given at invidio.us. [0]:https://github.com/iv-org/invidious https://github.com/iv-org/invidious
- bogomipz 5y ago
  Unfortunately neither of these links work for me. Might they be available elsewhere or do you or someone else have updated links? The title seem very interesting. Thanks.
  - xelxebar 5y ago
    These links are just to an invidious[0] instance. I guess the instance was temporarily down. It worked when I tried right now. You can also replace the domain with youtube.com and it should work. Better yet, you can try any of the alternative invidious instances listed at invidio.us. Happy hacking! [0]:https://github.com/iv-org/invidious https://github.com/iv-org/invidious
Jyaif 5y ago
Reminds me of Tom Murphy VII's compiler that generates executable that only contain text-friendly ASCII characters: http://tom7.org/abc/ http://tom7.org/abc/
bradrn 5y ago
cf. the Wireworld computer, which also has a construction set consisting of only MOV: https://www.quinapalus.com/wi-index.html https://www.quinapalus.com/wi-index.html

78 points by optimalsolver 5y ago

Still the one of the best things ever. The author also has some amazing talks available: https://www.youtube.com/results?search_query=chris+domas https://www.youtube.com/results?search_query=chris+domas

jinseokim 5y ago

Past discussions: https://news.ycombinator.com/item?id=6309631 https://news.ycombinator.com/item?id=6309631 https://news.ycombinator.com/item?id=9751312 https://news.ycombinator.com/item?id=9751312 https://news.ycombinator.com/item?id=12372242 https://news.ycombinator.com/item?id=12372242

mikeytown2 5y ago

Making hardware that'd take advantage of this simple instruction set might have some interesting results.

anothernewdude 5y ago
All you need is memory mapping. You map an ALU/whatever to some memory locations. Move your register to the right input addresses, move out the output.
- p4bl0 5y ago
  For a project in an undergrad (3rd year) computer architecture course we had to invent a netlist language, implement a netlist interpreter, and then write a processor in our own netlist language and write an assembly program for that processor that would output a timer (the idea was to produce something fast enough to update the output each second). With a friend we "invented" exactly what you described. Our original idea started as a joke to make a processor with a single instruction,and when we thought of having registers that would systematically be updated with the results of different operations on two operand registers we understood we could actually do it. So we did. It was a bit tricky and quite slow but it was a lot of fun and we still managed to beat the second at the end =).
  - anothernewdude 5y ago
    Early computers did it a lot more. C64 and the like still had typical instructions, but if you wanted to deal with the video chip, it had lots of sections of memory that you just altered to get the results on screen. Want a character up at the top left? put it's PETSCII code at $0400.

Travis16 5y ago

This is one of the most significant information. And i’m glad reading your article. Thank for sharing. https://www.skylightpaycard.run/ https://www.skylightpaycard.run/

xelxebar 5y ago

Oh boy. If anyone here is coming across Chris Domas (the author of this github) for the first time, you're in for a treat! Some of his talks on youtube are absolutely mind-blowing: DEF CON 26 - Christopher Domas - GOD MODE UNLOCKED Hardware Backdoors in redacted x86: https://invidious.snopyta.org/watch?v=jmTwlEh8L7g https://invidious.snopyta.org/watch?v=jmTwlEh8L7g DEF CON 26 - Christopher Domas - The Ring 0 Facade Awakening the Processors Inner Demons: https://invidious.snopyta.org/watch?v=XH0F9r0siTI https://invidious.snopyta.org/watch?v=XH0F9r0siTI

jonpalmisc 5y ago
Domas is incredible — every time I see watch his talks (and they are absolutely worth re-watching) I always think to myself “this guy is /so good/ at what he does”. Sadly he seems to have stopped putting content out after he began working for Intel.
enlyth 5y ago
What is snopyta.org? These links don't work for me (403) so I had to manually change them to YouTube
- xelxebar 5y ago
  It's an invidious[0] instance. Looks like it was down for a bit. You can replace the URL domains with youtube.com and get the same video. Better yet, you can use any alternative invidious instances given at invidio.us. [0]:https://github.com/iv-org/invidious https://github.com/iv-org/invidious
bogomipz 5y ago
Unfortunately neither of these links work for me. Might they be available elsewhere or do you or someone else have updated links? The title seem very interesting. Thanks.
- xelxebar 5y ago
  These links are just to an invidious[0] instance. I guess the instance was temporarily down. It worked when I tried right now. You can also replace the domain with youtube.com and it should work. Better yet, you can try any of the alternative invidious instances listed at invidio.us. Happy hacking! [0]:https://github.com/iv-org/invidious https://github.com/iv-org/invidious

Jyaif 5y ago

Reminds me of Tom Murphy VII's compiler that generates executable that only contain text-friendly ASCII characters: http://tom7.org/abc/ http://tom7.org/abc/

bradrn 5y ago

cf. the Wireworld computer, which also has a construction set consisting of only MOV: https://www.quinapalus.com/wi-index.html https://www.quinapalus.com/wi-index.html