11–20 of 79 posts
Obviously self modifying code would be hard to handle, but every other case ought to work, and the auto-vectorization ought to do amazing things to some loop-heavy code.
It would be interesting to compare this project to simply converting 6502 assembly into LLVM IR, and letting clangs optimization passes work their magic. Obviously self modifying code would be hard to handle, but every other case ought to work, and the auto-vectorization ought to do amazing things to some loop-heavy code.
I'm not 100% sure where the 15 GHz equivalent speed calculation comes from.
The author showed it at the end of the article. It's the "effective speed" reported by some benchmark programs (including calling subroutines, running for loops, iterating on a string, etc). These are simple and trivial programs and can be highly optimized in a simulator on modern x86_64. Real-world programs, like games, is slower, as acknowledged in the article.
My laptop is an ancient 5th gen i5 with 2 keys having fallen off, so games are down in the 2GHz - 3GHz range for me. (Perhaps the missing keys make all the difference.)
I was told by Leonard Tramiel (who was my manager at Atari for a while) that the world record for a production 6502 was 25Mhz. This was demonstrated one Friday evening, some time after the beer fridge had been opened in one of the labs. I don't know if they applied any kind of external cooling, or what the benchmark was. Probably it was "keep cranking up the clock until pins stop wiggling or smoke comes out." Not ver…
It would be interesting to compare this project to simply converting 6502 assembly into LLVM IR, and letting clangs optimization passes work their magic. Obviously self modifying code would be hard to handle, but every other case ought to work, and the auto-vectorization ought to do amazing things to some loop-heavy code.
I agree it'd be wonderful to see auto-vectorization! Obviously, 6502 code does things 1 byte at a time so even adding 32-bit integers is painful. Auto-upgrade of those loops to 32-bit variants would be amazing.
It's an interesting article, but... Better title: Clocking a 6502 Simulator to 15 GHz. There are multiple efforts to recreate the physical 6502 CPU on modern hardware, this is not one of them and should not be confused with that.
I was told by Leonard Tramiel (who was my manager at Atari for a while) that the world record for a production 6502 was 25Mhz. This was demonstrated one Friday evening, some time after the beer fridge had been opened in one of the labs. I don't know if they applied any kind of external cooling, or what the benchmark was. Probably it was "keep cranking up the clock until pins stop wiggling or smoke comes out." Not ver…
"until pins stop wiggling"?
X86 ... not x64
I think this article gets a pass.
It's an interesting article, but... Better title: Clocking a 6502 Simulator to 15 GHz. There are multiple efforts to recreate the physical 6502 CPU on modern hardware, this is not one of them and should not be confused with that.