Best 68040 emulator

[jotd]

Originally Posted by dirkwhoffmann

Hi Jotd. I'm excited to read that you've build a test program which runs Musashi against Basilisk. I am doing exactly the same thing with Moira (which is the CPU powering vAmiga). What I did is to implement a "tesrunner" that iterates over all opcodes and executes them with random register and memory values both with Moira and Musashi. In runs in an endless loop until a mismatch is found. Is your testing code (Basilisk vs. Musashi) available in some public repo? If so, I could probably add Basilisk as another "reference core" to the Moira test runner without having to dig too deep into the Basilisk / UAE sources. Running all three cores against each other might reveal some more bugs in Musashi (and my own CPU).

My comparator didn't work like that. It executed a complex batch run of the application I was trying to emulate and saved the results. So it's not exhaustive. Plus Basilisk UAE core was good but old and probably contained bugs (I fixed an obscure TRAPcc stackframe issue plus a couple others, funny enough Musashi and even MAME had that bug) that WinUAE fixed in the meantime.

Something that could work would be to run Toni Wilen's cpu_tester on vamos. cpu_tester is an amiga executable requiring some amiga OS calls (that vamos probably runs).

In the meantime I also have backported some fixes made in MAME. bitfield instructions were fixed, binary decimal as well, more FPU modes...
MAME = musashi core but then heavily refactored to be integrated in MAME types & architecture. Backports need a lot of search/replace to rollback the MAME changes.

[dirkwhoffmann]

Thanks for the clarifications! I am a big fan of cpu_tester already. What I did with my own CPU core (Moira) was to first run it against Musashi as described in my previous post. After completing this first stage, I integrated it into vAmiga and run cputester in my emulator. This approach worked very well and resulted in an accurate and reliable CPU core. Recently, I've decided to add 68010 / 020 support to Moira (the current version only supports the M68000) and I am trying to repeat my Musashi / cpu_tester approach.