This is an extremely interesting idea, Fred. I had a quick play with it --
my computer is too slow to really let it have a good run at things. I don't
know enough about it yet to make really meaningful suggestions, but I
thought I'd just give you some encouragement to continue development.
Cheers
A
----- Original Message -----
From: "Fred Quimby" <c9r@xxxxxxxxxxx>
To: <stella@xxxxxxxxxxxxxxxxxx>
Sent: Tuesday, May 31, 2005 9:44 PM
Subject: [stella] 6502 superoptimizer update
>I found an amazing number of bugs in the first version of this I posted
>last
> week, and some of them were so bad that the program produced bogus results
> or overlooked results that should have been good. I've attached the
> updated
> version (Alpha 0.02) to this post.
>
> Bugs fixed:
> The program did not set N and Z flags based on initial accumulator value
> Carry flag was inverted in compare operations
> Branches often jumped to wrong target address
> Various other errors in 6502 core
> The "Estimated time" is severely underestimated (actually, it's still not
> particularly accurate)
>
> New feature:
> Still one unbounded immediate, but also up to two bounded immedates
> allowed
> ($00, $01, or $FF, which are probably the most common immediate values
> loaded.)
>
> To do for next version:
> Optimize code for speed!
> Skip tests that rely on undefined flags
> Skip tests that rely on undefined zero-page loads
> Skip tests that store undefined register values
> Stop if it is determined that the input code can be optimized
> Post the source
> Use something other than the gets() function to get stdin
> Add command-line switches to specify:
> - number of unbounded immediates allowed
> - number of bounded immediates
> - number of zero-page addresses
> - Option to limit to a subset of the available instructions (legal
> opcodes,
> common opcodes, etc)
>
> Any other suggestions/comments/criticism?
>
> Archives (includes files) at http://www.biglist.com/lists/stella/archives/
> Unsub & more at http://stella.biglist.com
>
Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://stella.biglist.com
