nw: The speedup is only really gaudy on CPS-3 where the SH-2 is a major percentage of the frame time (800% -> 1250% unthrottled). SKNS games that access spriteram a lot (cyvern) get a decent speedup as well. Saturn/ST-V and Cool Riders are dominated by the rendering in profiles and get around 10% improvement depending on the game.
(nw)
This precalculation seems to be part of OG's "CPU core template", as all CPU
cores written by him do it. It's used to optimize things like onboard serial
ports and high-frequency timers; however, the m6502 and its derivatives have
neither onboard serial ports nor high-frequency timers, and the precalculation
is simply a boat anchor on drivers with 6502-family CPUs and tight interleaving.
mess c64 benchmarks (3.4 GHz Sandy Bridge i5; 64-bit Linux GCC 4.8 build)
before:
[awj@localhost trunk]$ ./mess64 -window -bench 60 c64
Average speed: 238.17% (59 seconds)
[awj@localhost trunk]$ ./mess64 -window -bench 60 c64
Average speed: 236.36% (59 seconds)
after:
[awj@localhost trunk]$ ./mess64 -window -bench 60 c64
Average speed: 279.93% (59 seconds)
[awj@localhost trunk]$ ./mess64 -window -bench 60 c64
Average speed: 279.30% (59 seconds)
[MESS] vtvideo.c): finally fix smooth scrolling (ED084 = 1). See DIAG DISK -> VIDEO TEST -> screen 3 (Rainbow driver - SKIP 0). [Bavarese]
[MESS] atari400.c - Slightly revised Atari XL cartridge loading so that it doesn't crash when loading 8K carts. Confirmed to fix MT#05108. [alegend45]
Description fix from MASH for chihiro.c. (nw)
Update neogeo.xml to take advantage of them.
For regular rom loading we try to autodetect the appropriate endianness and
width by matching the region tag to a device with a device_memory_interface;
this is generally not doable for software lists because the regions are
children of some slot device and thus not siblings of the devices in the root
driver (i.e. "cartslot1:maincpu" rather than "maincpu") So you have to
specify the width and endianness manually for now.
Anyone who has spare time, feel welcome to byteswap every single entry
in megadriv.xml and update them to use this :-)
