CVS commit: src/sys/arch/luna68k/dev

["Tetsuya Isaki" <isaki%netbsd.org@localhost>]

Module Name:    src
Committed By:   isaki
Date:           Sun Sep 25 11:28:40 UTC 2022

Modified Files:
        src/sys/arch/luna68k/dev: lunafb.c omrasops.c omrasopsvar.h

Log Message:
lunafb: Improve drawing performance using VRAM ROP features.
- Drawing a character on 4bpp normally needs 4 times writes, but by using
  VRAM ROP actively, it can be reduced to write only once.
  The same goes for copyrows.  If the whole row consists of only two colors
  (one foreground and one background), it can be copied by reading once and
  writing once, regardless of the number of planes.  Only if the row consists
  of more than two colors, it will be copied plane by plane.
- On 8bpp board, it acts as 4bpp (16 colors).
- On 4bpp board on the real LUNA-I(68030/20MHz), monochrome scroll is about
  4 times faster even without asm.  Using asm improves it by additional 5%
  (asm is enabled by default).
- By tsutsui@-san's report, even color scroll is about about 2 times faster
  on his 8bpp board on the real LUNA-II(68040).
This was first developped by Y.Sugahara back in late 2019, and was modified
a lot by me in 2022.
http://mail-index.netbsd.org/port-luna68k/2022/09/23/msg000072.html


To generate a diff of this commit:
cvs rdiff -u -r1.46 -r1.47 src/sys/arch/luna68k/dev/lunafb.c
cvs rdiff -u -r1.22 -r1.23 src/sys/arch/luna68k/dev/omrasops.c
cvs rdiff -u -r1.5 -r1.6 src/sys/arch/luna68k/dev/omrasopsvar.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.