DOS ain't dead

himemx v3.35 (Announce)

posted by Rugxulo , Usono, 11.04.2020, 02:12

Eric Auer writes again:

> Another oddity is that you use a conditional jump $+2
> after writing CR0, instead of Rod's jmp short $+2: I
> guess that has some sort of compatibility background?
>
> Actually those flags can have undefined changes by writing CR0,
> so making the post-set jump conditional would not work because
> you could not reliably send condition flags across the CR0 change.
> Another thought is that the very fact that undefined changes
> can happen could be the reason to use conditional jumps:
> A CPU jump prediction could not predict it?

Complete thread:

• himemx v3.35 - Japheth, 27.03.2020, 13:29 (Announce)
  • himemx v3.35 - nico7550, 28.03.2020, 11:31
    • himemx v3.35 - Japheth, 30.03.2020, 05:38
  • himemx v3.35 - Wengier, 31.03.2020, 03:18
    • himemx v3.35 - Japheth, 01.04.2020, 15:40
      • himemx v3.35 - RayeR, 02.04.2020, 14:59
  • himemx v3.35 - Doug, 31.03.2020, 19:23
  • himemx v3.35 - Rugxulo, 09.04.2020, 02:11
    • himemx v3.35 - Japheth, 09.04.2020, 09:41
      • himemx v3.35 - Rugxulo, 10.04.2020, 07:14
        • himemx v3.35 - Rugxulo, 11.04.2020, 02:12
        • himemx v3.35 - Japheth, 11.04.2020, 16:30
          • himemx v3.35 - Rugxulo, 12.04.2020, 14:02
            • himemx v3.35 - RayeR, 15.04.2020, 04:07
            • himemx v3.35 - Japheth, 15.04.2020, 10:05
              • himemx v3.35 - Rugxulo, 16.04.2020, 11:21
              • himemx v3.35 - Rugxulo, 16.04.2020, 11:40
            • himemx v3.35 - Rugxulo, 16.04.2020, 11:07