DOS ain't dead - SSE instructions in DOS programs?

SSE instructions in DOS programs? (Developers)

posted by RayeR , CZ, 02.01.2019, 22:56

> Internet says that it is enough to test the 9.bit and 10.bit in the CR4
> register. But "MOV CR4,AX" is a privileged instruction. So - what to do?

Is it necessary under pure DOS? If there will run only one program that use SSE it shouldn't be needed to save context as nothing else could corrupt it. It would probably work for Win95 too - task will be switched but SSE regs remains if no other app wil use it. But of course it would be correct to use context saving. BTW you will need extra alignment for SSE data (and maybe instructions?) I think 16B boundary. There was a problem that SSE code of FFMPEG didn't work under DOS/DJGPP so I disabled all inline asm code for SSE but I never went deep into it if there's some workaround.

---
DOS gives me freedom to unlimited HW access.

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Complete thread:

SSE instructions in DOS programs? - Laaca, 02.01.2019, 00:07
- SSE instructions in DOS programs? - alexfru, 02.01.2019, 00:31
- SSE instructions in DOS programs? - Rugxulo, 02.01.2019, 10:08
- SSE instructions in DOS programs? - RayeR, 02.01.2019, 22:56
  - SSE instructions in DOS programs? - Laaca, 03.01.2019, 12:51
    - SSE instructions in DOS programs? - Laaca, 03.01.2019, 12:52
    - SSE instructions in DOS programs? - RayeR, 03.01.2019, 14:32
      - SSE instructions in DOS programs? - RayeR, 03.01.2019, 14:39
  - SSE instructions in DOS programs? - marcov, 04.01.2019, 23:37
    - SSE instructions in DOS programs? - Rugxulo, 12.01.2019, 23:54
      - SSE instructions in DOS programs? - RayeR, 13.01.2019, 16:44