Re: Stealing a Great Idea from the 6600

On 4/28/2024 12:56 AM, BGB wrote:

On 4/27/2024 8:45 PM, MitchAlsup1 wrote:

BGB wrote:
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I guess some people are dragging their feet on FDPIC, as there is some debate as to whether or not NOMMU makes sense for RISC-V, along with its associated performance impact if used.

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In my case, if I wanted to go over to simple base-relocatable images, this would technically eliminate the need for GBR reloading.

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Checks:
Simple base-relocatable case actually currently generates bigger binaries, I suspect because in this case it is less space-efficient to use PC-rel vs GBR-rel.

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Went and added a "pbostatic" option, which sidesteps saving and restoring GBR (making the simplifying assumption that functions will never be called from outside the current binary).

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This saves roughly 4K (Doom's ".text" shrinks to 280K).

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Would you be willing to compile DOOM with Brian's LLVM compiler and
show the results ??
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Will need to download and build this compiler...

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Might need to look into this.

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Please do.
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 Extracting the ZIP file and "git clone llvm-project" etc, have thus far taken hours...
 Well, and then the commands to CMake were not working, tried invoking cmake more minimally, and it gives a message complaining about the version being too old, ...
 Seems I have to build it with a different / newer WSL instance (well, I guess it was either this or try to rebuild CMake from source).
  Checks, download for compiler (+ git cloned LLVM) is a little over 6GB.
  Well, OK, now LLVM is building... I guess, will see if it compiles and doesn't explode in the process. Probably going to be a while it seems.
 

A little over an hour later and it still hasn't broken 50% yet...
I think LLVM rebuilds may have actually gotten slower than in the past...
Well, at least my 112GB of RAM means it isn't swapping too much...
Computer is a little sluggish and the "System" process seems kinda pegged out though...
I guess I will know sometime later whether or not all of this builds...