Quote:
Originally Posted by manolito
So the difference is only for plain C code which gets either converted to SIMD instructions (if the CPU supports it) or not.
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No. Think of it like a plain vanilla/yellow cake. You want chocolate with the cake. The SIMD instructions that come from the dedicated intrinsics functions are like chocolate frosting - it's on top, makes it taste better, but if you got a slice and didn't want any of the frosting, you could scrape it off. This is the option that's 'it gets used if the CPU supports it'.
/arch and optimizing even the C parts with SIMD is making the cake itself a marble, or straight-up chocolate, cake - if you want to avoid the chocolate, you can't. It's in there, whether you like it or not. Whether the CPU supports it or not (and if the CPU doesn't support it, it crashes with an Illegal instruction error).
I did absolutely nothing to branch AviSynth+'s CPU support. The only difference between the typical builds pinterf has been providing and the one I posted a little bit ago is that I switched /arch back to SSE before building it, the way it was on the original AviSynth+ repo before ultim went on hiatus again (as you can see, it was last updated in August 2016, which is why pinterf's repo is the current development hub everyone points to now):
https://github.com/AviSynth/AviSynth...eLists.txt#L48
vs.
https://github.com/pinterf/AviSynthP...eLists.txt#L74
All I did in my working branch (
https://github.com/qyot27/AviSynthPl...eLists.txt#L74) was make it so that when I go to build AviSynth+, I don't have to open CMakeLists.txt in Notepad2-mod and change it back to SSE. Instead, I can now pass -DCPU_ARCH=SSE (or -DCPU_ARCH=IA32, -DCPU_ARCH=AVX, or -DCPU_ARCH=AVX2) to the CMake command line, like any other configuration option and avoid having to open source files in text editors first.
As for why it hasn't shown up outside of my branch, A) I just whipped up that patch earlier this week or last week, and B) I've not opened a pull request for the changes on that branch yet.