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0 pointspjmlp2y ago0 comments

Yes, younger devs grown up on the myth of C and C++ being always fast, have missed the days when inline Assembly was a higher count than pure C and C++ code.

I have seen applications for MS-DOS, effectively using C as a Macro Assembler, only the data structures and high level logic was C as if Macro Assembler macros.

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6 comments · 2 top-level

loup-vaillant2y ago· 3 in thread

> Yes, younger devs grown up on the myth of C and C++ being always fast, have missed the days when inline Assembly was a higher count than pure C and C++ code.

And still is in VLC. (Okay, maybe not higher, but they do use a crapton of assembly in their decoders, and it does speed them up by a factor of 10 or so today.)

pjmlpOP2y ago

Video decoding has always been a prime example for SIMD stuff, however I wonder how much of that code VLC devs could wipeout, assuming hardware vídeo decoding being available everywhere.

hnthrowaway03282y ago

Do you mean the VLC media player? Just curious is there any reason modern compilers don't beat assemblies or is that simply a legacy issue?

pjmlpOP2y ago

Compilers beat hand written Assembly for the general use cases.

Now beating special use cases, like using vector instructions to parallel process video decoding streams is another matter.

It is no accident that after all the efforts improving Java and .NET JITs for auto-vectorization across various vendors, both platforms now expose SIMD intrinsics as well.

Keyframe2y ago· 1 in thread

I was there, 3000 years ago, when C was considered bloated and slow. Times are a changing.

pjmlpOP2y ago

Unfortunately much of those optimizations are thanks to taking UB to full throttle.

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