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The side channel attacks are not a result of programming in C, but the design of the hardware which doesn't upset the view of the system w.r.t. C compilers. Al

The side channel attacks are not a result of programming in C, but the design of the hardware which doesn't upset the view of the system w.r.t. C compilers. All programming languages, regardless of their type (imperative, functional) or interfacing method with the system (JIT, interpreted, compiled) are not immune from these attacks, because it's the hardware which is designed to emulate PDP-11. In other words, all programming languages target a modern PDP-11 at the end of the day. If hardware has shown all of its tricks (esp. cache management, invalidation, explicit prefetching, etc.), and lacked speculative, out of order execution, these problems will go away, but getting the highest performance would become much harder and complicated, and even impossible in some cases. Intel tried this with IA64, with a "No tricks, compiler shall optimize" approach, and it tanked to put it mildly (esp. after AMD64 came out).

AnimalMuppet 3y ago
Let's say we have two chips. Chip A requires the programmer to handle all the "magic" stuff. Chip B is like current chips; it hides that stuff. Chip B is subject to side channel attacks. Chip A likely is also unless the programmer is very careful. Which chip would have sold more? I assert that chip B would have, by a massive volume, because it didn't require the programmer to mess with all that stuff. So I don't think that it's fair to say that the chip is trying to look like a PDP-11 because of C. I think it's trying to look like a simpler chip, so that mere mortals can program it and still get most of the maximum performance.
- bayindirh 3y ago
  I think it depends on the toolchain. Itanium didn't sink because of the optimization it needs, but the because of the toolchain which can't do all the optimization. So, if a complex processor comes with a toolchain which does all the tuning by itself, I think it can sell equally well, because the burden will not be reflected on the developer, again. So, I think popularity of the language itself has a great impact on hardware design. AMD AthonXP had an "Optimized for Windows XP" badge on it. GPUs are built upon the programming model OpenGL and DirectX puts forward. Modern processors are made to please C and its descendants, because it's the most prominent programming model. Lisp even tried to change this with "Lisp Machines", and they failed, because Lisp was not mature/popular enough at that point. So we can say programming model drives hardware very much.

AnimalMuppet 3y ago

Let's say we have two chips. Chip A requires the programmer to handle all the "magic" stuff. Chip B is like current chips; it hides that stuff. Chip B is subject to side channel attacks. Chip A likely is also unless the programmer is very careful. Which chip would have sold more? I assert that chip B would have, by a massive volume, because it didn't require the programmer to mess with all that stuff. So I don't think that it's fair to say that the chip is trying to look like a PDP-11 because of C. I think it's trying to look like a simpler chip, so that mere mortals can program it and still get most of the maximum performance.

bayindirh 3y ago
I think it depends on the toolchain. Itanium didn't sink because of the optimization it needs, but the because of the toolchain which can't do all the optimization. So, if a complex processor comes with a toolchain which does all the tuning by itself, I think it can sell equally well, because the burden will not be reflected on the developer, again. So, I think popularity of the language itself has a great impact on hardware design. AMD AthonXP had an "Optimized for Windows XP" badge on it. GPUs are built upon the programming model OpenGL and DirectX puts forward. Modern processors are made to please C and its descendants, because it's the most prominent programming model. Lisp even tried to change this with "Lisp Machines", and they failed, because Lisp was not mature/popular enough at that point. So we can say programming model drives hardware very much.