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Earlier quoted context omitted.
So there are more bugs in a more readable and understandable programming language (C) as opposed to asm? What gives? I am asking because intuition would say the opposite since asm is much more lower-level than C.
compiler optimization is a blackbox. shortcuts to crypto routines will allow side channel attacks
What is the "nasty surprise" of Zen 4 AVX512? Sure, it's not quite the twice as fast you might initially assume, but (unlike Intel's downclocking) it's still a strict upgrade over AVX2, is it not?
> it's still a strict upgrade over AVX2 If you benchmark it, it will be slower about half the time.
What is the "nasty surprise" of Zen 4 AVX512? Sure, it's not quite the twice as fast you might initially assume, but (unlike Intel's downclocking) it's still a strict upgrade over AVX2, is it not?
It's splitting a 512 instruction into 2 256 instructions internally. That's the main nasty surpise. I suppose it saves on the decoding portion a little but it's ultimately no more effective than just issuing the 2 256 instructions yourself.
This article references the fact that security issues in crypto libs are memory safety issues, and I think this is meant to be a motivator for writing the crypto using SIMD intrinsics. This misses two key issues. 1. If you want to really trust that your crypto code has no timing side channels, then you've gotta write it in assembly. Otherwise, you're at the compiler's whims to turn code that seems like it really shou…
This article references the fact that security issues in crypto libs are memory safety issues, and I think this is meant to be a motivator for writing the crypto using SIMD intrinsics. This misses two key issues. 1. If you want to really trust that your crypto code has no timing side channels, then you've gotta write it in assembly. Otherwise, you're at the compiler's whims to turn code that seems like it really shou…
So there are more bugs in a more readable and understandable programming language (C) as opposed to asm? What gives? I am asking because intuition would say the opposite since asm is much more lower-level than C.
This article references the fact that security issues in crypto libs are memory safety issues, and I think this is meant to be a motivator for writing the crypto using SIMD intrinsics. This misses two key issues. 1. If you want to really trust that your crypto code has no timing side channels, then you've gotta write it in assembly. Otherwise, you're at the compiler's whims to turn code that seems like it really shou…
So there are more bugs in a more readable and understandable programming language (C) as opposed to asm? What gives? I am asking because intuition would say the opposite since asm is much more lower-level than C.
> For example, NEON ... can hold up to 32 128-bit vectors to perform your operations without having to touch the "slow" memory. Something I recently learnt: the actual number of physical registers in modern x86 CPUs are significantly larger, even for 512-bit SIMD. Zen 5 CPUs actually have 384 vectors registers, 384*512b = 24KB!
This is true, but if you run out of the 32 register names you’ll still need to spill to memory. The large register file is to allow for multiple instructions to execute in parallel among other things.
This article references the fact that security issues in crypto libs are memory safety issues, and I think this is meant to be a motivator for writing the crypto using SIMD intrinsics. This misses two key issues. 1. If you want to really trust that your crypto code has no timing side channels, then you've gotta write it in assembly. Otherwise, you're at the compiler's whims to turn code that seems like it really shou…
I can't review assembly, agreed on better language part but we'd need tooling to help prove it's correctness of you want the asm path.
Earlier quoted context omitted.
Didn't know about this. Thanks! Not related, but I often want to see the next or previous element when I'm iterating. When that happens, I always have to switch to an index-based loop. Is there a function that returns Iter )> where the second element is a lookahead?
You probably just want to use `.peekable()`: https://doc.rust-lang.org/stable/std/iter/trait.Iterator.htm...