compiler-explorer VS rizin

At least on android arm64, looks like a `dmb ishst` is emitted after the constructor, which allows future loads to not need an explicit barrier. Removing `final` from the field causes that barrier to not be emitted.

https://godbolt.org/#g:!((g:!((g:!((h:codeEditor,i:(filename...

You said You won't get "extreme performance" from C++ because it is buried under the weight of decades of compatibility hacks.

Now your whole comment is about vector behavior. You haven't talked about what 'decades of compatibility hacks' are holding back performance. Whatever behavior you want from a vector is not a language limitation.

You could write your own vector and be done with it, although I'm still not sure what you mean, since once you reserve capacity a vector still doubles capacity when you overrun it. The reason this is never a performance obstacle is that if you're going to use more memory anyway, you reserve more up front. This is what any normal programmer does and they move on.

Show what you mean here:

https://godbolt.org/

I've never used ISPC. It's somewhat interesting although since it's Intel focused of course it's not actually portable.

I guess now the goal posts are shifting. First it was that "C++ as a language has performance limitations" now it's "rust has a vector that has a function I want and also I want SIMD stuff that doesn't exist. It does exist? not like that!"

Try to stay on track. You said there were "decades of compatibility hacks" holding back C++ performance then you went down a rabbit hole that has nothing to do with supporting that.

C++ Insights is available online at https://cppinsights.io/

It is also available at a touch of a button within the most excellent https://godbolt.org/

along side the button that takes your code sample to https://quick-bench.com/

Those sites and https://cppreference.com/ are what I'm using constantly while coding.

I recently discovered https://whitebox.systems/ It's a local app with a $69 one-time charge. And, it only really works with "C With Classes" style functions. But, it looks promising as another productivity boost.

[P&H RISC] https://www.google.com/books/edition/_/e8DvDwAAQBAJ

Compiler Explorer by Matt Godbolt [Godbolt] can help better understand what code a compiler generates under different circumstances.

[Godbolt] https://godbolt.org

The official CPU architecture manuals from CPU vendors are surprisingly readable and information-rich. I only read the fragments that I need or that I am interested in and move on. Here is the Intel’s one [Intel]. I use the Combined Volume Set, which is a huge PDF comprising all the ten volumes. It is easier to search in when it’s all in one file. I can open several copies on different pages to make navigation easier.

Intel also has a whole optimization reference manual [Intel] (scroll down, it’s all on the same page). The manual helps understand what exactly the CPU is doing.

[Intel] https://www.intel.com/content/www/us/en/developer/articles/t...

Personally, I believe in automated benchmarks that measure end-to-end what is actually important and notify you when a change impacts performance for the worse.

Let's compile it with https://godbolt.org/, turn on some optimisations and inspect the IR (-O2 -emit-llvm). Copying out the part that corresponds to the while loop:

  4:

resources were extra useful when building deeper intuitions about GPU performance for ML models at work and in graduate school.

- CMU's "Deep Learning Systems" Course is hosted online and has YouTube lectures online. While not generally relevant to software performance, it is especially useful for engineers interested in building strong fundamentals that will serve them well when taking ML models into production environments: https://dlsyscourse.org/

- Compiler Explorer is a tool that allows you easily input some code in and check how the assembly output maps to the source. I think this is exceptionally useful for beginner/intermediate programmers who are familiar with one compiled high-level language and have not been exposed to reading lots of assembly. It is also great for testing how different compiler flags affect assembly output. Many people used to coding in C and C++ probably know about this, but I still run into people who haven't so I share it whenever performance comes up: https://godbolt.org/

To really understand what's going on here we can look at the compiled assembly code. I'm working on a Mac and can do this using the objdump tool. Compiler Explorer is also a handy tool but doesn't seem to support Arm assembly which is what Rust will use when compiling on Apple Silicon.

Play around with it in godbolt if you're really curious: https://godbolt.org/

Just for the record, for nicer inspection of files with such debug information, including compressed sections, and debuginfod support, Rizin[1] can be used, since starting from the 0.7.0 release[2] all of those were added.

[1] https://rizin.re

[2] https://github.com/rizinorg/rizin/releases/tag/v0.7.0

Rizin[1] is also able to uplift native code to the new RzIL, which is based on the BAP Core Theory[2] and is essentially an extension of SMT theories of bitvectors, bitvector-indexed arrays of bitvectors and effects[3].

[1] https://rizin.re/

[2] https://binaryanalysisplatform.github.io/bap/api/master/bap-...

[3] https://github.com/rizinorg/rizin/blob/dev/doc/rzil.md

Everything Hiew can do, Rizin[1] can do too, and is completely free and open source[2] under LGPL3 license. Moreover, it supports more architectures, platforms, and file formats, as well as GUI in Qt - Cutter[3][4]. If something is missing in Rizin but presented in Hiew, please let us know by opening the issue with details.

[1] https://rizin.re

[2] https://github.com/rizinorg/rizin

[3] https://cutter.re

[4] https://github.com/rizinorg/cutter

This is precisely what we are trying to do at Rizin[1][2]. Though the primary goal of the tool/framework is static analysis. All that portability across OSes, their versions, platforms and architectures, etc is definitely hard. If anyone is interested in these subjects, all contributions are welcome. For example, check out our "RzDebug" label, marking debugging issues[3].

[1] https://rizin.re

[2] https://github.com/rizinorg/rizin

[3] https://github.com/rizinorg/rizin/labels/RzDebug

Okay, so, your comment about a "Dasher + Guitar Hero music theory/improvisation practice program" just sent me down a huge rabbit hole...

Well, rabbit hole(s) plural, I guess, most not directly related. :D

Largely because I made the "mistake" of looking at your HN profile & discovering you're also in NZ & we seem to have somewhat overlapping interests (and an affinity for "bacon" in account names, apparently), so, some thoughts[0]... :)

# Topic 1: Nissan Leaf VSP hacking

After reading your recent posts (https://ianrrees.github.io//2023/07/03/vsp-hacking.html & https://ianrrees.github.io//2023/08/05/voltage-glitch-inject...) on this topic & noting your remark about wanting to try reverse engineering a firmware image, I found the following thesis PDF (via a brief google search for `"reverse engineer" "firmware" "Renesas"`):

* "AUTOMOTIVE FIRMWARE EXTRACTION AND ANALYSIS TECHNIQUES" by Jan Van den Herrewegen https://etheses.bham.ac.uk/id/eprint/11516/1/VandenHerrewege...

Not really what I was anticipating finding but seems relevant to your interests--I don't think it was already in your resource list.

While the thesis addresses the Renesas 78K0 rather than the Renesas 78K0R, from a brief look at the "Flash Protection" PDF Application Note in your resource list it seems there's a large overlap.

Perhaps most significantly the author presents "novel methods" that combine bootloader binary analysis with constraint-based power glitching in an effort to improve on the results described in "Shaping the Glitch".

While I haven't read the entire 186 pages :D they theorize that using their approach extracting 8kB firmware might only take ~10 hours.

And, most helpfully, they even published their source code under the GPL here: https://github.com/janvdherrewegen/bootl-attacks

So, an interesting adjacent read even if it turns out not to be directly applicable to your situation.

Given I have an interest in & a little experience with firmware reversing my original thought was to maybe provide some hopefully helpful references that more generically related to firmware reversing but more specific is good too, I guess. :)

In terms of reverse engineering tooling, I've used Rizin/Cutter/radare2 previously: https://rizin.re https://cutter.re

On the CAN tooling/info front, you might be interested in taking a look at my "Adequate CAN" list which I originally wrote-up for a client a couple years ago: https://gitlab.com/RancidBacon/adequate-can

Some other probably outdated reverse engineering tooling links of mine: https://web.archive.org/web/20200119074540/http://www.labrad...

In terms of how to approach RE, other than just "getting started & digging in" & learning by doing, I've sometimes found it informative to read other people's firmware reverse engineering write-ups to learn about potentially useful approaches/tools.

Anyway, hopefully some of this is helpful!

[0] I have a tendency to be a little... "verbose" and/or "thorough" (depending on one's POV :) ) so I'll probably split this over a couple of comments, in case I run out of steam while writing and for topic separation.

See our FAQ[1] on why we forked. As three years passed and both projects are actively developed, the divergence has grown a lot since. We aim for exposing the proper API instead of relying just commands, see e.g. our new Python bindings and rz-bindgen[2]. We have completely different concept of projects, new intermediate language - RzIL[3], and many other things. And under the new organization Cutter is a first-class citizen, not an afterthought as before.

[1] https://rizin.re/posts/faq/

[2] https://rizin.re/posts/gsoc-2022-rz-bindgen/

[3] https://github.com/rizinorg/rizin/blob/dev/doc/rzil.md