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by jahboater
Tue Aug 06, 2019 6:31 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 161
Views: 6363

Re: Why moving to 64bit?

You know, even though you guys are few, you have really managed to get a stable and good Debian based OS, Exactly. That's the problem! If Raspbian was not such a great, well supported, well produced OS, then I'd abandon it and use Ubuntu 64 or whatever the latest thing is. almost as stable and smoo...
by jahboater
Tue Aug 06, 2019 6:16 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

Well, if your language does not allow you to read via an uninitialized pointer, if it does not allow the creation of null pointers, if it does not allow you to point at the wrong thing, if it does not allow you to share pointers for write operations, then there is no need for pointer checking at ru...
by jahboater
Tue Aug 06, 2019 2:24 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 161
Views: 6363

Re: Why moving to 64bit?

LTolledo wrote: ↑ Tue Aug 06, 2019 7:11 pm Will GPIO inputs be read faster with 64bit? will GPIO outputs switch faster on 64bit? No, because unless things have changed a lot, the GPIOs are 32 bit based and are in banks of 32 bits. Ok then.... I'll move to 64bit if the RPF supplied OS (and apps) goe...
by jahboater
Tue Aug 06, 2019 12:45 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 161
Views: 6363

Re: Why moving to 64bit?

Vanishingly few, for good and obvious reasons. But that's rather beside the point. The actual question is how many functions do I have which require local scalar variables to be preserved between function calls, and that's a: a *very* different question, and b: a much, much greater set. Perhaps tak...
by jahboater
Tue Aug 06, 2019 12:19 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 161
Views: 6363

Re: Why moving to 64bit?

dickon wrote:
Tue Aug 06, 2019 12:12 pm
But each stacked register takes twice the space...
How many functions do you have in your code with more than 30 or so local scalar variables?
60+ if you include floating point.
by jahboater
Tue Aug 06, 2019 12:17 pm
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 161
Views: 6363

Re: Why moving to 64bit?

If it makes no difference for the particular application, why does it matter? It does work, and my experiments showed quite small performance decrease not being scheduled for the new CPU. It just seems incongruous to me! How wide will the gap get - a Pi6 with an A77 CPU running ARMv6 code? I don't ...
by jahboater
Tue Aug 06, 2019 11:44 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

That was the moment I understood that C was not a high level language. Rather it is a means of writing assembler without the architecture specific instructions. After that all went well, I had written lots of assembler before that so I could deal with it. Are you saying that the definition of a hig...
by jahboater
Tue Aug 06, 2019 11:37 am
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 161
Views: 6363

Re: Why moving to 64bit?

Am I the only one who thinks the trend towards 64 bit is a bit unnecessary? No. There are gains which come from having 64-bit registers, 64-bit internal buses, 64-bit processing, and a 64-bit external bus. also 31 general purpose registers and 32 floating point registers. That means much less requi...
by jahboater
Tue Aug 06, 2019 11:22 am
Forum: General discussion
Topic: Why moving to 64bit?
Replies: 161
Views: 6363

Re: Why moving to 64bit?

You really need to search previous posts as this subject has been extensively regurgitated in various diatribes..... Yes, but things have moved on. The hardware has progressed and the software has not. The gap is widening. With the Pi3 we had the user space code compiled for ARMv6 and VFP, even tho...
by jahboater
Mon Aug 05, 2019 9:23 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

End result is that the binaries are exactly the same size! At the end of the day its only 182 bytes and it may take far more than that to affect the binary size. The "size" command may show the difference. It should be in the "text" part if its immutable like it would be in C. Anyway, who cares abo...
by jahboater
Mon Aug 05, 2019 7:55 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

[This seems to go against the -Wall language-safety features present in many C and C++ compilers that presume most developers won't run lint unless it is conveniently built into the compiler. Originally, the compiler was intended to "compile" only and produce basic "syntax error" type messages, wit...
by jahboater
Mon Aug 05, 2019 5:03 pm
Forum: General discussion
Topic: Verbose Logoff - How?
Replies: 3
Views: 107

Re: Verbose Logoff - How?

Pantard wrote:
Mon Aug 05, 2019 4:49 pm
When I shut that down I get the full verbose screen showing the system shutting down various services. I wanted to have my Raspberry Pi shutdown like that as well.
If you were on the console, you would see all that.
by jahboater
Mon Aug 05, 2019 4:22 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

Interesting! I assume you like it because it has "let" everywhere :) Trivial point, does Rust promote integers like C does? For example:- // One prime number for each lower case letter of the alphabet static PRIMES: [u64; 26] = [ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67...
by jahboater
Mon Aug 05, 2019 5:58 am
Forum: General discussion
Topic: Pi4 Cooling
Replies: 118
Views: 8381

Re: Pi4 Cooling

Randomp wrote:
Mon Aug 05, 2019 5:56 am
Heat isn't only bad because of throttling. Extended periods of heat can eventually lead to premature failure of chips. So even if it's below the throttling threshold, it can still be detrimental in the long term.
30 years instead of 35 years ?
by jahboater
Mon Aug 05, 2019 5:42 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

That aluminium case for the Pi 4B certainly looks nice. Given my budget, I suspect a different solution will present itself that involves scavenging heatsinks from surplus motherboards. More details as things develop. The wicked case is expensive and that level of cooling is not needed. Its kind of...
by jahboater
Sun Aug 04, 2019 7:10 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

should provide time to figure out a reasonable cooling solution and make a new bar chart of fame. I fancy one of these: https://wickedaluminum.com/collections/frontpage/products/raspberry-pi-4-standard-case-with-heat-dissipation They were great for the old Pi1 which needed cooling even less than th...
by jahboater
Sun Aug 04, 2019 6:32 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

Heater wrote:
Sun Aug 04, 2019 6:17 am
Looks like I have to sign up to some Rust forum to find out where to report this bug.
Or perhaps the LLVM forum?
by jahboater
Sat Aug 03, 2019 5:40 pm
Forum: C/C++
Topic: compile Linux C programs to use cpu cores exclusively
Replies: 26
Views: 987

Re: compile Linux C programs to use cpu cores exclusively

So "0x01 is the hexadecimal representation of the bits 00000001. Notice that the bit zero is set to 1, being the first bit that means run on core 0. If you want to run on core 2 use: $ taskset 0x02 myProgram Where "0x02" is 00000010 in binary, the second bit is set, so core 2. If the cores start at...
by jahboater
Sat Aug 03, 2019 5:35 pm
Forum: General discussion
Topic: Raspberry Pi 4 RAM variants
Replies: 17
Views: 1006

Re: Raspberry Pi 4 RAM variants

But there are 35 address bits for the future ...
by jahboater
Sat Aug 03, 2019 5:31 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

Edit: When I replace all those short circuit operatirs, "++", "|=", etc, with their long hand equivalents in fftbench it runs at exactly the same speed. Not surprising I guess. So which version did you think was the most readable? I have been looking at C for so many decades that I find the += form...
by jahboater
Sat Aug 03, 2019 5:17 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

Edit: When I replace all those short circuit operatirs, "++", "|=", etc, with their long hand equivalents in fftbench it runs at exactly the same speed. Not surprising I guess. So which version did you think was the most readable? I have been looking at C for so many decades that I find the += form...
by jahboater
Sat Aug 03, 2019 4:53 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

What better way to do that than have the compiler do it? Interesting idea. But I am sorry, I still don't like it. Imagine if Denis Ritchie had dictated the coding standards for all C programmers for all time - 48 years ago. (I doubt if C would have been so successful, people would rebel against the...
by jahboater
Sat Aug 03, 2019 1:18 pm
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

From purely selfish motive I would be happy if every one who ever published code that I end up reading was forced to use the same style and bared from using confusing constructs. It's not just me, work on any large project and they will likely have a style guides and coding rules that get checked a...
by jahboater
Sat Aug 03, 2019 9:12 am
Forum: General programming discussion
Topic: Project Digital Apocalypse Not Now
Replies: 1061
Views: 39053

Re: Project Digital Apocalypse Not Now

0. Operator precedence is same as C. - Saves confusing users of C/C++ etc. Really? even with & and | lower than == which has always been considered a mistake? (although chosen with good reason at the time). 2. Curly braces required around conditional blocks, even if they are only one line. - Consis...
by jahboater
Sat Aug 03, 2019 8:57 am
Forum: General discussion
Topic: So What OS Works With Pi4 4gb?
Replies: 19
Views: 1039

Re: So What OS Works With Pi4 4gb?

If you have access to a SD card to USB adapter you would be able to write OS images from the RPI4 running Raspbian without needing to use the etcher program on a different computer, you write the OS image using the "dd" command. Its only a simple copy, so the ordinary "cp" command is simpler to use...

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