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by jahboater
Sun Aug 04, 2019 6:32 am
Forum: General programming discussion
Topic: Liberation through Computer Literacy
Replies: 1093
Views: 41188

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: 1474

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: 1036

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: Liberation through Computer Literacy
Replies: 1093
Views: 41188

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: Liberation through Computer Literacy
Replies: 1093
Views: 41188

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: Liberation through Computer Literacy
Replies: 1093
Views: 41188

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: Liberation through Computer Literacy
Replies: 1093
Views: 41188

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: Liberation through Computer Literacy
Replies: 1093
Views: 41188

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: 1074

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...
by jahboater
Fri Aug 02, 2019 2:52 pm
Forum: Beginners
Topic: Coding languages on the Pi?
Replies: 26
Views: 709

Re: Coding languages on the Pi?

Boring advice: pick a well-known and well supported language such as Python3 or C or C++. Study it in depth and write and modify code using it for some time until you are fluent in using it to express your requirements and to debug the problems you will encounter. About 3 years will be needed for t...
by jahboater
Fri Aug 02, 2019 10:27 am
Forum: Beginners
Topic: Coding languages on the Pi?
Replies: 26
Views: 709

Re: Coding languages on the Pi?

I have been looking at C, and it's still a pretty relative. I'm sure it has it's cons too, so the opinions of both proponents and opponents of a coding language are appreciated! More than half the worlds software is written in C - with good reason. Look at the TIOBE history (which may or may not be...
by jahboater
Fri Aug 02, 2019 10:23 am
Forum: General discussion
Topic: 4gb - 4B Demand must be high.
Replies: 134
Views: 6109

Re: 4gb - 4B Demand must be high.

Nuncio wrote:
Fri Aug 02, 2019 10:18 am
I ordered mine Sat July 27 and just got it yesterday 1 Aug
From CanaKit
I ordered mine within a minute or so after I saw the announcement.
Glad I did - I got a 4GB model the next day.
Now I cant get a second one of course.
by jahboater
Fri Aug 02, 2019 9:51 am
Forum: Beginners
Topic: Coding languages on the Pi?
Replies: 26
Views: 709

Re: Coding languages on the Pi?

TASM, because a great program from my youth was made in it and the source codes are available for grabs. I just wanted to look in them. You can look at assembler source code with any text editor. I like easy languages, but I also like efficient coding, where the programs use very little system reso...
by jahboater
Fri Aug 02, 2019 9:45 am
Forum: General discussion
Topic: /var/run tmpfs
Replies: 5
Views: 2757

Re: /var/run tmpfs

Distributor ID: Raspbian Description: Raspbian GNU/Linux 9.3 (stretch) Release: 9.3 Codename: stretch So are these the defaults paths for tmpfs on debian ? What happens if some paths are also takes place in fstab ? For example i have set an similar Line in fstab for the /tmp path Best regards mjoe ...
by jahboater
Fri Aug 02, 2019 9:30 am
Forum: Beginners
Topic: Why does the raspberry-pi-zero return “Illegal instruction” after I wrote a command that is working on raspberry-pi 3 B+
Replies: 9
Views: 254

Re: Why does the raspberry-pi-zero return “Illegal instruction” after I wrote a command that is working on raspberry-pi

You could try

-mcpu=arm1176jzf-s -mtune=arm1176jzf-s -mfpu=vfp

for the Pi Zero.
If it doesn't work, as JamesH says, build it on the Zero. A bit slower, but will work fine.
by jahboater
Fri Aug 02, 2019 9:10 am
Forum: General discussion
Topic: So What OS Works With Pi4 4gb?
Replies: 19
Views: 1074

Re: So What OS Works With Pi4 4gb?

jamesh wrote:
Fri Aug 02, 2019 8:51 am
On the whole, formatting first is either a) a waste of time or b) reduces the lifetime of the card.
Or both.
by jahboater
Fri Aug 02, 2019 9:01 am
Forum: General discussion
Topic: 4gb - 4B Demand must be high.
Replies: 134
Views: 6109

Re: 4gb - 4B Demand must be high.

The Odroid-N2 came with a choice of 2GB or 4GB and I believe the 4GB was far more popular. So, why DO people want the 4GB, when the 2GB would do the job? Human nature :) Why do people drive 300BHP cars when a 100BHP car gets you from a to b easily? Seriously ... In case it doesn't do the job for som...
by jahboater
Fri Aug 02, 2019 7:49 am
Forum: Beginners
Topic: Coding languages on the Pi?
Replies: 26
Views: 709

Re: Coding languages on the Pi?

"Shell" is pre-installed as well of course. People usually use bash.

An assembler is also included. It is called "as". Why would you want to use TASM on the Pi?
by jahboater
Thu Aug 01, 2019 7:46 pm
Forum: Off topic discussion
Topic: Before Raspberry Pi
Replies: 14
Views: 1705

Re: Before Raspberry Pi

Heater wrote:
Wed Jul 31, 2019 3:17 am
It's even better. That 4Mz 8080 was probably running at 1 MIPs or so. The Pi 4 is more like 1 GIP.

And it has 4 cores. 4000 times faster!
Even faster still, its triple issue super scalar.
by jahboater
Wed Jul 31, 2019 3:19 pm
Forum: C/C++
Topic: more performance optimizations for pi4 compiles?
Replies: 3
Views: 712

Re: more performance optimizations for pi4 compiles?

Those are specific for OPENCV.
by jahboater
Wed Jul 31, 2019 1:26 pm
Forum: C/C++
Topic: more performance optimizations for pi4 compiles?
Replies: 3
Views: 712

Re: more performance optimizations for pi4 compiles?

On pi3 we can use -D ENABLE_NEON=ON \ -D ENABLE_VFPV3=ON \ I'm just wondering if we can do more to help performance on a pi 4? Where are those documented ? I give these options to the compiler: -mcpu=cortex-a72 -mtune=cortex-a72 -mfpu=neon-fp-armv8 additionally, this option may help if you are doin...
by jahboater
Tue Jul 30, 2019 2:48 pm
Forum: General discussion
Topic: Raspberry pi for coding on machine level?
Replies: 31
Views: 1237

Re: Raspberry pi for coding on machine level?

If the objective is simply exposure to assembly level programming, my suggestion would be to start on something with a dirt simple machine architecture, like a PIC microcontroller. The level of support available will probably be better than on more complex architectures because it's a practical app...
by jahboater
Tue Jul 30, 2019 1:24 pm
Forum: C/C++
Topic: StdLib Dirty Replacement Functions:
Replies: 20
Views: 754

Re: StdLib Dirty Replacement Functions:

..along with the other options. The latter is definitely not recommended for a "production" compiler but it will save a ton of time. The full build with the bootstrap took 3 hours 15 minutes on my 4GB Pi4 (no throttling). That was for --enable-languages=c,c++ make -j5 and no need to worry about swa...
by jahboater
Tue Jul 30, 2019 10:46 am
Forum: General discussion
Topic: Learning Assembler on the Pi
Replies: 51
Views: 1526

Re: Learning Assembler on the Pi

Firstly, I'd like to say that: possibly, maybe, I was overstating the case in my claims there for safety checks without performance loss. It may well not be possible all the time in all cases. Yes. When the compiler knows the index value and the size of the array, then the cost will be nil, as its ...
by jahboater
Tue Jul 30, 2019 7:21 am
Forum: General discussion
Topic: Learning Assembler on the Pi
Replies: 51
Views: 1526

Re: Learning Assembler on the Pi

1) It is possible, contrary to many claims, to add array bounds and integer overflow detection without impacting performance. See the current anagram challenge solutions on C++ and Rust. You mean the run-time checks of array bounds and integer overflow, didn't produce a measurable drop in performan...

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