ARM builds and SIMD-assembler prospects

[ewmayer]

OK, gonna try to set up my Odroid in the next couple of days ... first issue is that I think I may need a proper display adapter. I use a 15-pin (standard display pinout) to mini-Display-port adapter on my Intel NUC, but don't see a mini-Display port on the Odroid.

The other adapter I have on hand is 15-pin to what looks like 2 parallel, thin, roughly microSD-width slivers, each with what looks like 8 tiny pin contacts (hard to make out even under magnifying glass), the two 8-pin dealies seprated by ~1-1.5 mm. Again don't see anything like that on the Odroid.

Should I just order a 15-pin to HDMI adapter cable?

[ET_]

Originally Posted by ewmayer

OK, gonna try to set up my Odroid in the next couple of days ... first issue is that I think I may need a proper display adapter. I use a 15-pin (standard display pinout) to mini-Display-port adapter on my Intel NUC, but don't see a mini-Display port on the Odroid.

The other adapter I have on hand is 15-pin to what looks like 2 parallel, thin, roughly microSD-width slivers, each with what looks like 8 tiny pin contacts (hard to make out even under magnifying glass), the two 8-pin dealies seprated by ~1-1.5 mm. Again don't see anything like that on the Odroid.

Should I just order a 15-pin to HDMI adapter cable?

My monitor has 2 HDMI inputs (and 1 15-pin VGA), so I ordered the HDMI cable and plugged it to the monitor as a secondary input.

[ewmayer]

Originally Posted by ET_

My monitor has 2 HDMI inputs (and 1 15-pin VGA), so I ordered the HDMI cable and plugged it to the monitor as a secondary input.

I'll probably get a VGA-to-HDMI adapter - that way I can use the existing VGA cable dangling down from the display and simply switch it between the NUC's mini-display adapter dongle and the adapter for the Odroid as needed. (The NUC only very rarely needs to be hooked to the display anymore, pretty much only when I need to restart after a power outage.)

But, do I need a male or female HDMI plug on the adapter? Not having mucked about with HDMI and having only one end of the equation to eyeball - the Odroid C2 HDMI plug - it's not clear to me whether the latter is male or female. (I.e. I've never "sexed an HDMI" before, and have only one exemplar of the species to inspect. :)

[henryzz]

Originally Posted by ewmayer

I'll probably get a VGA-to-HDMI adapter - that way I can use the existing VGA cable dangling down from the display and simply switch it between the NUC's mini-display adapter dongle and the adapter for the Odroid as needed. (The NUC only very rarely needs to be hooked to the display anymore, pretty much only when I need to restart after a power outage.)

But, do I need a male or female HDMI plug on the adapter? Not having mucked about with HDMI and having only one end of the equation to eyeball - the Odroid C2 HDMI plug - it's not clear to me whether the latter is male or female. (I.e. I've never "sexed an HDMI" before, and have only one exemplar of the species to inspect. :)

Generally a socket is female and the side with prongs is male(guess where that came from).
The Odroid will have a female socket. I expect you will use a male to male hdmi cable to connect to the adapter. You will also want a male to male vga cable from the adapter to your screen.
The adapter will need to have both sockets female. You will need to make sure that it is a hdmi to vga adaptor rather than a vga to hdmi adaptor.


As a general rule most cables with the same end on both sides are male.

[ldesnogu]

Originally Posted by ewmayer

I'll probably get a VGA-to-HDMI adapter - that way I can use the existing VGA cable dangling down from the display and simply switch it between the NUC's mini-display adapter dongle and the adapter for the Odroid as needed.

Isn't it an HDMI-to-VGA adapter that you need since your device is outputting through HDMI?

I'm on a coffee diet so sorry if I completely misunderstood, my brain is compromised by lack of caffeine

[ewmayer]

Originally Posted by henryzz

The Odroid will have a female socket. I expect you will use a male to male hdmi cable to connect to the adapter. You will also want a male to male vga cable from the adapter to your screen.

Yeah, looking at my NUC VGA-to-mini-display adapter dongle, VGA side is F (to take the M VGA plug from the monitor VGA-to-VGA cable), device side mini-connector is M. So I figured that F-to-M dongle scheme was standard and went ahead and ordered this $8 special.

Laurent, does that answer your fog-of-decaffeination question?

[ldesnogu]

Definitely

[ewmayer]

Originally Posted by ldesnogu

Definitely

[ewmayer]

VGA-to-HDMI adapter dongle arrived today, a day late - slipped MicroSD with preloaded boot image (bought from Hardkernel as an accessory - I have a USB-flash-format MicroSD reader, so now will stick MicroSD in that, turning it into an 8GB thumb drive, 4x larger than any dedicated such I had on hand previosuly) into slot on underside of board, hooked up to monitor, plugged in 5V DC power mini-plug, within a minute was looking at a Ubuntu login prompt. Default user-login was with ID 'odroid' and password the same ... once in I tried to su root but 'root' is not the default pwd for that - do any Odroiders know what it is?

@Luigi: the 'gcc -dM -E - < /dev/null' trick worked fine for me in terms of dumping the predefines (copied to attached bzip2'ed arm.predefs text file) - you sure you typed it properly?

Trial build of a small source file quickly turned up a bug in the imul_macro0.h file, key 64-bit integer-mul macros were getting left undefined ... I traced that to preprocessor/macro stuff I added in the last few years to implement such macros in Nvidia CUDA PTX code. Fixed-up version of that file also attached - ARM Neon probably has decent 64-bit-int hardware-MUL support, but I've yet to dig deeply into the instruction set, and not crucial for the LL-testing stuff, in any event.

With those patches, multithreaded scalar-double (i.e. generic-C) build succeeded, self-tests running now, albeit quite slow, between the generic-C-ness and just 1-threaded for first set of such self-tests. E.g. 230 ms/iter @1024K, 25-30x slower than a single AMD Ryzen core running AVX2 code. But if I can get a 2.5-3x speedup from vector-128-bit-SIMD assembler on the Neon, 1/10th the per-core performance of Ryzen at only $10/core (sans any volume discounts) would be not too bad.

Will post self-test timings @1,2,4-threads tomorrow.

[paulunderwood]

Originally Posted by ewmayer

...Ubuntu login prompt. Default user-login was with ID 'odroid' and password the same ... once in I tried to su root but 'root' is not the default pwd for that - do any Odroiders know what it is?

Prefix each root command with sudo and enter your user password.

My guess is you can do sudo passwd root if you want to set up a root password.

Or run sudo su to run root commands.

[ET_]

Originally Posted by ewmayer

@Luigi: the 'gcc -dM -E - < /dev/null' trick worked fine for me in terms of dumping the predefines (copied to attached bzip2'ed arm.predefs text file) - you sure you typed it properly?

I'm afraid I forgot the '-' after the E

The code compiles and runs happily
I am running the selftest with 1 thread (./Mlucas -s m > selftest.log) and will share the log as I have it (I'm at 1408K right now). Let me know if you still need my prefs.arm file as well.

The [M|m]lucas.cfg file is not written. The code detects its lack, but when it tries to write (r+) it does not succeed.

To do a selftest with more threads, should I try

./Mlucas -s m -nthread [2|4]

or

./Mlucas -s m -cpu 0:3

?