Difference between pages "Coding Standards" and "Amd64-jaguar"

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== Basic Coding Standards In A Nutshell ==
{{Subarch
|CPU Family=64-Bit AMD Processors
|subarch=amd64-jaguar
|CHOST=x86_64-pc-linux-gnu
|CFLAGS=-march=btver2 -O2 -pipe
|USE=mmx sse sse2 sse3 sse4 3dnow 3dnowext
|CPU Features=low-power
|Description=
}}
The '''amd64-jaguar''' (also called AMD Family 16h) subarch supports the  [[Wikipedia:Jaguar (microarchitecture)|AMD jaguar microarchitecture]], which is targeted at low-power devices, including notebooks, tablets and small form-factor desktops and servers. It is perhaps most well-known for being the microarchitecture used for the [[Wikipedia:Playstation 4|Playstation 4]] and [[Wikipedia:Xbox One|Xbox One]], which each use custom 8-core Jaguar APUs.
Socketed Jaguar APUs use the [[Wikipedia:AM1 Socket|AM1 socket]], and  [[Wikipedia:Socket_FT3|FT3 socket]] for mobile devices. G-series [[Wikipedia:System_on_a_chip|"system on a chip" (SoC)]] APUs are available for non-socketed devices such as tablets and embedded system boards.


* word wrap at 160 characters
Desktop Jaguar APUs include the [[Wikipedia:List_of_AMD_accelerated_processing_unit_microprocessors#.22Kabini.22.2C_.22Temash.22_.282013.2C_28_nm.29|Kabini A-series APUs and Temash E-series APUs]], such as the Athlon 5150 and 5350 APUs, and Sempron 2650 and 3850.
* use tabs, not spaces, for indentation
* use a tab size of 4 characters (tab size can be adjusted but it affects when you reach the magic 160 char wrap limit)
* comments on separate lines, at same indent level as code (sections can be marked by 'outdented' comments)


== Word Wrap ==
Amd64-jaguar subarches use the MOVBE instruction which is not available on amd64-bulldozer, amd64-piledriver or amd64-steamroller. They are thus not instruction-compatible with any of these subarches.
 
Modern editors do a good job of displaying very long lines of text, and modern displays have sufficient resolution for displaying much more than 80 characters per line, even at 1024x768 resolution. You should definitely not split an elegant single-line piece of code into multiple lines just for the sake of keeping the whole thing under 80 characters. It's especially bad if you take, say, a 100-character line and split it into ''more'' than two lines just for the sake of keeping it under 80 characters in length. But you need or want to use multiple lines to keep your code readable, more power to you. Don't just do it to maintain "Apple IIe with 80-column card compatibility" for any reason. That's just silly.
 
== Tabs vs. Spaces ==
 
Tabs and spaces had a fight. Tabs won. They're easier to deal with and allow configurable indentation for those who require it. I don't care what some other group or organization says the convention is. If you don't want to use tabs because you want all your end-of-line comments to line up beautifully, then I have a solution: don't use end-of-line comments (see the next section) and you'll be fine.
 
== Comments ==
 
Add comments that provide some insight into your code, and that help to provide context. Also, because we use tabs, place comments on their own lines, separate from source code, ideally separated by a blank line above and below unless you are verbosely commenting every line of code. This also encourages longer, more descriptive comments that may span multiple lines. If you span multiple lines, use a consistent right margin of 160 characters. Comments help you understand your code when you come back to it a year later, so you are adding descriptive comments for yourself as much as for others. Include information you would find helpful if you had a sudden case of amnesia. They are especially important for free/open source software that needs to be maintained by various people over the years.
 
== Profanity ==
 
Do not place any profanity in source code comments or variable names. It just makes you look unprofessional, silly and incompetent.
 
 
[[Category:QA]]

Revision as of 07:03, December 20, 2014

This section lists the CPU-optimized Funtoo Linux builds currently available for download for amd64-jaguar.

No downloadable stage builds are currently available for this sub-architecture.

.

Architecture and Optimization

The following settings are applied to all stages for this subarch via Funtoo subarch profiles:

CHOSTx86_64-pc-linux-gnu
CFLAGS-march=btver2 -O2 -pipe


The amd64-jaguar (also called AMD Family 16h) subarch supports the AMD jaguar microarchitecture, which is targeted at low-power devices, including notebooks, tablets and small form-factor desktops and servers. It is perhaps most well-known for being the microarchitecture used for the Playstation 4 and Xbox One, which each use custom 8-core Jaguar APUs. Socketed Jaguar APUs use the AM1 socket, and FT3 socket for mobile devices. G-series "system on a chip" (SoC) APUs are available for non-socketed devices such as tablets and embedded system boards.

Desktop Jaguar APUs include the Kabini A-series APUs and Temash E-series APUs, such as the Athlon 5150 and 5350 APUs, and Sempron 2650 and 3850.

Amd64-jaguar subarches use the MOVBE instruction which is not available on amd64-bulldozer, amd64-piledriver or amd64-steamroller. They are thus not instruction-compatible with any of these subarches.

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