There are a whole bunch of JSON v XML posts out there. So, I will not rehash the various arguments on which is better. However, we needed to select a file format to store configuration information. To make things convenient, we decided to use the Boost::Property_Tree library. So, this is Read more…
After lots of testing i found certain variances that can help in speeding up code. These are a few simple practices. Know your target. If the T3RAS core you’re compiling for contains hardware features like multiplier and barrel shifting, include it when compiling your code using -mattr=barrel,mul . Both instructions Read more…
The T3RAS backend in llvm is based on the microblaze 6.3 architecture set but without hardware support for floating points and without hardware division. The T3RAS backend contains 3 variants (T3RAS1T, T3RAS2T, T3RAS4T) which is described below. To list all variants and features of T3RAS, simply run: llvm-as < /dev/null Read more…
While i was successful in making sure the backend appeared with the right name and features that were needed, there were still many shortcomings that needed to be addressed. After a while of copying, modifying and adapting code, I was finally able to change the names and variants. Instead of Read more…
After finally managing to port an architecture i thought i’d share the steps as there isnt a clear or simple guide on adding your own backend to LLVM. It should be noted that at this time of writing the LLVM documentation at llvm.org is outdated (also mentioned on their website). Read more…
Finally managed to compile LLVM and clang for microblaze. I find using configure –target= or -target doesnt work while using –enable-targets=”mblaze” worked. I found the documentation to be very poor on this and does not mention anything about the other options available in configure such as using –enable-targets. I also Read more…
Continue from my previous post, LLVM: Compiling FreeRTOS with LLVM (Part 1). Anybody who might have some basic skills in programming, creating Makefiles especially, must be laughing hysterically if they come across and read my previous post in this topic. When I google the phrase “Compiling freertos with llvm” or Read more…
It is about two more weeks before my internship at Aeste ends. Yesterday, I finished my task of cleaning up LLVM floating points instructions and cache instructions. What I did was just hunt all these unwanted instructions inside AEMB target directory files and remove it without damaging the files or Read more…
My recent task is to clean up the instructions from LLVM code. One must wonder why do I need to clean up the instructions, well perhaps the definition of my recent task was not adequately explain here. AEMB is considered as binary compatible to the Xilink Microblaze (Wikipedia link), however Read more…
In LLVM system compiler, there is an option in the command command -mattr called target specific attributes. You may check each target attributes by using this command. llvm-as < /dev/null || llc -march=aemb -mattr=help note that -march=aemb is to select target architecture, in my case, aeMB. A list of attributes Read more…