2008-01-29 04:44:59 Passing compiler options
Piggebu Piggebu (ANDORRA)
Message: 50265 Hi all
I am trying to augment performance on my BFin 548 EZ Kit. I read that several options passed to the compiler augment performance significantly (such as the simple "-O3" or "-mfast-fp")
Now the maybe simple question: how do I pass these arguments to _all_ programmes compiled in the dist? So I am loking for something like "make menuconfig -03 -mfast-fp" or editing the main "Makefile" (which one?) or setting and exporting a environment variable....
Thanks in advance
Piggebu
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PS: if you feel like: I look for suggestions to handle the following data amount most efficiently (image processing):
- 3 x float[25344]
- 2 x unsinged short[25344]
of which one float array and one unsigned short array stay unchanged (only reading data) and the remining 3 arrays (2 floats and 1 unsigned short) change constantly
I thought of allocating not-kernel-managed SDRAM but it would be nice to use the much faster L1 or L2... but I fear to copy the large data to and from the L1 / L2 would kill again the performance win....
any suggestions?
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2008-01-29 08:11:05 Re: Passing compiler options
Mike Frysinger (UNITED STATES)
Message: 50298 run `make config_menuconfig` and set your CFLAGS under "Blackfin build options"
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2008-01-29 09:00:45 Re: Passing compiler options
Piggebu Piggebu (ANDORRA)
Message: 50302 Hi Mike
thank you for your quick response
I found the "blackfin build options" menu entry but there the only thing I can change is the following
│ │ (FDPIC) Binary format │ │
│ │ [*] Install FLAT shared libraries │ │
│ │ [*] build with stack overflow checking │ │
│ │ [*] install uClinux-dist .config into /root │ │
where do I enter/change the CFLAGS?
regards
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2008-01-29 09:17:45 Re: Passing compiler options
Mike Frysinger (UNITED STATES)
Message: 50303 your checkout is out of date ... you will need to update it to get the relevant changes
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2008-01-29 10:20:13 Re: Passing compiler options
Piggebu Piggebu (ANDORRA)
Message: 50313 ups, I'll check it out tomorrow then
thanks for the help
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2008-01-30 03:12:50 Re: Passing compiler options
Piggebu Piggebu (ANDORRA)
Message: 50344 Mike,
I downloaded the latest trunk (6h ago) of uclinux-dist but no changes in the menuconfig menu appeared...still looks the same as above in "blackfin build options". Maybe I have overseen something?
regards
Piggebu
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2008-01-30 07:53:22 Re: Passing compiler options
Mike Frysinger (UNITED STATES)
Message: 50373 are you using the branch or trunk ?
trunk should look like:
Blackfin build options --->
(-g -O2) User/Lib CFLAGS
assuming you have the options under "Debug builds" turned off
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2008-01-30 10:55:14 Re: Passing compiler options
Cameron Barfield (UNITED STATES)
Message: 50378 Piggebu --
Just a note: you may need to update your toolchain, as well, if you want to use those CFLAGS. I had to check out the latest from SVN to get those flags working.
See:
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2008-01-31 10:04:32 Re: Passing compiler options
Piggebu Piggebu (ANDORRA)
Message: 50474 Mike, Cameron
Erm, I found out that my scripts to get the new trunk and install it were slightly errornous... so I only thought I had the most recent version... Sorry for all the noise around that problem...
I found now the option and I am currently compiling the new dist with these new compiler flags
Thanks for the help
Piggebu
PS: Cameron: I am no expert, but I think the toolchain has not much to do with it at this stage. I think I can call "make menuconfig" even without having a toolchain installed... It only comes into the game when "make" is called... But anyway, as mentioned the problem was in the update scripts i wrote ;-)