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Another serious reordering problem, misoptimization and gcc
I think it is. Let’s compare – code generated by compiler: d4: ac e6 ldi r26, 0x6C ; 108 d6: b0 e0 ldi r27, 0x00 ; 0 d8: 2c 91...
Saturday, 2 October 2010 - 08:17
Another serious reordering problem, misoptimization and gcc
Ok., I have a solution, volatile in his case did the nice job. I think it’s worth to mention about this function of volatile. Typically we only use it in variables shared...
Saturday, 2 October 2010 - 06:29
Another serious reordering problem, misoptimization and gcc
Of course no. I have attached 64kB of external SRAM to ATMega128. Because ATMega already has 4kB SRAM, so the lowest 4kB of external SRAM are hidden. To access it I need to...
Friday, 1 October 2010 - 17:03
Another serious reordering problem, misoptimization and gcc
So the generated code depends on some mysterious gcc behavior. And it seems that it can be ok (like in your compilation) or wrong (like in mine). But obviously it is another...
Friday, 1 October 2010 - 16:40
cli/sei – virtual problem?
Jan, the problem is that everybody here talks a lot about reordering, but in properly composed program I cannot see the problem. It doesn’t mean that the problem does not exist...
Sunday, 12 September 2010 - 21:10
cli/sei – virtual problem?
I have read the topic, but it is obviously based on a bad example – variable which should be declared as volatile isn’t. So all results are bad, and interpretation is not...
Sunday, 12 September 2010 - 07:03
cli/sei – virtual problem?
Yes, I understand it, but the example form AVR-libc manual works fine. So it should be removed or corrected. And BTW, I’m looking for a working example of such reordering.
Saturday, 11 September 2010 - 20:38
Theoretical problem with accessing to 16-bit register
Ok, so the only 100% legal way of accessing ADC is int a=ADC; everything else could work, but it is not guaranteed? Correct?
Friday, 10 September 2010 - 06:47
Theoretical problem with accessing to 16-bit register
Ok, so as I understood the conclusion is that int a=ADC; is always safe and is a recommended way of reading a 16-bit register. It is implemented as compiler extension. Reading...
Thursday, 9 September 2010 - 11:37
Macros for bit operations
clawson wrote:But what does _BV() actually bring to the party? How is it more readable than the totally standard (1<<n) that all programmers will recognise? At the very...
Wednesday, 18 August 2010 - 10:33
Best Libraries for Graphic LCDs
Doesn’t matter till you have a controller datasheet. You can find some libraries for SED, or graphics LCDs from mobile phones (mostly ILIxxxx). But you can easily write your own...
Saturday, 31 July 2010 - 09:00
Relative Paths in AVR STudio
As aps seems to be a regular XML file it is easy to modify the stored paths, so they reflect the current configuration. I use notepad and find/replace tool. Of course it is only a...
Monday, 26 July 2010 - 12:29

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