[En-Nut-Discussion] Fwd: Not fixed!!!: Re: confirmed!!! Re: NutOS 4.4.0 on ARM7: possibly bug in NutEnterCritical / NutExitCritical

[Harald Kipp]

duane ellis schrieb:
> 
> Compile the following code snippet with  "arm-elf-gcc -O2 -S foo.c", 
> look at the result "foo.s" file.
> GCC in the UNSAFE condition optimizes the two additions into a single +2 
> addition.
> 
> The difference is "memory" or "not".

Now I got it. Yes, you are perfectly right. Your sample code is somewhat 
unrealistic, because I wouldn't care if in this case the variable is 
decremented twice after enabling interrupts. But it clearly demonstrates 
the problem.

Harald