On 03/14/2011 03:14 PM, Andrew Haley wrote:
> On 03/14/2011 12:02 PM, Sebastian Huber wrote:
>> Hello,
>>
>> the object file bpabi.o is part of libgcc. It is compiled with the option
>> -fexceptions. Does anyone know why we need exceptions here?
>
> __divdi3 can throw an exception. I don't know whether it does on ARM,
> but it does on other processors.
>
> Andrew.
Thanks for the hint. How can an assembler or C function throw an exception? I
am absolutely not sure how this low-level stuff works in detail, but it seems
to me from a look at libgcc/Makefile.in that this -fexceptions is used for all
targets? I currently try to prepare a RTEMS GCC for ARM to use the ARM EABI
version 5. Now I have the problem that an innocent looking
int64_t f(int64_t a, int64_t b)
{
return a / b;
}
will pull in the hole unwind mechanic that accounts for 10kByte of Thumb code.
This might be a problem for small target systems.
--
Sebastian Huber, embedded brains GmbH
Address : Obere Lagerstr. 30, D-82178 Puchheim, Germany
Phone : +49 89 18 90 80 79-6
Fax : +49 89 18 90 80 79-9
E-Mail : sebastian.huber@xxxxxxxxxxxxxxxxxx
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