ARM Thumb mode size increase by enabling -mthumb mode

[naveen yadav]

Hi Andrew,

Thanks for your idea,

I have found the reason. the reason is debug symbols,
I need to either run strip command or i can verify size by  gcc-size
command to check text section reduction.

Best Regards
Naveen

On Mon, Aug 10, 2009 at 10:18 PM, Andrew Haley<aph@redhat.com> wrote:
> naveen yadav wrote:
>> Hi Andrew,
>>
>>
>> I want to know in which cases size of binary or .o file increase by
>> enabling -mthumb mode.
>>
>> I have observed in one open source program iozone. i found that if i
>> pass -mthumb option size of binary increases.
>>
>> I do not understand why ..
>>
>> will you pls help
>
> Sure, I'll be glad to but you have to help too.  As in, what is the file,
> and what are the differences in the assembly language source.
>
> You have the answers, but I don't.
>
>> On Mon, Aug 10, 2009 at 9:51 PM, Andrew Haley<aph@redhat.com> wrote:
>>> naveen yadav wrote:
>>>
>>>> we have observed few points,
>>>>
>>>> 1. In Some cases size of .o file increase in thumb mode. when i
>>>> dissamble it i found all instruction are 16 bit.In what cases size increases?
>>> Did you not find out by looking at gcc's output?  What did you
>>> see?
>>>
>>>> 2. How much size will be reduce as compared with ARM mode.?
>>>> 3. Code reduction depends on what ?
>>>>
>>>> 4. How much performance effect with Arm and Thumb mode.
>>> See www.arm.com/pdfs/Thumb-2CoreTechnologyWhitepaper-Final4.pdf
>>>
>>> Andrew.
>>>
>>>
>
>