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Re: default mtp in case arm
On Tue, Jan 4, 2011 at 4:33 AM, Ian Lance Taylor <iant@google.com> wrote:
> raju goruganti <raju.goruganti@gmail.com> writes:
>
>> Just I want to know ,Whether the dafult for '-mtp' is soft or not?
>>
>> If yes ,Why it has been ?choosen as soft?
>>
>> I think mtp=cp15 ?is more efficient(I figured this out after some
>> google -search).
>
> From the friendly manual:
>
> `-mtp=NAME'
> ? ? Specify the access model for the thread local storage pointer.
> ? ? The valid models are `soft', which generates calls to
> ? ? `__aeabi_read_tp', `cp15', which fetches the thread pointer from
> ? ? `cp15' directly (supported in the arm6k architecture), and `auto',
> ? ? which uses the best available method for the selected processor.
> ? ? The default setting is `auto'.
>
> Ian
>
Thank you for your reply,
Yes,default is auto, and auto chooses soft in latest gcc.