[arm-gnu] an long long problem

[Richard Earnshaw]

On 22/03/12 16:13, zzzh.2007 wrote:
> Hi, all,
>
> I am using sourcery_g++_lite_for_arm_eabi ( version of
> arm-2008q3-66-arm-none-eabi) in Contiki to do some programming, and
> below is my code that have problem:
>
> -----------------------------------------------
> short a,x;
> long long y;
>
> a = (short)rand();
> x = (short)rand() *10000/66536;
>
> y = a*x*x;
>
> printf( "a and x are %d, %d \n", a, x);
> printf( " y is: %lld \n", y);
>
> ----------------------------------------------
> The problem is: the y result is always wrong.
>
> I have no idea why this is happening, any help?
>
> ------------------------------------------------------------------------
> Zhu
> 2012-03-22
>
> ATT00001..txt
>
>
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The most likely reason is that your stack is not correctly aligned.

Why that might be the case you'll have to look into in more detail,
there could be more than one reason.  It might be that your startup code
is incorrect; or it might be that your code is running in an interrupt
context in cortex-m3 and you haven't correctly arranged for the stack to
be re-aligned either by the hardware or the software.

R.

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