Hello:
We encountert a problem with the optimization in Code Composer 4.1.3, 5.2.1, 6.2.5, 6.4.6, LTS 15.12.0. Is it known and how we get arround it?
struct CCanQueue
{
unsigned short * Pending_In;
unsigned short * Pending_Out;
} ;
unsigned short Spi_Out_Queue_Ctr;
void error_example ( struct CCanQueue * pQueue , short unsigned *CanBuf )
{
short unsigned nummsg ;
short unsigned NumWords ;
short unsigned * pQExpected ;
long nWords2Send ;
nWords2Send = (long) pQueue->Pending_In - (long) pQueue->Pending_Out ;
/*=============================================================================================
When this code is compiled with the optimizer, the code below "if ( nWords2Send < 0 )" is ignored.
When the nWords2Send parameter is defined as "long volatile" the compiler does not ignore it!
but we don't know it until we we have a failure!
==============================================================================================*/
if ( nWords2Send < 0 )
{
nWords2Send += 160 ; // Cyclic buffer roll
}
/*=============================================================================================
End of optimizer ignored code
==============================================================================================*/
nWords2Send = _IQsat ( (long) (58 - Spi_Out_Queue_Ctr ) , (long)nWords2Send , 0 ) ;
nummsg = (short unsigned)_IQ16mpy( nWords2Send ,13108 ) ; // 13108 is _IQ16(0.2) + epsilon
NumWords = nummsg * 5 ;
pQExpected = pQueue->Pending_Out + NumWords ;
if ( pQExpected >= (CanBuf + 160) )
{
pQExpected -= 160 ;
}
pQueue->Pending_Out = pQExpected ;
}
Regards Arye
