QA·C Help - 2921

	2921	Definite: Left shift operation on expression of unsigned type results in loss of high order bits.

Shift operations

An expression of unsigned type is the subject of a left shift operation and examination of the context indicates that high order bits will always be lost. Is this intended ?

For example:


/*PRQA S 2017,2983,2986,3120,3199,3371,3408 ++*/
/*******************************/
/* OPTIONS: -s int=16          */
/*******************************/
void foo(unsigned int un)
{
    if (un > 0x1000U)
    {
        un = un << 4;         /* 2921 */
    }
}

No MISRA C:2012 Rules applicable to message 2921

See also:

2920 Constant: Left shift operation on expression of unsigned type results in loss of high order bits.
2922 Apparent: Left shift operation on expression of unsigned type results in loss of high order bits.
2923 Suspicious: Left shift operation on expression of unsigned type results in loss of high order bits.

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MISRA C:2012 Compliance Module 1.0
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