QA·C Help - 2920

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

Shift operations

A left-shift operation is being performed on a constant expression of unsigned integer type and this will result in the loss of some non-zero high-order bits. Is this intended ?

Example:


/*PRQA S 1279,2017,2022,2982,2984,3120,3198,3211,3301,3408 ++*/

unsigned long ula;

extern void foo(void)
{
    ula = 0x00F00000UL << 8;            /*      */
    ula = 0x00F00000UL << 9;            /* 2920 */
    ula = 0x0F000000UL << 4;            /*      */
    ula = 0x0F000000UL << 5;            /* 2920 */
    ula = 0xF0000000UL << 0;            /*      */
    ula = 0xF0000000UL << 1;            /* 2920 */
}

See also:

2921 Definite: 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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