Incompatible bitwise mask operation

Reports bitwise mask expressions which are guaranteed to evaluate to true or false.

The inspection checks the expressions of the form (var & constant1) == constant2 or (var | constant1) == constant2, where constant1 and constant2 are incompatible bitmask constants.

Example:

  // Incompatible mask: as the mask ends in 00,
  // the result could be 0x1200 but not 0x1234
  if ((mask & 0xFF00) == 0x1234) {...}

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

-IncompatibleBitwiseMaskOperation

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Java | Bitwise operation issues

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection -IncompatibleBitwiseMaskOperation

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025