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

Inspection ID: IncompatibleMask

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 2025.3

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.3, Qodana for JVM 2025.3,

Last modified: 03 December 2025