Increment local int variable by constant

Format

iinc_w

index

byte1

byte2

Forms

iinc_w = 151 (0x97)

Stack

No change

Description

The index is an unsigned byte. Both index and index + 1 must be valid indices into the local variables of the current frame ( Section 3.5, Frames). The local variables at index and index + 1 together must contain an int. The immediate unsigned byte1 and byte2 values are assembled into an intermediate short where the value of the short is (byte1 « 8) | byte2. The intermediate value is then sign-extended to an int const. The int contained in the local variables at index and index + 1 is incremented by const.

Notes

If a virtual machine does not support the int data type, the iinc_w instruction will not be available.