..., key
...
| lookupswitch | |
| <0-3 byte pad> | |
| defaultbyte1 | |
| defaultbyte2 | |
| defaultbyte3 | |
| defaultbyte4 | |
| npairs1 | |
| npairs2 | |
| npairs3 | |
| npairs4 | |
| match-offset pairs... |
Forms
lookupswitch = 171 (0xab)
Description
A lookupswitch is a variable-length instruction. Immediately after the lookupswitch opcode, between zero and three null bytes (zeroed bytes, not the null object) are inserted as padding. The number of null bytes is chosen so that the defaultbyte1 begins at an address that is a multiple of four bytes from the start of the current method (the opcode of its first instruction). Immediately after the padding follow a series of signed 32-bit values: default, npairs, and then npairs pairs of signed 32-bit values. The npairs must be greater than or equal to 0. Each of the npairs pairs consists of an int match and a signed 32-bit offset. Each of these signed 32-bit values is constructed from four unsigned bytes as (byte1 << 24) | (byte2 << 16) | (byte3 << 8) | byte4.
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Java Virtual Machine Specification (HTML generated by dkramer on February 25, 1997)
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