JVM, Class Files, and the CLEmitter - Introduction to Compiler Construction in a Java World - page 334

Mnemonic Operation Operand Stack

if_icmplt Branch if int comparison
value1 < value2 true

;value1;value2 )

if_icmpgt Branch if int comparison
value1 > value2 true

;value1;value2 )

if_icmple Branch if int comparison
value1 value2 true

;value1;value2 )

if_icmpge Branch if int comparison
value1 value2 true

;value1;value2 )

if_acmpeq Branch if reference com-
parison value1 == value2
true

;value1;value2 )

if_acmpne Branch if reference com-
parison value1 != value2
true

;value1;value2 )

goto Branch always

No change

goto_w Branch always (wide in-
dex)

No change

jsr Jump subroutine

) ;address

jsr_w Jump subroutine (wide in-
dex)

) ;address

The above instructions can be added to the code section of a method by sending the
CLEmitter instance the following message:

publicvoidaddBranchInstruction(intopcode,
Stringlabel)

where opcode is the mnemonic of the instruction to be added, and label is the target
instruction label.

Mnemonic Operation Operand Stack

ret Return from subroutine

No change

The above instruction can be added to the code section of a method by sending the
CLEmitter instance the following message:

publicvoidaddOneArgInstruction(intopcode,
intarg)

where opcode is the mnemonic of the instruction to be added, and arg is the index of the
local variable containing the return address.

Mnemonic Operation Operand Stack

lookupswitch Access jump table by key
match and jump

;key )

The above instruction can be added to the code section of a method by sending the
CLEmitter instance the following message: