19.

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if_icmpge

jump if one integer is greater than or equal to another

Jasmin Syntax
     if_icmpge <label> 
<label> is a label name. To define the location of the label, use the <label> name followed by a colon:
 <label>: 
<label> then becomes associated the address of the following instruction. Labels can only be assigned one location in a method. On the other hand, a single <label> can be the target of multiple branch instructions.

Stack

Before

After
value1
...
value2



Description

if_icmpge pops the top two ints off the stack and compares them. If value2 is greater than or equal to value1, execution branches to the address (pc + branchoffset), where pc is the address of the if_icmpge opcode in the bytecode and branchoffset is a 16-bit signed integer parameter following the if_icmpge opcode in the bytecode. If value2 is less than value1, execution continues at the next instruction.

If you are using Jasmin, branchoffset is computed for you from the address of <label>.

Example

     iload_1         ; push the int value in local variable 1 onto the stack     bipush 2        ; push the int 2 onto the stack     if_icmpge Label ; if the value of local variable 1 >= 2, jump to Label     return          ; return if local variable 1 < 2 Label:     ; execution continues here if local variable 1 >= 2... 
Bytecode

Type

Description
u1
if_icmpge opcode = 0xA2 (162)
s2
branchoffset
See Also

if_icmpeq, if_icmpne, if_icmplt, if_icmpgt, if_icmple

Notes

Addresses are measured in bytes from the start of the bytecode (i.e. address 0 is the first byte in the bytecode of the currently executing method).


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Java Virtual Machine, by Jon Meyer and Troy Downing, O'Reilly Associates


Java Virtual Machine
Java Virtual Machine (Java Series)
ISBN: 1565921941
EAN: 2147483647
Year: 1996
Pages: 171

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