dcmpg : compare two doubles (1 on NaN) : index : visitInsn()

Description

This takes two double-precision floating point numbers off the operand stack and compares them, using IEEE 754 rules.

If the two numbers are the same, the int 0 is pushed onto the stack. If value2 is greater than value1, the int 1 is pushed onto the stack. If value1 is greater than value2, -1 is pushed onto the stack. If either numbers is NaN, the int 1 is pushed onto the stack. +0.0 and -0.0 are treated as equal.

Example

dload_1       ; push the double in local variable 1
dconst_0      ; push the double 0.0 onto the stack
dcmpg         ; compare the two numbers
; The integer result on the stack is:
;     0 if local variable 1 equals 0
;     -1 if local variable 1 is less than 0
;     1 if local variable 1 is greater than 0

Notes

This instruction is identical to dcmpl except for the treatment of NaN.

See also

lcmp fcmpl fcmpg dcmpl

Stack

Before	After
value1-word1	int-result
value1-word2	...
value2-word1	...
value2-word2	...
...	...

Bytecode

Type	Description
u1	dcmpg opcode = 0x98 (152)