x86 Assembly Language Reference Manual

Byte Instructions

Byte Set On Condition (setcc)

setcc 	r/m8

Operation

ConditionTrue: 1 -> r/m8

ConditionFalse: 0 -> rm/8

Description

If the condition is met, setcc stores a one byte at the destination specified by the effective address. If the condition is not met, setcc stores a zero byte. The following table lists the setcc condition options. Similar condition options are separated by commas, followed by the flag condition.

Table 2-10 setcc Condition List


Instruction (`set`+`cc`)	Set Byte If:
`seta, setnbe`	greater, not equal or less than, CF=0 & ZF=0
`setae, setnc, setnb`	equal or greater, not carry, not less than, CF=0
`setb, setc, setnae`	less than carry, carry = 1, not equal or greater than, CF=1
`setbe, setna`	equal or less than, not greater than carry, CF=1 or ZF=1
`sete, setz`	equal, zero, ZF=1
`setg, setnle`	greater, ZF=0 or SF=OF. not equal or less, ZF=1 or SF [ne ] OF
`setge, setnl`	equal or greater, not less, SF = OF
`setl, setnge`	less, not equal or greater, SF [ne ] OF
`setle, setng`	equal or less, not greater, ZF = 1 and SF [ne ] OF
`setne, setnz`	not equal, not zero, ZF = 0
`setno`	not overflow, OF = 0
`setns`	not sign, SF=0
`seto`	overflow, OF = 1
`setpe, setp`	parity even, parity, PF = 1
`setpo, setnp`	parity odd, not parity, PF = 0
`sets`	sign, SF = 1

Example

set(cc) 1(%esi)

Byte Swap (bswap) [486]

bswap	reg[16|32]

Example

Convert little/big endian to big/little endian by swapping bytes.

bswap %ebx