Assembler:Commands:COMISS
Revision as of 15:43, 25 March 2022 by Hanslhansl (talk | contribs)
command comiss operand1, operand2
Compares the single-precision floating-point (single-fp) value in the low doubleword of the first operand with the single-fp value in the low doubleword of the second operand and sets the status flags in the (E)FLAGS register.
The CF, ZF and PF flags are set according to the result (unordered, greater than, less than, or equal). The OF, SF and AF flags are set to 0. The unordered result is returned if either source operand is a NaN (QNaN or SNaN).
Command Parameters
| Parameter | Description |
|---|---|
| operand1 | The first operand to compare. Must be a XMM register. |
| operand2 | The second operand to compare. May be an XMM register or a 32 bit memory location |
Result
| Parameter | Description |
|---|---|
| operand1 < operand2 | ZF = 0, PF = 0, CF = 1 |
| operand1 = operand2 | ZF = 1, PF = 0, CF = 0 |
| operand1 > operand2 | ZF = 0, PF = 0, CF = 0 |
| unordered | ZF = 1, PF = 1, CF = 1 |
Examples
comiss xmm2,xmm5
comiss xmm2,[eax]
comiss xmm0,[00123ABC]
