Intel Pentium CPU Instruction Set Reference
ADD instruction - Add
| Code |
Mnemonic |
Description |
| 04 ib |
ADD AL, imm8 |
Add imm8 to AL |
| 05 iw |
ADD AX, imm16 |
Add imm16 to AX |
| 05 id |
ADD EAX, imm32 |
Add imm32 to EAX |
| 80 /0 ib |
ADD r/m8, imm8 |
Add imm8 to r/m8 |
| 81 /0 iw |
ADD r/m16, imm16 |
Add imm16 to r/m16 |
| 81 /0 id |
ADD r/m32, imm32 |
Add imm32 to r/m32 |
| 83 /0 ib |
ADD r/m16, imm8 |
Add sign-extended imm8 to r/m16 |
| 83 /0 ib |
ADD r/m32, imm8 |
Add sign-extended imm8 to r/m32 |
| 00 / r |
ADD r/m8, r8 |
Add r8 to r/m8 |
| 01 / r |
ADD r/m16, r16 |
Add r16 to r/m16 |
| 01 / r |
ADD r/m32, r32 |
Add r32 to r/m32 |
| 02 / r |
ADD r8, r/m8 |
Add r/m8 to r8 |
| 03 / r |
ADD r16, r/m16 |
Add r/m16 to r16 |
| 03 / r |
ADD r32, r/m32 |
Add r/m32 to r32 |
Description
Adds the first operand (destination operand) and the second operand (source operand) and stores the result in the destination operand. The destination operand can be a register or a memory location; the source operand can be an immediate, a register, or a memory location. (However, two memory operands cannot be used in one instruction.) When an immediate value is used as an operand, it is sign-extended to the length of the destination operand format.
The ADD instruction does not distinguish between signed or unsigned operands. Instead, the processor evaluates the result for both data types and sets the OF and CF flags to indicate a carry in the signed or unsigned result, respectively. The SF flag indicates the sign of the signed result.
| Operands |
Bytes |
Clocks |
| reg, reg |
2 |
1 |
UV |
| mem, reg |
2 + d(0, 2) |
3 |
UV |
| reg, mem |
2 + d(0, 2) |
2 |
UV |
| reg, imm |
2 + i(1, 2) |
1 |
UV |
| mem, imm |
2 + d(0, 2) + i(1, 2) |
3 |
UV ( not pairable if there is a displacement and immediate) |
| acc, imm |
1 + i(1, 2) |
1 |
UV |
Flags
| ID |
unaffected |
DF |
unaffected |
| VIP |
unaffected |
IF |
unaffected |
| VIF |
unaffected |
TF |
unaffected |
| AC |
unaffected |
SF |
sets according to the result. |
| VM |
unaffected |
ZF |
sets according to the result. |
| RF |
unaffected |
AF |
sets according to the result. |
| NT |
unaffected |
PF |
sets according to the result. |
| IOPL |
unaffected |
CF |
sets according to the result. |
| OF |
sets according to the result. |
