Difference between revisions of "Assembler:Commands:SUB"
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'''command''' sub ''destination'', ''source'' | '''command''' sub ''destination'', ''source'' | ||
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The SUB instruction performs integer subtraction. It evaluates the result for both signed and unsigned integer operands and sets the '''OF''' and '''CF''' flags to indicate an overflow in the signed or unsigned result, respectively. The '''SF''' flag indicates the sign of the signed result. | The SUB instruction performs integer subtraction. It evaluates the result for both signed and unsigned integer operands and sets the '''OF''' and '''CF''' flags to indicate an overflow in the signed or unsigned result, respectively. The '''SF''' flag indicates the sign of the signed result. | ||
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sub [SomeSymbol],eax | sub [SomeSymbol],eax | ||
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Latest revision as of 16:06, 3 January 2018
command sub destination, source
Subtracts the source from the destination.
The OF, SF, ZF, AF, PF, and CF flags are set according to the result.
destination = destination - source
Subtracts the second operand (source operand) from the first operand (destination 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, register, or 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 SUB instruction performs integer subtraction. It evaluates the result for both signed and unsigned integer operands and sets the OF and CF flags to indicate an overflow in the signed or unsigned result, respectively. The SF flag indicates the sign of the signed result.
Command Parameters[edit]
| Parameter | Description |
|---|---|
| destination | The destination operand |
| source | The source operand |
Examples[edit]
sub al,1
sub ax,1
sub eax,1
sub rax,-1
sub [eax],0x9
sub [rax],1
sub [rax],rsi
sub eax,[rax]
sub rax,[rax]
sub [SomeSymbol],1
sub [SomeSymbol],eax
