Difference between revisions of "Assembler:Commands:LEA"
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'''command''' lea ''destination'', ''source'' | '''command''' lea ''destination'', ''source'' | ||
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Computes the effective address of the second operand (the source operand) and stores it in the first operand (destination operand). The source operand is a memory address (offset part) specified with one of the processors addressing modes; the destination operand is a general-purpose register. The address-size and operand-size attributes affect the action performed by this instruction, as shown in the following table. The operand-size attribute of the instruction is determined by the chosen register; the address-size attribute is determined by the attribute of the code segment. | Computes the effective address of the second operand (the source operand) and stores it in the first operand (destination operand). The source operand is a memory address (offset part) specified with one of the processors addressing modes; the destination operand is a general-purpose register. The address-size and operand-size attributes affect the action performed by this instruction, as shown in the following table. The operand-size attribute of the instruction is determined by the chosen register; the address-size attribute is determined by the attribute of the code segment. | ||
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lea rax,[rax+rdx*8] | lea rax,[rax+rdx*8] | ||
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Latest revision as of 15:48, 3 January 2018
command lea destination, source
Load Effective Address
Computes the effective address of the second operand (the source operand) and stores it in the first operand (destination operand).
This is also use for some arithmetic.
lea eax,[eax+64*5] // eax = eax + (100 * 5) lea eax,[eax+edx*5] // eax = eax + (edx * 5)
Computes the effective address of the second operand (the source operand) and stores it in the first operand (destination operand). The source operand is a memory address (offset part) specified with one of the processors addressing modes; the destination operand is a general-purpose register. The address-size and operand-size attributes affect the action performed by this instruction, as shown in the following table. The operand-size attribute of the instruction is determined by the chosen register; the address-size attribute is determined by the attribute of the code segment.
Command Parameters[edit]
| Parameter | Description |
|---|---|
| destination | The destination operand |
| source | The source operand |
Examples[edit]
lea ax,[ax+5*2]
lea ax,[ax+dx*2]
lea eax,[eax+5*4]
lea eax,[eax+edx*4]
lea rax,[rax+5*8]
lea rax,[rax+rdx*8]
