什么是有效地址？
What is an effective address?
在读取 Intel 64 and IA-32 Architectures Software Developer’s Manual 时，LEA 指令的操作部分（加载有效地址）使用称为 EffectiveAddress(SRC) 的计算，该计算未在其他任何地方定义。
有效地址的定义是什么，EffectiveAddress(SRC)有什么作用？
同一文档的第 3.7.5 节（指定偏移量）指出：
The offset part of a memory address can be specified directly as a
static value (called a displacement) or through an address computation
made up of one or more of the following components:
- Displacement — An 8-, 16-, or 32-bit value.
- Base — The value in a general-purpose register.
- Index — The value in a general-purpose register.
- Scale factor — A value of 2, 4, or 8 that is multiplied by the index value.
The offset which results from adding these components is called an
effective address. Each of these components can have either a positive
or negative (2s complement) value, with the exception of the scaling
factor.
EffectiveAddress 使用以下方法计算有效地址：
Base + (Index*Scale) + Displacement
有效地址是段基地址的偏移量。当您在保护模式（32 位模式）下看到类似 call 0x80000000 的内容时，CPU 将 0x80000000 添加到 CS 段寄存器指向的段的基地址。
在64位模式下，它等于线性地址，因为分段基本上被禁用了。
在读取 Intel 64 and IA-32 Architectures Software Developer’s Manual 时，LEA 指令的操作部分（加载有效地址）使用称为 EffectiveAddress(SRC) 的计算，该计算未在其他任何地方定义。
有效地址的定义是什么，EffectiveAddress(SRC)有什么作用？
同一文档的第 3.7.5 节（指定偏移量）指出：
The offset part of a memory address can be specified directly as a static value (called a displacement) or through an address computation made up of one or more of the following components:
- Displacement — An 8-, 16-, or 32-bit value.
- Base — The value in a general-purpose register.
- Index — The value in a general-purpose register.
- Scale factor — A value of 2, 4, or 8 that is multiplied by the index value.
The offset which results from adding these components is called an effective address. Each of these components can have either a positive or negative (2s complement) value, with the exception of the scaling factor.
EffectiveAddress 使用以下方法计算有效地址：
Base + (Index*Scale) + Displacement
有效地址是段基地址的偏移量。当您在保护模式（32 位模式）下看到类似 call 0x80000000 的内容时，CPU 将 0x80000000 添加到 CS 段寄存器指向的段的基地址。
在64位模式下，它等于线性地址，因为分段基本上被禁用了。