IA-32架构和Intel 64架构的区别

摘自Intel的手册（Intel 64 and IA-32 Architectures Software Developer’s Manual Volume 1:Basic Architecture）：

IA-32 architecture is the instruction set architecture and programming environment for Intel’s 32-bit microprocessors. Intel 64 architecture is the instruction set architecture and programming environment which is the superset of Intel’s 32-bit and 64-bit architectures. It is compatible with the IA-32 architecture.

看来，IA-32架构和Intel 64架构主要是针对指令集和指令的执行环境而言的，其中Intel 64架构通过引入一种工作模式（IA-32e）来兼容在IA-32架构上运行的程序。