CSAPP translation summary (C/N) page 21

如果处理器可以达到比一个周期一条指令更快的执行速率,就称之为超标量处理器. 大多数现代处理器都支持超标量操作.

If the processors can sustain exection rates faster than per cycle execution one instruction that know as superscalar processors. Most of modern processors support superscalar processors.

在最低层次上,许多现代处理器拥有特殊的硬件,允许一条指令产生多个可以并执行的操作,这种方式称为单指令 多数据,即SIMD并行. 提供这些SIMD指令是为了提高处理影像 声音 和 视屏数据应用的执行速度. 有些编译器会试图从C程序中自动抽取SIMD并行性,但更可靠的方法是用编辑器支持的特殊的向量数据类型来写程序, 比如GCC就支持向量数据类型.

At the lowest level, many morden processors have special hardware, allow one instruction have multiple operation in parallel, this style known as single-instruction multiple-data, or “SIMD”. provides these SIMD instruction in order to improve execution speed of image, sound, and video data. Some compilers try automatically extract SIMD parallelism form C program, a more reliable method is use vector data type write program of compilers support it such as GCC.

抽象的使用是计算机科学中最为重要的概念之一.

The use of abstraction is one of the important concept in computer science.

在处理器里,指令集架构提供了对实际处理器硬件的抽象.使用这个抽象,机器代码程序表现得就好像运行在一个一次只执行一条指令的处理器上.

On the processor side, the instruction set architecture provides an abstraction of actual processor hardware. Use this abstraction, a machine-code program likes running on a processor that just execute on instruction at a time.