现代计算机在冯诺伊曼模型的基础理念上,设计了不同的指令集架构ISA,这些指令集架构ISA中规定了计算机的各个部件(内存、执行单元、控制单元等)的具体实现规范(包括地址空间、寻址能力、寄存器个数和用途)和执行的工作(指令)。 所以说,指令集架构ISA就是在冯诺伊曼模型的基础上制定的各种计算机设计规范。 接下来我们就会...
E.g, x86 ISA: 多媒体拓展 (MMX), 后面又有支持SIMD的SSE和AVX指令集拓展。 E.g, VAX ISA: 一个切换程序上下文的指令 指令支持的操作数类型,也是有差别。其中仍然是软件和硬件复杂度之间的取舍问题。 比如:RISC architectures vs. Intel 432 早期的RISC只支持整数操作,如果有浮点数的需要需自行去用整形操作...
An in-depth look at how to disassemble the x86 instruction set, and how to put it to good use in your own code injections Introduction When starting out as a reverse engineer or malware analyst, it is often tempting to trust your disassembler to correctly resolve the various bytes into code...
x86-64 CISC instructions are not executed by the hardware, but compiled into microcode; then, the CPU executes the microcode.1 RISC architecture, true to the name, limits the number of instructions. RISC is a load-store architecture. RISC ISA includes two instructions, one to fetch data into...
x86InstructionSet Architecture Comprehensive32/64-bitCoverage FirstEdition AlsobyTomShanley HEAVEN’SFAVORITE —ANovelofGenghisKhan— Book1,ASCENT:THERISEOFCHINGGISKHAN Book2,DOMINION:DAWNOFTHEMONGOLEMPIRE MINDSHARETECHNICALTRAINING Pleasevisit.mindshareforacompletedescriptionofMind- ...
For example, the IBM Stretch [stretch], developed in the late 1950s, had an ISA with 32-bit and 64-bit instructions, where some of the 32-bit instructions were compressed versions of the full 64-bit instructions. Stretch also employed the concept of limiting the set of registers that ...
The x86mf instruction instructs processor 104 to move a value in a specified x86 integer register to a specified 64 bit integer register. Processor 104 then performs operations using the value in the 64 bit integer register. When processor 104 decodes and executes move to instruction 214, proce...
Nowadays, X86 CPU all have superscalar computing ability. Superscalar architecture can fetch, execute and commit more than one instruction per cycle. And it helps a lot to explore more instruction level parallelism. If a superscalar processor fetches instructions inefficiently, its performance speedup ...
open and standarized procedure for x86 instruction set extensions. Af first sight, this may seem a discussion that does not concern most of us. After all, the poor souls that have to program the insanely complex x86 compilers will take care of the complete chaos called "the x86 ISA", ...
不同的指令通过操作码进行区分,不同的ISA可以定义不同数量的操作码,表示该机器支持的操作数量,比如LC-3中操作码仅有4位bit,因此它只支持最多16种不同的操作;而MIPS中的操作码有6位bit,因此它可以支持最多64中不同的操作。并且我们之前说过,根据操作码的不同,可以将LC-3和MIPS中的指令分为三种类型:操作型指...