X86 Architecture

Intel’s Dilemma All (most) software uses CISC code and needs a CISC ISA RISC is more efficient, CISC is cumbersome Pentium CISC Input machine code Translation CISC to RISC Execution as RISC

Pentium Architecture CISC RISC

Pentium Pipeline

// Test1.cpp : Defines the entry point for the console application. #include "stdafx.h" int _tmain(int argc, _TCHAR* argv[]) { int x,y,z; x = 3; 0041137E mov dword ptr [x],3 puts 3 into memory at address x y = 5; 00411385 mov dword ptr [y],5 puts 5 into memory at address y z = x + y; 0041138C mov eax,dword ptr [x] moves data at address x into eax 0041138F add eax,dword ptr [y] adds data at address y to eax 00411392 mov dword ptr [z],eax moves contents of eax to memory at y return 0; 00411395 xor eax,eax }