X86 INSTRUCTIONS:::::::INTRODUCTION

The different instructions are broken up into groups as follows : Data Transfer Instructions Control Flow Instructions Arithmetic Instructions Logic Instructions Shift and Rotate Instructions Other Instructions x86 Interrupts Conventions The following template will be used for instructions that take no operands: Syntax : Instr The following template will be used for instructions that take 1 operand: Syntax : Instr arg The following template will be used for instructions that take 2 operands. Notice how the format of the instruction is different for different assemblers. Syntax : Instr src, dest #GAS Syntax Instr dest, src #Intel syntax The following template will be used for instructions that take 3 operands. Notice how the format of the instruction is different for different assemblers. Syntax : Instr aux, src, dest #GAS Syntax Instr dest, src, aux #Intel syntax Suffixes Some instructions, especially when built for non-Windows platforms (i.e. Unix, Linux, etc.), require the use of suffixes to specify the size of the data which will be the subject of the operation. Some possible suffixes are: b (byte) = 8 bits w (word) = 16 bits l (long) = 32 bits q (quad) = 64 bits Example of the usage with the mov instruction on a 32-bit architecture, GAS syntax: Syntax : # Store the value F into the eax register movl $0x000F, %eax On Intel Syntax you don't have to use the suffix. Based on the register name and the used immediate value the compiler knows which data size to use. Syntax : MOV EAX, 0x000F