control flow graph可以属于机器视角 1.2 Basic Block(基本块) 在中间表示中,一般使用 Control Flow Graphs,而CFG中使用Basic Blocks来进行程序的中间表示。 Basic Blocks:始终连续执行的指令序列。 一般只在一个基本块的结尾有一个分支,控制流也只能通过一个块的第一个指令进入Basic Blocks。 构造基本块的目的:优化...
原文: In a control-flow graph each node in the graph represents a basic block, i.e. a straight-line piece of code without any jumps or jump targets; jump targets start a block, and jumps end a block. Directed edges are used to represent jumps in the control flow. There are, in mos...
给定可执行代码块 OriginalOperation的控制流图表示形式。 此图包含一组 BasicBlock,其中包含一个入口块、零个或多个中间基本块和一个退出块。 每个基本块包含零个或多个 Operations , ControlFlowBranch 并且显式 () 到其他基本块 () 。
因此通过编写analysis pass,提取control flow是十分关键的步骤。除此之外,analysis pass的编写技巧包括了对ir进行查找、遍历等,熟练掌握是后续操作的必要条件。 前一篇文章已经介绍了Analysis Pass的7个基本操作,本文介绍如何编写一个可生成CFG(Control Flow Graph)的Analysis Pass。 首先要明确CFG是一种特殊的Graph,是...
control flow graph Control Flow Graphs Nodes Statements or Basic Blocks (Maximal sequence of code with branching only allowed at end) Edges Possible transfer of control Example:if P then S1 else S2 S3 P S1S2 S3 CFG P predecessor of S1 and S2 S1, S2 sucessors of P Finding Basic Blocks ...
Control-Flow Graph The simplest unit of control flow in a program is abasic block—a maximallength sequenceof straightline, or branch-free, code. A basic block is a sequence of operations that always execute together, unless an operation raises an exception. Control always enters a basic block...
cfNodes.Add(exceptionalExit);// Create graph nodeslabelToCfNode.Clear(); Dictionary<ILNode,ControlFlowNode> astNodeToCfNode =newDictionary<ILNode,ControlFlowNode>();List<ILLabel> listLabels =null;foreach(ILBasicBlock node in nodes) {ControlFlowNodecfNode =newControlFlowNode(index++,null, Cont...
A control flow graph can depict how different program units or applications process information between different ends in the context of the system. There are many advantages associated with a control flow graph. It can easily summarize the information per each basic block. It can easily locate ...
Usually, the control sequences are expressed as a control-flow graph (CFG), where each node represents a basic block of code (statement or instruction) while each directed edge indicates a possible flow of control between two nodes. Data-flow analysis A data-flow analysis [14] is a ...
In this case a basic block is a block of instructions, thatdo not alter the control flow within the current function. We (falsely) assume thatcallinstructions always return to the instruction after saidcallinstruction so the control flow of the block is not interrupted. Additionally a basic blo...