Alias Analysis Infrastructure in LLVM

@@ -58,30 +57,28 @@

-Alias Analysis (or Pointer Analysis) is a technique which attempts to determine -whether or not two pointers ever can point to the same object in memory. -Traditionally, Alias Analyses respond to a query with either a Alias Analysis (or Pointer Analysis) is a technique which attempts to +determine whether or not two pointers ever can point to the same object in +memory. Traditionally, Alias Analyses respond to a query with either a Must, May, or No alias response, indicating that two pointers do point to the same object, might point to the same object, or are -known not to point to the same object. -

-The AliasAnalysis class is the +known not to point to the same object.

+ +

The AliasAnalysis class is the centerpiece of the LLVM Alias Analysis related infrastructure. This class is the common interface between clients of alias analysis information and the implementations providing it. In addition to simple alias analysis information, this class exposes Mod/Ref information from those implementations which can provide it, allowing for powerful analyses and transformations to work well -together. -

-This document contains information necessary to successfully implement this +together.

+ +

This document contains information necessary to successfully implement this interface, use it, and to test both sides. It also explains some of the finer points about what exactly results mean. If you feel that something is unclear or should be added, please let me -know. -

+know.

@@ -91,21 +88,20 @@ know.

-The AliasAnalysis class defines -the interface that Alias Analysis implementations should support. This class -exports two important enums: AliasResult and ModRefResult -which represent the result of an alias query or a mod/ref query, -respectively. -

-The AliasAnalysis interface exposes information about memory, represented in + +

The AliasAnalysis class +defines the interface that Alias Analysis implementations should support. This +class exports two important enums: AliasResult and +ModRefResult which represent the result of an alias query or a mod/ref +query, respectively.

+ +

The AliasAnalysis interface exposes information about memory, represented in several different ways. In particular, memory objects are represented as a starting address and size, and function calls are represented as the actual call or invoke instructions that performs the call. The AliasAnalysis interface also exposes some helper methods which allow you to get -mod/ref information for arbitrary instructions. -

+mod/ref information for arbitrary instructions.

-- 2.34.1