This file defines various utility types and functions useful to summary-based alias analysis. More...
#include "llvm/ADT/DenseMapInfo.h"#include "llvm/ADT/Optional.h"#include "llvm/ADT/SmallVector.h"#include "llvm/IR/CallSite.h"#include <bitset>
Go to the source code of this file.
Classes | |
| struct | llvm::cflaa::InterfaceValue |
| We use InterfaceValue to describe parameters/return value, as well as potential memory locations that are pointed to by parameters/return value, of a function. More... | |
| struct | llvm::cflaa::ExternalRelation |
| We use ExternalRelation to describe an externally visible aliasing relations between parameters/return value of a function. More... | |
| struct | llvm::cflaa::ExternalAttribute |
| We use ExternalAttribute to describe an externally visible AliasAttrs for parameters/return value. More... | |
| struct | llvm::cflaa::AliasSummary |
| AliasSummary is just a collection of ExternalRelation and ExternalAttribute. More... | |
| struct | llvm::cflaa::InstantiatedValue |
| This is the result of instantiating InterfaceValue at a particular callsite. More... | |
| struct | llvm::cflaa::InstantiatedRelation |
| This is the result of instantiating ExternalRelation at a particular callsite. More... | |
| struct | llvm::cflaa::InstantiatedAttr |
| This is the result of instantiating ExternalAttribute at a particular callsite. More... | |
| struct | llvm::DenseMapInfo< cflaa::InstantiatedValue > |
Namespaces | |
| llvm | |
| This class represents lattice values for constants. | |
| llvm::cflaa | |
Typedefs | |
| typedef std::bitset< NumAliasAttrs > | llvm::cflaa::AliasAttrs |
| These are attributes that an alias analysis can use to mark certain special properties of a given pointer. More... | |
Functions | |
| AliasAttrs | llvm::cflaa::getAttrNone () |
| Attr represent whether the said pointer comes from an unknown source (such as opaque memory or an integer cast). More... | |
| AliasAttrs | llvm::cflaa::getAttrUnknown () |
| AttrUnknown represent whether the said pointer comes from a source not known to alias analyses (such as opaque memory or an integer cast). More... | |
| bool | llvm::cflaa::hasUnknownAttr (AliasAttrs Attr) |
| AliasAttrs | llvm::cflaa::getAttrCaller () |
| AttrCaller represent whether the said pointer comes from a source not known to the current function but known to the caller. More... | |
| bool | llvm::cflaa::hasCallerAttr (AliasAttrs Attr) |
| bool | llvm::cflaa::hasUnknownOrCallerAttr (AliasAttrs Attr) |
| AliasAttrs | llvm::cflaa::getAttrEscaped () |
| AttrEscaped represent whether the said pointer comes from a known source but escapes to the unknown world (e.g. More... | |
| bool | llvm::cflaa::hasEscapedAttr (AliasAttrs Attr) |
| AliasAttrs | llvm::cflaa::getGlobalOrArgAttrFromValue (const Value &) |
| AttrGlobal represent whether the said pointer is a global value. More... | |
| bool | llvm::cflaa::isGlobalOrArgAttr (AliasAttrs Attr) |
| AliasAttrs | llvm::cflaa::getExternallyVisibleAttrs (AliasAttrs) |
| Given an AliasAttrs, return a new AliasAttrs that only contains attributes meaningful to the caller. More... | |
| bool | llvm::cflaa::operator== (InterfaceValue LHS, InterfaceValue RHS) |
| bool | llvm::cflaa::operator!= (InterfaceValue LHS, InterfaceValue RHS) |
| bool | llvm::cflaa::operator< (InterfaceValue LHS, InterfaceValue RHS) |
| bool | llvm::cflaa::operator> (InterfaceValue LHS, InterfaceValue RHS) |
| bool | llvm::cflaa::operator<= (InterfaceValue LHS, InterfaceValue RHS) |
| bool | llvm::cflaa::operator>= (InterfaceValue LHS, InterfaceValue RHS) |
| int64_t | llvm::cflaa::addOffset (int64_t LHS, int64_t RHS) |
| bool | llvm::cflaa::operator== (ExternalRelation LHS, ExternalRelation RHS) |
| bool | llvm::cflaa::operator!= (ExternalRelation LHS, ExternalRelation RHS) |
| bool | llvm::cflaa::operator< (ExternalRelation LHS, ExternalRelation RHS) |
| bool | llvm::cflaa::operator> (ExternalRelation LHS, ExternalRelation RHS) |
| bool | llvm::cflaa::operator<= (ExternalRelation LHS, ExternalRelation RHS) |
| bool | llvm::cflaa::operator>= (ExternalRelation LHS, ExternalRelation RHS) |
| Optional< InstantiatedValue > | llvm::cflaa::instantiateInterfaceValue (InterfaceValue IValue, CallSite CS) |
| bool | llvm::cflaa::operator== (InstantiatedValue LHS, InstantiatedValue RHS) |
| bool | llvm::cflaa::operator!= (InstantiatedValue LHS, InstantiatedValue RHS) |
| bool | llvm::cflaa::operator< (InstantiatedValue LHS, InstantiatedValue RHS) |
| bool | llvm::cflaa::operator> (InstantiatedValue LHS, InstantiatedValue RHS) |
| bool | llvm::cflaa::operator<= (InstantiatedValue LHS, InstantiatedValue RHS) |
| bool | llvm::cflaa::operator>= (InstantiatedValue LHS, InstantiatedValue RHS) |
| Optional< InstantiatedRelation > | llvm::cflaa::instantiateExternalRelation (ExternalRelation ERelation, CallSite CS) |
| Optional< InstantiatedAttr > | llvm::cflaa::instantiateExternalAttribute (ExternalAttribute EAttr, CallSite CS) |
Variables | |
| static const unsigned | llvm::cflaa::NumAliasAttrs = 32 |
| The number of attributes that AliasAttr should contain. More... | |
| static const unsigned | llvm::cflaa::MaxSupportedArgsInSummary = 50 |
| The maximum number of arguments we can put into a summary. More... | |
| static const int64_t | llvm::cflaa::UnknownOffset = INT64_MAX |
Detailed Description
This file defines various utility types and functions useful to summary-based alias analysis.
Summary-based analysis, also known as bottom-up analysis, is a style of interprocedrual static analysis that tries to analyze the callees before the callers get analyzed. The key idea of summary-based analysis is to first process each function independently, outline its behavior in a condensed summary, and then instantiate the summary at the callsite when the said function is called elsewhere. This is often in contrast to another style called top-down analysis, in which callers are always analyzed first before the callees.
In a summary-based analysis, functions must be examined independently and out-of-context. We have no information on the state of the memory, the arguments, the global values, and anything else external to the function. To carry out the analysis conservative assumptions have to be made about those external states. In exchange for the potential loss of precision, the summary we obtain this way is highly reusable, which makes the analysis easier to scale to large programs even if carried out context-sensitively.
Currently, all CFL-based alias analyses adopt the summary-based approach and therefore heavily rely on this header.
Definition in file AliasAnalysisSummary.h.
