llvm::GlobalStatus Struct Reference

As we analyze each global or thread-local variable, keep track of some information about it. More...

#include "llvm/Transforms/Utils/GlobalStatus.h"

Public Types
enum	StoredType { NotStored , InitializerStored , StoredOnce , Stored }
	Keep track of what stores to the global look like. More...

Public Member Functions
Value *	getStoredOnceValue () const
	If only one value (besides the initializer constant) is ever stored to this global return the stored value.
	GlobalStatus ()

Static Public Member Functions
static bool	analyzeGlobal (const Value *V, GlobalStatus &GS)
	Look at all uses of the global and fill in the GlobalStatus structure.

Public Attributes
bool	IsCompared = false
	True if the global's address is used in a comparison.
bool	IsLoaded = false
	True if the global is ever loaded.
unsigned	NumStores = 0
	Number of stores to the global.
enum llvm::GlobalStatus::StoredType	StoredType = NotStored
const StoreInst *	StoredOnceStore = nullptr
	If only one value (besides the initializer constant) is ever stored to this global, keep track of what value it is via the store instruction.
const Function *	AccessingFunction = nullptr
	These start out null/false.
bool	HasMultipleAccessingFunctions = false
AtomicOrdering	Ordering = AtomicOrdering::NotAtomic
	Set to the strongest atomic ordering requirement.

Detailed Description

As we analyze each global or thread-local variable, keep track of some information about it.

If we find out that the address of the global is taken, none of this info will be accurate.

Definition at line 30 of file GlobalStatus.h.

Member Enumeration Documentation

StoredType

enum llvm::GlobalStatus::StoredType

Keep track of what stores to the global look like.

Enumerator
NotStored	There is no store to this global. It can thus be marked constant.
InitializerStored	This global is stored to, but the only thing stored is the constant it was initialized with. This is only tracked for scalar globals.
StoredOnce	This global is stored to, but only its initializer and one other value is ever stored to it. If this global isStoredOnce, we track the value stored to it via StoredOnceStore below. This is only tracked for scalar globals.
Stored	This global is stored to by multiple values or something else that we cannot track.

Definition at line 42 of file GlobalStatus.h.

Constructor & Destructor Documentation

GlobalStatus()

GlobalStatus::GlobalStatus ( )

default

Member Function Documentation

analyzeGlobal()

bool GlobalStatus::analyzeGlobal ( const Value *  V, GlobalStatus &  GS  )

static

Look at all uses of the global and fill in the GlobalStatus structure.

If the global has its address taken, return true to indicate we can't do anything with it.

Definition at line 196 of file GlobalStatus.cpp.

References analyzeGlobalAux().

Referenced by processGlobal().

getStoredOnceValue()

Value * llvm::GlobalStatus::getStoredOnceValue ( ) const

inline

If only one value (besides the initializer constant) is ever stored to this global return the stored value.

Definition at line 67 of file GlobalStatus.h.

References llvm::User::getOperand(), StoredOnce, and StoredOnceStore.

Member Data Documentation

AccessingFunction

const Function* llvm::GlobalStatus::AccessingFunction = nullptr

These start out null/false.

When the first accessing function is noticed, it is recorded. When a second different accessing function is noticed, HasMultipleAccessingFunctions is set to true.

Definition at line 76 of file GlobalStatus.h.

HasMultipleAccessingFunctions

bool llvm::GlobalStatus::HasMultipleAccessingFunctions = false

Definition at line 77 of file GlobalStatus.h.

IsCompared

bool llvm::GlobalStatus::IsCompared = false

True if the global's address is used in a comparison.

Definition at line 32 of file GlobalStatus.h.

IsLoaded

bool llvm::GlobalStatus::IsLoaded = false

True if the global is ever loaded.

If the global isn't ever loaded it can be deleted.

Definition at line 36 of file GlobalStatus.h.

NumStores

unsigned llvm::GlobalStatus::NumStores = 0

Number of stores to the global.

Definition at line 39 of file GlobalStatus.h.

Ordering

AtomicOrdering llvm::GlobalStatus::Ordering = AtomicOrdering::NotAtomic

Set to the strongest atomic ordering requirement.

Definition at line 80 of file GlobalStatus.h.

StoredOnceStore

const StoreInst* llvm::GlobalStatus::StoredOnceStore = nullptr

If only one value (besides the initializer constant) is ever stored to this global, keep track of what value it is via the store instruction.

Definition at line 63 of file GlobalStatus.h.

Referenced by getStoredOnceValue().

StoredType

enum llvm::GlobalStatus::StoredType llvm::GlobalStatus::StoredType = NotStored

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The documentation for this struct was generated from the following files:

• include/llvm/Transforms/Utils/GlobalStatus.h
• lib/Transforms/Utils/GlobalStatus.cpp