Analysis.cpp File Reference

#include "llvm/CodeGen/Analysis.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/TargetMachine.h"

Go to the source code of this file.

Functions
static bool	isNoopBitcast (Type *T1, Type *T2, const TargetLoweringBase &TLI)
static const Value *	getNoopInput (const Value *V, SmallVectorImpl< unsigned > &ValLoc, unsigned &DataBits, const TargetLoweringBase &TLI, const DataLayout &DL)
	Look through operations that will be free to find the earliest source of this value.
static bool	slotOnlyDiscardsData (const Value *RetVal, const Value *CallVal, SmallVectorImpl< unsigned > &RetIndices, SmallVectorImpl< unsigned > &CallIndices, bool AllowDifferingSizes, const TargetLoweringBase &TLI, const DataLayout &DL)
	Return true if this scalar return value only has bits discarded on its path from the "tail call" to the "ret".
static bool	indexReallyValid (Type *T, unsigned Idx)
	For an aggregate type, determine whether a given index is within bounds or not.
static bool	advanceToNextLeafType (SmallVectorImpl< Type * > &SubTypes, SmallVectorImpl< unsigned > &Path)
	Move the given iterators to the next leaf type in depth first traversal.
static bool	firstRealType (Type *Next, SmallVectorImpl< Type * > &SubTypes, SmallVectorImpl< unsigned > &Path)
	Find the first non-empty, scalar-like type in Next and setup the iterator components.
static bool	nextRealType (SmallVectorImpl< Type * > &SubTypes, SmallVectorImpl< unsigned > &Path)
	Set the iterator data-structures to the next non-empty, non-aggregate subtype.
static void	collectEHScopeMembers (DenseMap< const MachineBasicBlock *, int > &EHScopeMembership, int EHScope, const MachineBasicBlock *MBB)

Function Documentation

advanceToNextLeafType()

static bool advanceToNextLeafType ( SmallVectorImpl< Type * > &  SubTypes, SmallVectorImpl< unsigned > &  Path  )

static

Move the given iterators to the next leaf type in depth first traversal.

Performs a depth-first traversal of the type as specified by its arguments, stopping at the next leaf node (which may be a legitimate scalar type or an empty struct or array).

Parameters

SubTypes	List of the partial components making up the type from outermost to innermost non-empty aggregate. The element currently represented is SubTypes.back()->getTypeAtIndex(Path.back() - 1).
Path	Set of extractvalue indices leading from the outermost type (SubTypes[0]) to the leaf node currently represented.

Returns

true if a new type was found, false otherwise. Calling this function again on a finished iterator will repeatedly return false. SubTypes.back()->getTypeAtIndex(Path.back()) is either an empty aggregate or a non-aggregate

Definition at line 445 of file Analysis.cpp.

References llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::ExtractValueInst::getIndexedType(), indexReallyValid(), llvm::Type::isAggregateType(), llvm::SmallVectorTemplateBase< T, bool >::pop_back(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by firstRealType(), and nextRealType().

collectEHScopeMembers()

static void collectEHScopeMembers ( DenseMap< const MachineBasicBlock *, int > &  EHScopeMembership, int  EHScope, const MachineBasicBlock *  MBB  )

static

Definition at line 723 of file Analysis.cpp.

References llvm::append_range(), assert(), llvm::SmallVectorBase< Size_T >::empty(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::insert(), llvm::MachineBasicBlock::isEHPad(), llvm::MachineBasicBlock::isEHScopeReturnBlock(), MBB, P, llvm::SmallVectorImpl< T >::pop_back_val(), and llvm::MachineBasicBlock::successors().

Referenced by llvm::getEHScopeMembership().

firstRealType()

static bool firstRealType ( Type *  Next, SmallVectorImpl< Type * > &  SubTypes, SmallVectorImpl< unsigned > &  Path  )

static

Find the first non-empty, scalar-like type in Next and setup the iterator components.

Assuming Next is an aggregate of some kind, this function will traverse the tree from left to right (i.e. depth-first) looking for the first non-aggregate type which will play a role in function return.

For example, if Next was {[0 x i64], {{}, i32, {}}, i32} then we would setup Path as [1, 1] and SubTypes as [Next, {{}, i32, {}}] to represent the first i32 in that type.

Definition at line 486 of file Analysis.cpp.

References advanceToNextLeafType(), llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::ExtractValueInst::getIndexedType(), llvm::Type::isAggregateType(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by llvm::returnTypeIsEligibleForTailCall().

getNoopInput()

static const Value * getNoopInput ( const Value *  V, SmallVectorImpl< unsigned > &  ValLoc, unsigned &  DataBits, const TargetLoweringBase &  TLI, const DataLayout &  DL  )

static

Look through operations that will be free to find the earliest source of this value.

Parameters

ValLoc	If V has aggregate type, we will be interested in a particular scalar component. This records its address; the reverse of this list gives a sequence of indices appropriate for an extractvalue to locate the important value. This value is updated during the function and on exit will indicate similar information for the Value returned.
DataBits	If this function looks through truncate instructions, this will record the smallest size attained.

Definition at line 295 of file Analysis.cpp.

References llvm::TargetLoweringBase::allowTruncateForTailCall(), llvm::SmallVectorImpl< T >::append(), llvm::ArrayRef< T >::begin(), DL, llvm::ArrayRef< T >::end(), llvm::Value::getType(), I, isNoopBitcast(), llvm::SmallVectorTemplateCommon< T, typename >::rbegin(), llvm::ArrayRef< T >::rbegin(), llvm::ArrayRef< T >::rend(), llvm::SmallVectorImpl< T >::resize(), llvm::ArrayRef< T >::size(), and llvm::SmallVectorBase< Size_T >::size().

Referenced by slotOnlyDiscardsData().

indexReallyValid()

static bool indexReallyValid ( Type *  T, unsigned  Idx  )

static

For an aggregate type, determine whether a given index is within bounds or not.

Definition at line 421 of file Analysis.cpp.

References Idx.

Referenced by advanceToNextLeafType().

isNoopBitcast()

static bool isNoopBitcast ( Type *  T1, Type *  T2, const TargetLoweringBase &  TLI  )

static

Definition at line 277 of file Analysis.cpp.

References llvm::EVT::getEVT(), llvm::Type::isPointerTy(), llvm::TargetLoweringBase::isTypeLegal(), and T1.

Referenced by getNoopInput().

nextRealType()

static bool nextRealType ( SmallVectorImpl< Type * > &  SubTypes, SmallVectorImpl< unsigned > &  Path  )

static

Set the iterator data-structures to the next non-empty, non-aggregate subtype.

Definition at line 515 of file Analysis.cpp.

References advanceToNextLeafType(), assert(), llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::ExtractValueInst::getIndexedType(), and llvm::Type::isAggregateType().

Referenced by llvm::returnTypeIsEligibleForTailCall().

slotOnlyDiscardsData()

static bool slotOnlyDiscardsData ( const Value *  RetVal, const Value *  CallVal, SmallVectorImpl< unsigned > &  RetIndices, SmallVectorImpl< unsigned > &  CallIndices, bool  AllowDifferingSizes, const TargetLoweringBase &  TLI, const DataLayout &  DL  )

static

Return true if this scalar return value only has bits discarded on its path from the "tail call" to the "ret".

This includes the obvious noop instructions handled by getNoopInput above as well as free truncations (or extensions prior to the call).

Definition at line 377 of file Analysis.cpp.

References DL, and getNoopInput().

Referenced by llvm::returnTypeIsEligibleForTailCall().