ArgumentPromotion.cpp File Reference

#include "llvm/Transforms/IPO/ArgumentPromotion.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/CGSCCPassManager.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Analysis/CallGraphSCCPass.h"
#include "llvm/Analysis/LazyCallGraph.h"
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/NoFolder.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Use.h"
#include "llvm/IR/User.h"
#include "llvm/IR/Value.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/IPO.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <functional>
#include <iterator>
#include <map>
#include <set>
#include <utility>
#include <vector>

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "argpromotion"

Typedefs
using	IndicesVector = std::vector< uint64_t >
	A vector used to hold the indices of a single GEP instruction. More...

Functions
	STATISTIC (NumArgumentsPromoted, "Number of pointer arguments promoted")
	STATISTIC (NumAggregatesPromoted, "Number of aggregate arguments promoted")
	STATISTIC (NumByValArgsPromoted, "Number of byval arguments promoted")
	STATISTIC (NumArgumentsDead, "Number of dead pointer args eliminated")
static Function *	doPromotion (Function *F, SmallPtrSetImpl< Argument * > &ArgsToPromote, SmallPtrSetImpl< Argument * > &ByValArgsToTransform, Optional< function_ref< void(CallBase &OldCS, CallBase &NewCS)>> ReplaceCallSite)
	DoPromotion - This method actually performs the promotion of the specified arguments, and returns the new function. More...
static bool	allCallersPassValidPointerForArgument (Argument *Arg, Type *Ty)
	Return true if we can prove that all callees pass in a valid pointer for the specified function argument. More...
static bool	isPrefix (const IndicesVector &Prefix, const IndicesVector &Longer)
	Returns true if Prefix is a prefix of longer. More...
static bool	prefixIn (const IndicesVector &Indices, std::set< IndicesVector > &Set)
	Checks if Indices, or a prefix of Indices, is in Set. More...
static void	markIndicesSafe (const IndicesVector &ToMark, std::set< IndicesVector > &Safe)
	Mark the given indices (ToMark) as safe in the given set of indices (Safe). More...
static bool	isSafeToPromoteArgument (Argument *Arg, Type *ByValTy, AAResults &AAR, unsigned MaxElements)
	isSafeToPromoteArgument - As you might guess from the name of this method, it checks to see if it is both safe and useful to promote the argument. More...
static bool	canPaddingBeAccessed (Argument *arg)
	Checks if the padding bytes of an argument could be accessed. More...
static Function *	promoteArguments (Function *F, function_ref< AAResults &(Function &F)> AARGetter, unsigned MaxElements, Optional< function_ref< void(CallBase &OldCS, CallBase &NewCS)>> ReplaceCallSite, const TargetTransformInfo &TTI)
	PromoteArguments - This method checks the specified function to see if there are any promotable arguments and if it is safe to promote the function (for example, all callers are direct). More...
	INITIALIZE_PASS_BEGIN (ArgPromotion, "argpromotion", "Promote 'by reference' arguments to scalars", false, false) INITIALIZE_PASS_END(ArgPromotion

Variables
	argpromotion
Promote by reference arguments to	scalars
Promote by reference arguments to	false

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "argpromotion"

Definition at line 90 of file ArgumentPromotion.cpp.

Typedef Documentation

IndicesVector

using IndicesVector = std::vector<uint64_t>

A vector used to hold the indices of a single GEP instruction.

Definition at line 98 of file ArgumentPromotion.cpp.

Function Documentation

allCallersPassValidPointerForArgument()

static bool allCallersPassValidPointerForArgument ( Argument *  Arg, Type *  Ty  )

static

Return true if we can prove that all callees pass in a valid pointer for the specified function argument.

Definition at line 479 of file ArgumentPromotion.cpp.

References Arg, Callee, DL, llvm::CallBase::getArgOperand(), and llvm::isDereferenceablePointer().

Referenced by isSafeToPromoteArgument().

canPaddingBeAccessed()

static bool canPaddingBeAccessed ( Argument *  arg )

static

Checks if the padding bytes of an argument could be accessed.

Definition at line 802 of file ArgumentPromotion.cpp.

References llvm::append_range(), assert(), llvm::SmallPtrSetImpl< PtrType >::count(), llvm::Argument::hasByValAttr(), llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SPII::Store, and llvm::Value::users().

Referenced by promoteArguments().

doPromotion()

static Function* doPromotion ( Function *  F, SmallPtrSetImpl< Argument * > &  ArgsToPromote, SmallPtrSetImpl< Argument * > &  ByValArgsToTransform, Optional< function_ref< void(CallBase &OldCS, CallBase &NewCS)>>  ReplaceCallSite  )

static

DoPromotion - This method actually performs the promotion of the specified arguments, and returns the new function.

At this point, we know that it's safe to do so.

Definition at line 104 of file ArgumentPromotion.cpp.

References llvm::append_range(), llvm::Function::arg_begin(), llvm::CallBase::arg_begin(), llvm::CallBase::arg_end(), llvm::AMDGPU::HSAMD::Kernel::Key::Args, assert(), llvm::Function::begin(), llvm::SmallVectorImpl< T >::clear(), llvm::commonAlignment(), llvm::Function::copyAttributesFrom(), llvm::GlobalObject::copyMetadata(), llvm::Instruction::copyMetadata(), llvm::SmallPtrSetImpl< PtrType >::count(), llvm::Function::Create(), llvm::GetElementPtrInst::Create(), llvm::CallInst::Create(), llvm::InvokeInst::Create(), llvm::IRBuilderBase::CreateAlignedLoad(), llvm::IRBuilderBase::CreateGEP(), llvm::IRBuilderBase::CreateLoad(), llvm::dbgs(), DL, llvm::numbers::e, E, llvm::StructType::elements(), llvm::Instruction::eraseFromParent(), F, llvm::formatv(), GEP, llvm::ConstantInt::get(), llvm::FunctionType::get(), llvm::AttributeList::get(), llvm::UndefValue::get(), llvm::Instruction::getAAMetadata(), llvm::LoadInst::getAlign(), llvm::CallBase::getAttributes(), llvm::Function::getBasicBlockList(), llvm::CallBase::getCalledFunction(), llvm::CallBase::getCallingConv(), llvm::StructLayout::getElementOffset(), llvm::StructType::getElementType(), llvm::AttributeList::getFnAttrs(), llvm::GetElementPtrInst::getIndexedType(), llvm::Type::getInt32Ty(), llvm::Type::getInt64Ty(), llvm::Value::getName(), llvm::StructType::getNumElements(), llvm::User::getNumOperands(), llvm::CallBase::getOperandBundlesAsDefs(), llvm::AttributeList::getParamAttrs(), llvm::AttributeList::getRetAttrs(), llvm::FunctionType::getReturnType(), llvm::Value::getType(), llvm::GetElementPtrInst::getTypeAtIndex(), i, I, llvm::ARM_PROC::IE, llvm::SmallVectorImpl< T >::insert(), llvm::Type::isStructTy(), llvm::FunctionType::isVarArg(), LLVM_DEBUG, llvm::make_early_inc_range(), llvm::make_range(), llvm::make_scope_exit(), llvm::User::op_begin(), llvm::User::op_end(), Operands, llvm::Value::replaceAllUsesWith(), llvm::Instruction::setAAMetadata(), llvm::LoadInst::setAlignment(), llvm::Function::setAttributes(), llvm::CallBase::setAttributes(), llvm::CallBase::setCallingConv(), llvm::Value::setName(), llvm::Value::takeName(), llvm::Value::use_empty(), and llvm::Instruction::user_back().

Referenced by promoteArguments().

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	ArgPromotion	,
		"argpromotion"	,
		"Promote 'by reference' arguments to scalars"	,
		false	,
		false
	)

isPrefix()

static bool isPrefix ( const IndicesVector &  Prefix, const IndicesVector &  Longer  )

static

Returns true if Prefix is a prefix of longer.

That means, Longer has a size that is greater than or equal to the size of prefix, and each of the elements in Prefix is the same as the corresponding elements in Longer.

This means it also returns true when Prefix and Longer are equal!

Definition at line 501 of file ArgumentPromotion.cpp.

References llvm::lltok::equal, and llvm::cl::Prefix.

Referenced by markIndicesSafe(), and prefixIn().

isSafeToPromoteArgument()

static bool isSafeToPromoteArgument ( Argument *  Arg, Type *  ByValTy, AAResults &  AAR, unsigned  MaxElements  )

static

isSafeToPromoteArgument - As you might guess from the name of this method, it checks to see if it is both safe and useful to promote the argument.

This method limits promotion of aggregates to only promote up to three elements of the aggregate in order to avoid exploding the number of arguments passed in.

Definition at line 563 of file ArgumentPromotion.cpp.

References allCallersPassValidPointerForArgument(), Arg, assert(), BB, llvm::AAResults::canBasicBlockModify(), llvm::AAResults::canInstructionRangeModRef(), llvm::dbgs(), GEP, llvm::MemoryLocation::get(), I, llvm::inverse_depth_first_ext(), LLVM_DEBUG, llvm::SPII::Load, markIndicesSafe(), llvm::Mod, move, Operands, P, llvm::predecessors(), and prefixIn().

Referenced by promoteArguments().

markIndicesSafe()

static void markIndicesSafe ( const IndicesVector &  ToMark, std::set< IndicesVector > &  Safe  )

static

Mark the given indices (ToMark) as safe in the given set of indices (Safe).

Marking safe usually means adding ToMark to Safe. However, if there is already a prefix of Indices in Safe, Indices are implicitely marked safe already. Furthermore, any indices that Indices is itself a prefix of, are removed from Safe (since they are implicitely safe because of Indices now).

Definition at line 527 of file ArgumentPromotion.cpp.

References isPrefix().

Referenced by isSafeToPromoteArgument().

prefixIn()

static bool prefixIn ( const IndicesVector &  Indices, std::set< IndicesVector > &  Set  )

static

Checks if Indices, or a prefix of Indices, is in Set.

Definition at line 508 of file ArgumentPromotion.cpp.

References isPrefix().

Referenced by isSafeToPromoteArgument().

promoteArguments()

static Function* promoteArguments ( Function *  F, function_ref< AAResults &(Function &F)>  AARGetter, unsigned  MaxElements, Optional< function_ref< void(CallBase &OldCS, CallBase &NewCS)>>  ReplaceCallSite, const TargetTransformInfo &  TTI  )

static

PromoteArguments - This method checks the specified function to see if there are any promotable arguments and if it is safe to promote the function (for example, all callers are direct).

If safe to promote some arguments, it calls the DoPromotion method.

Definition at line 857 of file ArgumentPromotion.cpp.

References llvm::CallBase::addParamAttr(), llvm::ArgumentPromotionPass::areFunctionArgsABICompatible(), BB, canPaddingBeAccessed(), llvm::dbgs(), DL, doPromotion(), llvm::SmallPtrSetImplBase::empty(), F, llvm::Instruction::getParent(), llvm::BasicBlock::getParent(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::is_contained(), llvm::CallBase::isCallee(), llvm::ArgumentPromotionPass::isDenselyPacked(), llvm::CallBase::isMustTailCall(), isSafeToPromoteArgument(), LLVM_DEBUG, and llvm::CallBase::removeParamAttr().

Referenced by llvm::ArgumentPromotionPass::run().

STATISTIC() [1/4]

STATISTIC	(	NumAggregatesPromoted	,
		"Number of aggregate arguments promoted"
	)

STATISTIC() [2/4]

STATISTIC	(	NumArgumentsDead	,
		"Number of dead pointer args eliminated"
	)

STATISTIC() [3/4]

STATISTIC	(	NumArgumentsPromoted	,
		"Number of pointer arguments promoted"
	)

STATISTIC() [4/4]

STATISTIC	(	NumByValArgsPromoted	,
		"Number of byval arguments promoted"
	)

Variable Documentation

argpromotion

argpromotion

Definition at line 1099 of file ArgumentPromotion.cpp.

false

Promote by reference arguments to false

Definition at line 1100 of file ArgumentPromotion.cpp.

scalars

Promote by reference arguments to scalars

Definition at line 1100 of file ArgumentPromotion.cpp.