AArch64PromoteConstant.cpp File Reference

#include "AArch64.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <utility>

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "aarch64-promote-const"

Functions
	STATISTIC (NumPromoted, "Number of promoted constants")
	STATISTIC (NumPromotedUses, "Number of promoted constants uses")
	INITIALIZE_PASS_BEGIN (AArch64PromoteConstant, "aarch64-promote-const", "AArch64 Promote Constant Pass", false, false) INITIALIZE_PASS_END(AArch64PromoteConstant
static bool	isConstantUsingVectorTy (const Type *CstTy)
	Check if the given type uses a vector type.
static bool	containsOnlyConstantData (const Constant *C)
static bool	shouldConvertUse (const Constant *Cst, const Instruction *Instr, unsigned OpIdx)
	Check if the given use (Instruction + OpIdx) of Cst should be converted into a load of a global variable initialized with Cst.
static bool	shouldConvertImpl (const Constant *Cst)
	Check if the given Cst should be converted into a load of a global variable initialized with Cst.
static bool	shouldConvert (Constant &C, AArch64PromoteConstant::PromotionCacheTy &PromotionCache)
static void	ensurePromotedGV (Function &F, Constant &C, AArch64PromoteConstant::PromotedConstant &PC)

Variables
static cl::opt< bool >	Stress ("aarch64-stress-promote-const", cl::Hidden, cl::desc("Promote all vector constants"))
aarch64 promote	const
aarch64 promote AArch64 Promote Constant	Pass
aarch64 promote AArch64 Promote Constant	false

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "aarch64-promote-const"

Definition at line 53 of file AArch64PromoteConstant.cpp.

Function Documentation

containsOnlyConstantData()

static bool containsOnlyConstantData ( const Constant *  C )

static

Definition at line 255 of file AArch64PromoteConstant.cpp.

References llvm::all_of(), and llvm::CallingConv::C.

ensurePromotedGV()

static void ensurePromotedGV ( Function &  F, Constant &  C, AArch64PromoteConstant::PromotedConstant &  PC  )

static

Definition at line 483 of file AArch64PromoteConstant.cpp.

References assert(), llvm::CallingConv::C, llvm::dbgs(), F, llvm::GlobalValue::InternalLinkage, and LLVM_DEBUG.

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	AArch64PromoteConstant	,
		"aarch64-promote-const"	,
		"AArch64 Promote Constant Pass"	,
		false	,
		false
	)

isConstantUsingVectorTy()

static bool isConstantUsingVectorTy ( const Type *  CstTy )

static

Check if the given type uses a vector type.

Definition at line 240 of file AArch64PromoteConstant.cpp.

References llvm::Type::getArrayElementType(), llvm::Type::getStructElementType(), llvm::Type::getStructNumElements(), llvm::Type::isArrayTy(), isConstantUsingVectorTy(), llvm::Type::isStructTy(), and llvm::Type::isVectorTy().

Referenced by isConstantUsingVectorTy(), and shouldConvertImpl().

shouldConvert()

static bool shouldConvert ( Constant &  C, AArch64PromoteConstant::PromotionCacheTy &  PromotionCache  )

static

Definition at line 362 of file AArch64PromoteConstant.cpp.

References llvm::CallingConv::C, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::insert(), and shouldConvertImpl().

shouldConvertImpl()

static bool shouldConvertImpl ( const Constant *  Cst )

static

Check if the given Cst should be converted into a load of a global variable initialized with Cst.

A constant should be converted if it is likely that the materialization of the constant will be tricky. Thus, we give up on zero or undef values.

Todo:

Currently, accept only vector related types. Also we give up on all simple vector type to keep the existing behavior. Otherwise, we should push here all the check of the lowering of BUILD_VECTOR. By giving up, we lose the potential benefit of merging constant via global merge and the fact that the same constant is stored only once with this method (versus, as many function that uses the constant for the regular approach, even for float). Again, the simplest solution would be to promote every constant and rematerialize them when they are actually cheap to create.

Definition at line 338 of file AArch64PromoteConstant.cpp.

References llvm::Value::getType(), isConstantUsingVectorTy(), llvm::Type::isVectorTy(), llvm::Constant::isZeroValue(), and Stress.

Referenced by shouldConvert().

shouldConvertUse()

static bool shouldConvertUse ( const Constant *  Cst, const Instruction *  Instr, unsigned  OpIdx  )

static

Check if the given use (Instruction + OpIdx) of Cst should be converted into a load of a global variable initialized with Cst.

A use should be converted if it is legal to do so. For instance, it is not legal to turn the mask operand of a shuffle vector into a load of a global variable.

Definition at line 272 of file AArch64PromoteConstant.cpp.

References llvm::CallBase::isInlineAsm().

STATISTIC() [1/2]

STATISTIC	(	NumPromoted	,
		"Number of promoted constants"
	)

STATISTIC() [2/2]

STATISTIC	(	NumPromotedUses	,
		"Number of promoted constants uses"
	)

Variable Documentation

const

aarch64 promote const

Definition at line 232 of file AArch64PromoteConstant.cpp.

false

aarch64 promote AArch64 Promote Constant false

Definition at line 233 of file AArch64PromoteConstant.cpp.

Pass

aarch64 promote AArch64 Promote Constant Pass

Definition at line 233 of file AArch64PromoteConstant.cpp.

Stress

cl::opt< bool > Stress("aarch64-stress-promote-const", cl::Hidden, cl::desc("Promote all vector constants")) ( "aarch64-stress-promote-const"  , cl::Hidden  , cl::desc("Promote all vector constants")    )

static

Referenced by shouldConvertImpl().