LLVM  3.7.0
Macros | Functions | Variables
LoopUnswitch.cpp File Reference
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CodeMetrics.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/Local.h"
#include <algorithm>
#include <map>
#include <set>
Include dependency graph for LoopUnswitch.cpp:

Go to the source code of this file.

Macros

#define DEBUG_TYPE   "loop-unswitch"
 

Functions

 STATISTIC (NumBranches,"Number of branches unswitched")
 
 STATISTIC (NumSwitches,"Number of switches unswitched")
 
 STATISTIC (NumSelects,"Number of selects unswitched")
 
 STATISTIC (NumTrivial,"Number of unswitches that are trivial")
 
 STATISTIC (NumSimplify,"Number of simplifications of unswitched code")
 
 STATISTIC (TotalInsts,"Total number of instructions analyzed")
 
 INITIALIZE_PASS_BEGIN (LoopUnswitch,"loop-unswitch","Unswitch loops", false, false) INITIALIZE_PASS_END(LoopUnswitch
 
static ValueFindLIVLoopCondition (Value *Cond, Loop *L, bool &Changed)
 FindLIVLoopCondition - Cond is a condition that occurs in L. More...
 
static bool isTrivialLoopExitBlockHelper (Loop *L, BasicBlock *BB, BasicBlock *&ExitBB, std::set< BasicBlock * > &Visited)
 isTrivialLoopExitBlock - Check to see if all paths from BB exit the loop with no side effects (including infinite loops). More...
 
static BasicBlockisTrivialLoopExitBlock (Loop *L, BasicBlock *BB)
 isTrivialLoopExitBlock - Return true if the specified block unconditionally leads to an exit from the specified loop, and has no side-effects in the process. More...
 
static LoopCloneLoop (Loop *L, Loop *PL, ValueToValueMapTy &VM, LoopInfo *LI, LPPassManager *LPM)
 CloneLoop - Recursively clone the specified loop and all of its children, mapping the blocks with the specified map. More...
 
static void copyMetadata (Instruction *DstInst, const Instruction *SrcInst, bool Swapped)
 
static void RemoveFromWorklist (Instruction *I, std::vector< Instruction * > &Worklist)
 RemoveFromWorklist - Remove all instances of I from the worklist vector specified. More...
 
static void ReplaceUsesOfWith (Instruction *I, Value *V, std::vector< Instruction * > &Worklist, Loop *L, LPPassManager *LPM)
 ReplaceUsesOfWith - When we find that I really equals V, remove I from the program, replacing all uses with V and update the worklist. More...
 

Variables

static cl::opt< unsignedThreshold ("loop-unswitch-threshold", cl::desc("Max loop size to unswitch"), cl::init(100), cl::Hidden)
 
loop unswitch
 
loop Unswitch loops
 
loop Unswitch false
 

Macro Definition Documentation

#define DEBUG_TYPE   "loop-unswitch"

Definition at line 58 of file LoopUnswitch.cpp.

Function Documentation

static Loop* CloneLoop ( Loop L,
Loop PL,
ValueToValueMapTy VM,
LoopInfo LI,
LPPassManager LPM 
)
static
static void copyMetadata ( Instruction DstInst,
const Instruction SrcInst,
bool  Swapped 
)
static
static Value* FindLIVLoopCondition ( Value Cond,
Loop L,
bool Changed 
)
static

FindLIVLoopCondition - Cond is a condition that occurs in L.

If it is invariant in the loop, or has an invariant piece, return the invariant. Otherwise, return null.

Definition at line 373 of file LoopUnswitch.cpp.

References llvm::APIntOps::And(), llvm::Value::getType(), llvm::Type::isVectorTy(), llvm::Loop::makeLoopInvariant(), and llvm::APIntOps::Or().

INITIALIZE_PASS_BEGIN ( LoopUnswitch  ,
"loop-unswitch ,
"Unswitch loops ,
false  ,
false   
)
static BasicBlock* isTrivialLoopExitBlock ( Loop L,
BasicBlock BB 
)
static

isTrivialLoopExitBlock - Return true if the specified block unconditionally leads to an exit from the specified loop, and has no side-effects in the process.

If so, return the block that is exited to, otherwise return null.

Definition at line 572 of file LoopUnswitch.cpp.

References llvm::LoopBase< N, M >::getHeader(), and isTrivialLoopExitBlockHelper().

static bool isTrivialLoopExitBlockHelper ( Loop L,
BasicBlock BB,
BasicBlock *&  ExitBB,
std::set< BasicBlock * > &  Visited 
)
static

isTrivialLoopExitBlock - Check to see if all paths from BB exit the loop with no side effects (including infinite loops).

If true, we return true and set ExitBB to the block we exit through.

Definition at line 537 of file LoopUnswitch.cpp.

References llvm::BasicBlock::begin(), llvm::LoopBase< N, M >::contains(), llvm::BasicBlock::end(), I, llvm::succ_begin(), and llvm::succ_end().

Referenced by isTrivialLoopExitBlock().

static void RemoveFromWorklist ( Instruction I,
std::vector< Instruction * > &  Worklist 
)
static

RemoveFromWorklist - Remove all instances of I from the worklist vector specified.

Definition at line 999 of file LoopUnswitch.cpp.

References I, and llvm::sys::fs::remove().

Referenced by ReplaceUsesOfWith().

static void ReplaceUsesOfWith ( Instruction I,
Value V,
std::vector< Instruction * > &  Worklist,
Loop L,
LPPassManager LPM 
)
static

ReplaceUsesOfWith - When we find that I really equals V, remove I from the program, replacing all uses with V and update the worklist.

Definition at line 1008 of file LoopUnswitch.cpp.

References llvm::dbgs(), DEBUG, llvm::LPPassManager::deleteSimpleAnalysisValue(), llvm::Instruction::eraseFromParent(), llvm::User::getNumOperands(), llvm::User::getOperand(), RemoveFromWorklist(), llvm::Value::replaceAllUsesWith(), and llvm::Value::users().

STATISTIC ( NumBranches  ,
"Number of branches unswitched"   
)
STATISTIC ( NumSwitches  ,
"Number of switches unswitched"   
)
STATISTIC ( NumSelects  ,
"Number of selects unswitched"   
)
STATISTIC ( NumTrivial  ,
"Number of unswitches that are trivial"   
)
STATISTIC ( NumSimplify  ,
"Number of simplifications of unswitched code"   
)
STATISTIC ( TotalInsts  ,
"Total number of instructions analyzed"   
)

Variable Documentation

loop Unswitch false

Definition at line 363 of file LoopUnswitch.cpp.

loop Unswitch loops

Definition at line 363 of file LoopUnswitch.cpp.

cl::opt<unsigned> Threshold("loop-unswitch-threshold", cl::desc("Max loop size to unswitch"), cl::init(100), cl::Hidden)
static
loop unswitch

Definition at line 363 of file LoopUnswitch.cpp.