summaryrefslogtreecommitdiffstats
path: root/contrib/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'contrib/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp')
-rw-r--r--contrib/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp106
1 files changed, 44 insertions, 62 deletions
diff --git a/contrib/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp b/contrib/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
index c4ebfd5..977c53a 100644
--- a/contrib/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/contrib/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -26,13 +26,11 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "loop-unswitch"
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/CodeMetrics.h"
-#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
@@ -40,6 +38,7 @@
#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/Support/CommandLine.h"
@@ -53,6 +52,8 @@
#include <set>
using namespace llvm;
+#define DEBUG_TYPE "loop-unswitch"
+
STATISTIC(NumBranches, "Number of branches unswitched");
STATISTIC(NumSwitches, "Number of switches unswitched");
STATISTIC(NumSelects , "Number of selects unswitched");
@@ -96,7 +97,7 @@ namespace {
public:
LUAnalysisCache() :
- CurLoopInstructions(0), CurrentLoopProperties(0),
+ CurLoopInstructions(nullptr), CurrentLoopProperties(nullptr),
MaxSize(Threshold)
{}
@@ -151,44 +152,35 @@ namespace {
static char ID; // Pass ID, replacement for typeid
explicit LoopUnswitch(bool Os = false) :
LoopPass(ID), OptimizeForSize(Os), redoLoop(false),
- currentLoop(0), DT(0), loopHeader(0),
- loopPreheader(0) {
+ currentLoop(nullptr), DT(nullptr), loopHeader(nullptr),
+ loopPreheader(nullptr) {
initializeLoopUnswitchPass(*PassRegistry::getPassRegistry());
}
- bool runOnLoop(Loop *L, LPPassManager &LPM);
+ bool runOnLoop(Loop *L, LPPassManager &LPM) override;
bool processCurrentLoop();
/// This transformation requires natural loop information & requires that
/// loop preheaders be inserted into the CFG.
///
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequiredID(LoopSimplifyID);
AU.addPreservedID(LoopSimplifyID);
AU.addRequired<LoopInfo>();
AU.addPreserved<LoopInfo>();
AU.addRequiredID(LCSSAID);
AU.addPreservedID(LCSSAID);
- AU.addPreserved<DominatorTree>();
+ AU.addPreserved<DominatorTreeWrapperPass>();
AU.addPreserved<ScalarEvolution>();
AU.addRequired<TargetTransformInfo>();
}
private:
- virtual void releaseMemory() {
+ void releaseMemory() override {
BranchesInfo.forgetLoop(currentLoop);
}
- /// RemoveLoopFromWorklist - If the specified loop is on the loop worklist,
- /// remove it.
- void RemoveLoopFromWorklist(Loop *L) {
- std::vector<Loop*>::iterator I = std::find(LoopProcessWorklist.begin(),
- LoopProcessWorklist.end(), L);
- if (I != LoopProcessWorklist.end())
- LoopProcessWorklist.erase(I);
- }
-
void initLoopData() {
loopHeader = currentLoop->getHeader();
loopPreheader = currentLoop->getLoopPreheader();
@@ -212,9 +204,8 @@ namespace {
Instruction *InsertPt);
void SimplifyCode(std::vector<Instruction*> &Worklist, Loop *L);
- void RemoveLoopFromHierarchy(Loop *L);
- bool IsTrivialUnswitchCondition(Value *Cond, Constant **Val = 0,
- BasicBlock **LoopExit = 0);
+ bool IsTrivialUnswitchCondition(Value *Cond, Constant **Val = nullptr,
+ BasicBlock **LoopExit = nullptr);
};
}
@@ -225,7 +216,7 @@ bool LUAnalysisCache::countLoop(const Loop *L, const TargetTransformInfo &TTI) {
LoopPropsMapIt PropsIt;
bool Inserted;
- llvm::tie(PropsIt, Inserted) =
+ std::tie(PropsIt, Inserted) =
LoopsProperties.insert(std::make_pair(L, LoopProperties()));
LoopProperties &Props = PropsIt->second;
@@ -283,8 +274,8 @@ void LUAnalysisCache::forgetLoop(const Loop *L) {
LoopsProperties.erase(LIt);
}
- CurrentLoopProperties = 0;
- CurLoopInstructions = 0;
+ CurrentLoopProperties = nullptr;
+ CurLoopInstructions = nullptr;
}
// Mark case value as unswitched.
@@ -355,10 +346,10 @@ static Value *FindLIVLoopCondition(Value *Cond, Loop *L, bool &Changed) {
// We can never unswitch on vector conditions.
if (Cond->getType()->isVectorTy())
- return 0;
+ return nullptr;
// Constants should be folded, not unswitched on!
- if (isa<Constant>(Cond)) return 0;
+ if (isa<Constant>(Cond)) return nullptr;
// TODO: Handle: br (VARIANT|INVARIANT).
@@ -378,13 +369,18 @@ static Value *FindLIVLoopCondition(Value *Cond, Loop *L, bool &Changed) {
return RHS;
}
- return 0;
+ return nullptr;
}
bool LoopUnswitch::runOnLoop(Loop *L, LPPassManager &LPM_Ref) {
+ if (skipOptnoneFunction(L))
+ return false;
+
LI = &getAnalysis<LoopInfo>();
LPM = &LPM_Ref;
- DT = getAnalysisIfAvailable<DominatorTree>();
+ DominatorTreeWrapperPass *DTWP =
+ getAnalysisIfAvailable<DominatorTreeWrapperPass>();
+ DT = DTWP ? &DTWP->getDomTree() : nullptr;
currentLoop = L;
Function *F = currentLoop->getHeader()->getParent();
bool Changed = false;
@@ -397,7 +393,7 @@ bool LoopUnswitch::runOnLoop(Loop *L, LPPassManager &LPM_Ref) {
if (Changed) {
// FIXME: Reconstruct dom info, because it is not preserved properly.
if (DT)
- DT->runOnFunction(*F);
+ DT->recalculate(*F);
}
return Changed;
}
@@ -456,7 +452,7 @@ bool LoopUnswitch::processCurrentLoop() {
// Find a value to unswitch on:
// FIXME: this should chose the most expensive case!
// FIXME: scan for a case with a non-critical edge?
- Constant *UnswitchVal = 0;
+ Constant *UnswitchVal = nullptr;
// Do not process same value again and again.
// At this point we have some cases already unswitched and
@@ -513,7 +509,7 @@ static bool isTrivialLoopExitBlockHelper(Loop *L, BasicBlock *BB,
if (!L->contains(BB)) {
// Otherwise, this is a loop exit, this is fine so long as this is the
// first exit.
- if (ExitBB != 0) return false;
+ if (ExitBB) return false;
ExitBB = BB;
return true;
}
@@ -540,10 +536,10 @@ static bool isTrivialLoopExitBlockHelper(Loop *L, BasicBlock *BB,
static BasicBlock *isTrivialLoopExitBlock(Loop *L, BasicBlock *BB) {
std::set<BasicBlock*> Visited;
Visited.insert(L->getHeader()); // Branches to header make infinite loops.
- BasicBlock *ExitBB = 0;
+ BasicBlock *ExitBB = nullptr;
if (isTrivialLoopExitBlockHelper(L, BB, ExitBB, Visited))
return ExitBB;
- return 0;
+ return nullptr;
}
/// IsTrivialUnswitchCondition - Check to see if this unswitch condition is
@@ -564,7 +560,7 @@ bool LoopUnswitch::IsTrivialUnswitchCondition(Value *Cond, Constant **Val,
TerminatorInst *HeaderTerm = Header->getTerminator();
LLVMContext &Context = Header->getContext();
- BasicBlock *LoopExitBB = 0;
+ BasicBlock *LoopExitBB = nullptr;
if (BranchInst *BI = dyn_cast<BranchInst>(HeaderTerm)) {
// If the header block doesn't end with a conditional branch on Cond, we
// can't handle it.
@@ -634,8 +630,8 @@ bool LoopUnswitch::IsTrivialUnswitchCondition(Value *Cond, Constant **Val,
/// unswitch the loop, reprocess the pieces, then return true.
bool LoopUnswitch::UnswitchIfProfitable(Value *LoopCond, Constant *Val) {
Function *F = loopHeader->getParent();
- Constant *CondVal = 0;
- BasicBlock *ExitBlock = 0;
+ Constant *CondVal = nullptr;
+ BasicBlock *ExitBlock = nullptr;
if (IsTrivialUnswitchCondition(LoopCond, &CondVal, &ExitBlock)) {
// If the condition is trivial, always unswitch. There is no code growth
@@ -934,9 +930,8 @@ static void ReplaceUsesOfWith(Instruction *I, Value *V,
Worklist.push_back(Use);
// Add users to the worklist which may be simplified now.
- for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
- UI != E; ++UI)
- Worklist.push_back(cast<Instruction>(*UI));
+ for (User *U : I->users())
+ Worklist.push_back(cast<Instruction>(U));
LPM->deleteSimpleAnalysisValue(I, L);
RemoveFromWorklist(I, Worklist);
I->replaceAllUsesWith(V);
@@ -944,17 +939,6 @@ static void ReplaceUsesOfWith(Instruction *I, Value *V,
++NumSimplify;
}
-/// RemoveLoopFromHierarchy - We have discovered that the specified loop has
-/// become unwrapped, either because the backedge was deleted, or because the
-/// edge into the header was removed. If the edge into the header from the
-/// latch block was removed, the loop is unwrapped but subloops are still alive,
-/// so they just reparent loops. If the loops are actually dead, they will be
-/// removed later.
-void LoopUnswitch::RemoveLoopFromHierarchy(Loop *L) {
- LPM->deleteLoopFromQueue(L);
- RemoveLoopFromWorklist(L);
-}
-
// RewriteLoopBodyWithConditionConstant - We know either that the value LIC has
// the value specified by Val in the specified loop, or we know it does NOT have
// that value. Rewrite any uses of LIC or of properties correlated to it.
@@ -986,12 +970,11 @@ void LoopUnswitch::RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC,
Replacement = ConstantInt::get(Type::getInt1Ty(Val->getContext()),
!cast<ConstantInt>(Val)->getZExtValue());
- for (Value::use_iterator UI = LIC->use_begin(), E = LIC->use_end();
- UI != E; ++UI) {
- Instruction *U = dyn_cast<Instruction>(*UI);
- if (!U || !L->contains(U))
+ for (User *U : LIC->users()) {
+ Instruction *UI = dyn_cast<Instruction>(U);
+ if (!UI || !L->contains(UI))
continue;
- Worklist.push_back(U);
+ Worklist.push_back(UI);
}
for (std::vector<Instruction*>::iterator UI = Worklist.begin(),
@@ -1005,20 +988,19 @@ void LoopUnswitch::RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC,
// Otherwise, we don't know the precise value of LIC, but we do know that it
// is certainly NOT "Val". As such, simplify any uses in the loop that we
// can. This case occurs when we unswitch switch statements.
- for (Value::use_iterator UI = LIC->use_begin(), E = LIC->use_end();
- UI != E; ++UI) {
- Instruction *U = dyn_cast<Instruction>(*UI);
- if (!U || !L->contains(U))
+ for (User *U : LIC->users()) {
+ Instruction *UI = dyn_cast<Instruction>(U);
+ if (!UI || !L->contains(UI))
continue;
- Worklist.push_back(U);
+ Worklist.push_back(UI);
// TODO: We could do other simplifications, for example, turning
// 'icmp eq LIC, Val' -> false.
// If we know that LIC is not Val, use this info to simplify code.
- SwitchInst *SI = dyn_cast<SwitchInst>(U);
- if (SI == 0 || !isa<ConstantInt>(Val)) continue;
+ SwitchInst *SI = dyn_cast<SwitchInst>(UI);
+ if (!SI || !isa<ConstantInt>(Val)) continue;
SwitchInst::CaseIt DeadCase = SI->findCaseValue(cast<ConstantInt>(Val));
// Default case is live for multiple values.
OpenPOWER on IntegriCloud