//===- CorrelatedExprs.cpp - Pass to detect and eliminated c.e.'s ---------===//
//
-// Correlated Expression Elimination propogates information from conditional
-// branches to blocks dominated by destinations of the branch. It propogates
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Correlated Expression Elimination propagates information from conditional
+// branches to blocks dominated by destinations of the branch. It propagates
// information from the condition check itself into the body of the branch,
// allowing transformations like these for example:
//
// if (i == 7)
-// ... 4*i; // constant propogation
+// ... 4*i; // constant propagation
//
// M = i+1; N = j+1;
// if (i == j)
//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "cee"
#include "llvm/Transforms/Scalar.h"
+#include "llvm/Constants.h"
#include "llvm/Pass.h"
#include "llvm/Function.h"
-#include "llvm/iTerminators.h"
-#include "llvm/iPHINode.h"
-#include "llvm/iOperators.h"
-#include "llvm/ConstantHandling.h"
-#include "llvm/Assembly/Writer.h"
+#include "llvm/Instructions.h"
+#include "llvm/Type.h"
#include "llvm/Analysis/Dominators.h"
+#include "llvm/Assembly/Writer.h"
#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Support/ConstantRange.h"
#include "llvm/Support/CFG.h"
-#include "Support/PostOrderIterator.h"
-#include "Support/Statistic.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/Statistic.h"
#include <algorithm>
+using namespace llvm;
-namespace {
- Statistic<> NumSetCCRemoved("cee", "Number of setcc instruction eliminated");
- Statistic<> NumOperandsCann("cee", "Number of operands cannonicalized");
- Statistic<> BranchRevectors("cee", "Number of branches revectored");
+STATISTIC(NumCmpRemoved, "Number of cmp instruction eliminated");
+STATISTIC(NumOperandsCann, "Number of operands canonicalized");
+STATISTIC(BranchRevectors, "Number of branches revectored");
+namespace {
class ValueInfo;
class Relation {
- Value *Val; // Relation to what value?
- Instruction::BinaryOps Rel; // SetCC relation, or Add if no information
+ Value *Val; // Relation to what value?
+ unsigned Rel; // SetCC or ICmp relation, or Add if no information
public:
Relation(Value *V) : Val(V), Rel(Instruction::Add) {}
bool operator<(const Relation &R) const { return Val < R.Val; }
Value *getValue() const { return Val; }
- Instruction::BinaryOps getRelation() const { return Rel; }
+ unsigned getRelation() const { return Rel; }
// contradicts - Return true if the relationship specified by the operand
// contradicts already known information.
//
- bool contradicts(Instruction::BinaryOps Rel, const ValueInfo &VI) const;
+ bool contradicts(unsigned Rel, const ValueInfo &VI) const;
// incorporate - Incorporate information in the argument into this relation
// entry. This assumes that the information doesn't contradict itself. If
// any new information is gained, true is returned, otherwise false is
// returned to indicate that nothing was updated.
//
- bool incorporate(Instruction::BinaryOps Rel, ValueInfo &VI);
+ bool incorporate(unsigned Rel, ValueInfo &VI);
// KnownResult - Whether or not this condition determines the result of a
- // setcc in the program. False & True are intentionally 0 & 1 so we can
- // convert to bool by casting after checking for unknown.
+ // setcc or icmp in the program. False & True are intentionally 0 & 1
+ // so we can convert to bool by casting after checking for unknown.
//
enum KnownResult { KnownFalse = 0, KnownTrue = 1, Unknown = 2 };
// the specified relationship is true or false, return that. If we cannot
// determine the result required, return Unknown.
//
- KnownResult getImpliedResult(Instruction::BinaryOps Rel) const;
+ KnownResult getImpliedResult(unsigned Rel) const;
// print - Output this relation to the specified stream
void print(std::ostream &OS) const;
// kept sorted by the Val field.
std::vector<Relation> Relationships;
- // If information about this value is known or propogated from constant
+ // If information about this value is known or propagated from constant
// expressions, this range contains the possible values this value may hold.
ConstantRange Bounds;
void setReplacement(Value *Repl) { Replacement = Repl; }
// getRelation - return the relationship entry for the specified value.
- // This can invalidate references to other Relation's, so use it carefully.
+ // This can invalidate references to other Relations, so use it carefully.
//
Relation &getRelation(Value *V) {
// Binary search for V's entry...
std::vector<Relation>::iterator I =
- std::lower_bound(Relationships.begin(), Relationships.end(), V);
+ std::lower_bound(Relationships.begin(), Relationships.end(),
+ Relation(V));
// If we found the entry, return it...
if (I != Relationships.end() && I->getValue() == V)
const Relation *requestRelation(Value *V) const {
// Binary search for V's entry...
std::vector<Relation>::const_iterator I =
- std::lower_bound(Relationships.begin(), Relationships.end(), V);
+ std::lower_bound(Relationships.begin(), Relationships.end(),
+ Relation(V));
if (I != Relationships.end() && I->getValue() == V)
return &*I;
return 0;
// this region.
BasicBlock *getEntryBlock() const { return BB; }
+ // empty - return true if this region has no information known about it.
+ bool empty() const { return ValueMap.empty(); }
+
const RegionInfo &operator=(const RegionInfo &RI) {
ValueMap = RI.ValueMap;
return *this;
// print - Output information about this region...
void print(std::ostream &OS) const;
+ void dump() const;
// Allow external access.
typedef ValueMapTy::iterator iterator;
if (I != ValueMap.end()) return &I->second;
return 0;
}
+
+ /// removeValueInfo - Remove anything known about V from our records. This
+ /// works whether or not we know anything about V.
+ ///
+ void removeValueInfo(Value *V) {
+ ValueMap.erase(V);
+ }
};
/// CEE - Correlated Expression Elimination
class CEE : public FunctionPass {
std::map<Value*, unsigned> RankMap;
std::map<BasicBlock*, RegionInfo> RegionInfoMap;
- DominatorSet *DS;
+ ETForest *EF;
DominatorTree *DT;
public:
virtual bool runOnFunction(Function &F);
// We don't modify the program, so we preserve all analyses
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<DominatorSet>();
+ AU.addRequired<ETForest>();
AU.addRequired<DominatorTree>();
AU.addRequiredID(BreakCriticalEdgesID);
};
void BuildRankMap(Function &F);
unsigned getRank(Value *V) const {
- if (isa<Constant>(V) || isa<GlobalValue>(V)) return 0;
+ if (isa<Constant>(V)) return 0;
std::map<Value*, unsigned>::const_iterator I = RankMap.find(V);
if (I != RankMap.end()) return I->second;
return 0; // Must be some other global thing
bool TransformRegion(BasicBlock *BB, std::set<BasicBlock*> &VisitedBlocks);
- BasicBlock *isCorrelatedBranchBlock(BasicBlock *BB, RegionInfo &RI);
- void PropogateBranchInfo(BranchInst *BI);
- void PropogateEquality(Value *Op0, Value *Op1, RegionInfo &RI);
- void PropogateRelation(Instruction::BinaryOps Opcode, Value *Op0,
+ bool ForwardCorrelatedEdgeDestination(TerminatorInst *TI, unsigned SuccNo,
+ RegionInfo &RI);
+
+ void ForwardSuccessorTo(TerminatorInst *TI, unsigned Succ, BasicBlock *D,
+ RegionInfo &RI);
+ void ReplaceUsesOfValueInRegion(Value *Orig, Value *New,
+ BasicBlock *RegionDominator);
+ void CalculateRegionExitBlocks(BasicBlock *BB, BasicBlock *OldSucc,
+ std::vector<BasicBlock*> &RegionExitBlocks);
+ void InsertRegionExitMerges(PHINode *NewPHI, Instruction *OldVal,
+ const std::vector<BasicBlock*> &RegionExitBlocks);
+
+ void PropagateBranchInfo(BranchInst *BI);
+ void PropagateSwitchInfo(SwitchInst *SI);
+ void PropagateEquality(Value *Op0, Value *Op1, RegionInfo &RI);
+ void PropagateRelation(unsigned Opcode, Value *Op0,
Value *Op1, RegionInfo &RI);
void UpdateUsersOfValue(Value *V, RegionInfo &RI);
void IncorporateInstruction(Instruction *Inst, RegionInfo &RI);
void ComputeReplacements(RegionInfo &RI);
-
- // getSetCCResult - Given a setcc instruction, determine if the result is
+ // getCmpResult - Given a icmp instruction, determine if the result is
// determined by facts we already know about the region under analysis.
- // Return KnownTrue, KnownFalse, or Unknown based on what we can determine.
- //
- Relation::KnownResult getSetCCResult(SetCondInst *SC, const RegionInfo &RI);
-
+ // Return KnownTrue, KnownFalse, or UnKnown based on what we can determine.
+ Relation::KnownResult getCmpResult(CmpInst *ICI, const RegionInfo &RI);
bool SimplifyBasicBlock(BasicBlock &BB, const RegionInfo &RI);
bool SimplifyInstruction(Instruction *Inst, const RegionInfo &RI);
- };
- RegisterOpt<CEE> X("cee", "Correlated Expression Elimination");
+ };
+ RegisterPass<CEE> X("cee", "Correlated Expression Elimination");
}
-Pass *createCorrelatedExpressionEliminationPass() { return new CEE(); }
+FunctionPass *llvm::createCorrelatedExpressionEliminationPass() {
+ return new CEE();
+}
bool CEE::runOnFunction(Function &F) {
// Traverse the dominator tree, computing information for each node in the
// tree. Note that our traversal will not even touch unreachable basic
// blocks.
- DS = &getAnalysis<DominatorSet>();
+ EF = &getAnalysis<ETForest>();
DT = &getAnalysis<DominatorTree>();
-
+
std::set<BasicBlock*> VisitedBlocks;
- bool Changed = TransformRegion(&F.getEntryNode(), VisitedBlocks);
+ bool Changed = TransformRegion(&F.getEntryBlock(), VisitedBlocks);
RegionInfoMap.clear();
RankMap.clear();
// TransformRegion - Transform the region starting with BB according to the
// calculated region information for the block. Transforming the region
// involves analyzing any information this block provides to successors,
-// propogating the information to successors, and finally transforming
+// propagating the information to successors, and finally transforming
// successors.
//
// This method processes the function in depth first order, which guarantees
ComputeReplacements(RI);
// If debugging, print computed region information...
- DEBUG(RI.print(std::cerr));
+ DEBUG(RI.print(*cerr.stream()));
// Simplify the contents of this block...
bool Changed = SimplifyBasicBlock(*BB, RI);
// Loop over all of the blocks that this block is the immediate dominator for.
// Because all information known in this region is also known in all of the
- // blocks that are dominated by this one, we can safely propogate the
+ // blocks that are dominated by this one, we can safely propagate the
// information down now.
//
DominatorTree::Node *BBN = (*DT)[BB];
- for (unsigned i = 0, e = BBN->getChildren().size(); i != e; ++i) {
- BasicBlock *Dominated = BBN->getChildren()[i]->getNode();
- assert(RegionInfoMap.find(Dominated) == RegionInfoMap.end() &&
- "RegionInfo should be calculated in dominanace order!");
- getRegionInfo(Dominated) = RI;
- }
+ if (!RI.empty()) // Time opt: only propagate if we can change something
+ for (unsigned i = 0, e = BBN->getChildren().size(); i != e; ++i) {
+ BasicBlock *Dominated = BBN->getChildren()[i]->getBlock();
+ assert(RegionInfoMap.find(Dominated) == RegionInfoMap.end() &&
+ "RegionInfo should be calculated in dominanace order!");
+ getRegionInfo(Dominated) = RI;
+ }
// Now that all of our successors have information if they deserve it,
- // propogate any information our terminator instruction finds to our
+ // propagate any information our terminator instruction finds to our
// successors.
- if (BranchInst *BI = dyn_cast<BranchInst>(TI))
+ if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
if (BI->isConditional())
- PropogateBranchInfo(BI);
+ PropagateBranchInfo(BI);
+ } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
+ PropagateSwitchInfo(SI);
+ }
// If this is a branch to a block outside our region that simply performs
// another conditional branch, one whose outcome is known inside of this
// region, then vector this outgoing edge directly to the known destination.
//
for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
- while (BasicBlock *Dest = isCorrelatedBranchBlock(TI->getSuccessor(i), RI)){
- // If there are any PHI nodes in the Dest BB, we must duplicate the entry
- // in the PHI node for the old successor to now include an entry from the
- // current basic block.
- //
- BasicBlock *OldSucc = TI->getSuccessor(i);
-
- // Loop over all of the PHI nodes...
- for (BasicBlock::iterator I = Dest->begin();
- PHINode *PN = dyn_cast<PHINode>(&*I); ++I) {
- // Find the entry in the PHI node for OldSucc, create a duplicate entry
- // for BB now.
- int BlockIndex = PN->getBasicBlockIndex(OldSucc);
- assert(BlockIndex != -1 && "Block should have entry in PHI!");
- PN->addIncoming(PN->getIncomingValue(BlockIndex), BB);
- }
-
- // Actually revector the branch now...
- TI->setSuccessor(i, Dest);
+ while (ForwardCorrelatedEdgeDestination(TI, i, RI)) {
++BranchRevectors;
Changed = true;
}
// Now that all of our successors have information, recursively process them.
for (unsigned i = 0, e = BBN->getChildren().size(); i != e; ++i)
- Changed |= TransformRegion(BBN->getChildren()[i]->getNode(), VisitedBlocks);
+ Changed |= TransformRegion(BBN->getChildren()[i]->getBlock(),VisitedBlocks);
return Changed;
}
-// If this block is a simple block not in the current region, which contains
-// only a conditional branch, we determine if the outcome of the branch can be
-// determined from information inside of the region. Instead of going to this
-// block, we can instead go to the destination we know is the right target.
+// isBlockSimpleEnoughForCheck to see if the block is simple enough for us to
+// revector the conditional branch in the bottom of the block, do so now.
//
-BasicBlock *CEE::isCorrelatedBranchBlock(BasicBlock *BB, RegionInfo &RI) {
+static bool isBlockSimpleEnough(BasicBlock *BB) {
+ assert(isa<BranchInst>(BB->getTerminator()));
+ BranchInst *BI = cast<BranchInst>(BB->getTerminator());
+ assert(BI->isConditional());
+
+ // Check the common case first: empty block, or block with just a setcc.
+ if (BB->size() == 1 ||
+ (BB->size() == 2 && &BB->front() == BI->getCondition() &&
+ BI->getCondition()->hasOneUse()))
+ return true;
+
+ // Check the more complex case now...
+ BasicBlock::iterator I = BB->begin();
+
+ // FIXME: This should be reenabled once the regression with SIM is fixed!
+#if 0
+ // PHI Nodes are ok, just skip over them...
+ while (isa<PHINode>(*I)) ++I;
+#endif
+
+ // Accept the setcc instruction...
+ if (&*I == BI->getCondition())
+ ++I;
+
+ // Nothing else is acceptable here yet. We must not revector... unless we are
+ // at the terminator instruction.
+ if (&*I == BI)
+ return true;
+
+ return false;
+}
+
+
+bool CEE::ForwardCorrelatedEdgeDestination(TerminatorInst *TI, unsigned SuccNo,
+ RegionInfo &RI) {
+ // If this successor is a simple block not in the current region, which
+ // contains only a conditional branch, we decide if the outcome of the branch
+ // can be determined from information inside of the region. Instead of going
+ // to this block, we can instead go to the destination we know is the right
+ // target.
+ //
+
// Check to see if we dominate the block. If so, this block will get the
// condition turned to a constant anyway.
//
- //if (DS->dominates(RI.getEntryBlock(), BB))
+ //if (EF->dominates(RI.getEntryBlock(), BB))
// return 0;
- // Check to see if this is a conditional branch...
- if (BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator()))
- if (BI->isConditional()) {
- // Make sure that the block is either empty, or only contains a setcc.
- if (BB->size() == 1 ||
- (BB->size() == 2 && &BB->front() == BI->getCondition() &&
- BI->getCondition()->use_size() == 1))
- if (SetCondInst *SCI = dyn_cast<SetCondInst>(BI->getCondition())) {
- Relation::KnownResult Result = getSetCCResult(SCI, RI);
-
- if (Result == Relation::KnownTrue)
- return BI->getSuccessor(0);
- else if (Result == Relation::KnownFalse)
- return BI->getSuccessor(1);
- }
+ BasicBlock *BB = TI->getParent();
+
+ // Get the destination block of this edge...
+ BasicBlock *OldSucc = TI->getSuccessor(SuccNo);
+
+ // Make sure that the block ends with a conditional branch and is simple
+ // enough for use to be able to revector over.
+ BranchInst *BI = dyn_cast<BranchInst>(OldSucc->getTerminator());
+ if (BI == 0 || !BI->isConditional() || !isBlockSimpleEnough(OldSucc))
+ return false;
+
+ // We can only forward the branch over the block if the block ends with a
+ // cmp we can determine the outcome for.
+ //
+ // FIXME: we can make this more generic. Code below already handles more
+ // generic case.
+ if (!isa<CmpInst>(BI->getCondition()))
+ return false;
+
+ // Make a new RegionInfo structure so that we can simulate the effect of the
+ // PHI nodes in the block we are skipping over...
+ //
+ RegionInfo NewRI(RI);
+
+ // Remove value information for all of the values we are simulating... to make
+ // sure we don't have any stale information.
+ for (BasicBlock::iterator I = OldSucc->begin(), E = OldSucc->end(); I!=E; ++I)
+ if (I->getType() != Type::VoidTy)
+ NewRI.removeValueInfo(I);
+
+ // Put the newly discovered information into the RegionInfo...
+ for (BasicBlock::iterator I = OldSucc->begin(), E = OldSucc->end(); I!=E; ++I)
+ if (PHINode *PN = dyn_cast<PHINode>(I)) {
+ int OpNum = PN->getBasicBlockIndex(BB);
+ assert(OpNum != -1 && "PHI doesn't have incoming edge for predecessor!?");
+ PropagateEquality(PN, PN->getIncomingValue(OpNum), NewRI);
+ } else if (CmpInst *CI = dyn_cast<CmpInst>(I)) {
+ Relation::KnownResult Res = getCmpResult(CI, NewRI);
+ if (Res == Relation::Unknown) return false;
+ PropagateEquality(CI, ConstantBool::get(Res), NewRI);
+ } else {
+ assert(isa<BranchInst>(*I) && "Unexpected instruction type!");
+ }
+
+ // Compute the facts implied by what we have discovered...
+ ComputeReplacements(NewRI);
+
+ ValueInfo &PredicateVI = NewRI.getValueInfo(BI->getCondition());
+ if (PredicateVI.getReplacement() &&
+ isa<Constant>(PredicateVI.getReplacement()) &&
+ !isa<GlobalValue>(PredicateVI.getReplacement())) {
+ ConstantBool *CB = cast<ConstantBool>(PredicateVI.getReplacement());
+
+ // Forward to the successor that corresponds to the branch we will take.
+ ForwardSuccessorTo(TI, SuccNo, BI->getSuccessor(!CB->getValue()), NewRI);
+ return true;
+ }
+
+ return false;
+}
+
+static Value *getReplacementOrValue(Value *V, RegionInfo &RI) {
+ if (const ValueInfo *VI = RI.requestValueInfo(V))
+ if (Value *Repl = VI->getReplacement())
+ return Repl;
+ return V;
+}
+
+/// ForwardSuccessorTo - We have found that we can forward successor # 'SuccNo'
+/// of Terminator 'TI' to the 'Dest' BasicBlock. This method performs the
+/// mechanics of updating SSA information and revectoring the branch.
+///
+void CEE::ForwardSuccessorTo(TerminatorInst *TI, unsigned SuccNo,
+ BasicBlock *Dest, RegionInfo &RI) {
+ // If there are any PHI nodes in the Dest BB, we must duplicate the entry
+ // in the PHI node for the old successor to now include an entry from the
+ // current basic block.
+ //
+ BasicBlock *OldSucc = TI->getSuccessor(SuccNo);
+ BasicBlock *BB = TI->getParent();
+
+ DOUT << "Forwarding branch in basic block %" << BB->getName()
+ << " from block %" << OldSucc->getName() << " to block %"
+ << Dest->getName() << "\n"
+ << "Before forwarding: " << *BB->getParent();
+
+ // Because we know that there cannot be critical edges in the flow graph, and
+ // that OldSucc has multiple outgoing edges, this means that Dest cannot have
+ // multiple incoming edges.
+ //
+#ifndef NDEBUG
+ pred_iterator DPI = pred_begin(Dest); ++DPI;
+ assert(DPI == pred_end(Dest) && "Critical edge found!!");
+#endif
+
+ // Loop over any PHI nodes in the destination, eliminating them, because they
+ // may only have one input.
+ //
+ while (PHINode *PN = dyn_cast<PHINode>(&Dest->front())) {
+ assert(PN->getNumIncomingValues() == 1 && "Crit edge found!");
+ // Eliminate the PHI node
+ PN->replaceAllUsesWith(PN->getIncomingValue(0));
+ Dest->getInstList().erase(PN);
+ }
+
+ // If there are values defined in the "OldSucc" basic block, we need to insert
+ // PHI nodes in the regions we are dealing with to emulate them. This can
+ // insert dead phi nodes, but it is more trouble to see if they are used than
+ // to just blindly insert them.
+ //
+ if (EF->dominates(OldSucc, Dest)) {
+ // RegionExitBlocks - Find all of the blocks that are not dominated by Dest,
+ // but have predecessors that are. Additionally, prune down the set to only
+ // include blocks that are dominated by OldSucc as well.
+ //
+ std::vector<BasicBlock*> RegionExitBlocks;
+ CalculateRegionExitBlocks(Dest, OldSucc, RegionExitBlocks);
+
+ for (BasicBlock::iterator I = OldSucc->begin(), E = OldSucc->end();
+ I != E; ++I)
+ if (I->getType() != Type::VoidTy) {
+ // Create and insert the PHI node into the top of Dest.
+ PHINode *NewPN = new PHINode(I->getType(), I->getName()+".fw_merge",
+ Dest->begin());
+ // There is definitely an edge from OldSucc... add the edge now
+ NewPN->addIncoming(I, OldSucc);
+
+ // There is also an edge from BB now, add the edge with the calculated
+ // value from the RI.
+ NewPN->addIncoming(getReplacementOrValue(I, RI), BB);
+
+ // Make everything in the Dest region use the new PHI node now...
+ ReplaceUsesOfValueInRegion(I, NewPN, Dest);
+
+ // Make sure that exits out of the region dominated by NewPN get PHI
+ // nodes that merge the values as appropriate.
+ InsertRegionExitMerges(NewPN, I, RegionExitBlocks);
+ }
+ }
+
+ // If there were PHI nodes in OldSucc, we need to remove the entry for this
+ // edge from the PHI node, and we need to replace any references to the PHI
+ // node with a new value.
+ //
+ for (BasicBlock::iterator I = OldSucc->begin(); isa<PHINode>(I); ) {
+ PHINode *PN = cast<PHINode>(I);
+
+ // Get the value flowing across the old edge and remove the PHI node entry
+ // for this edge: we are about to remove the edge! Don't remove the PHI
+ // node yet though if this is the last edge into it.
+ Value *EdgeValue = PN->removeIncomingValue(BB, false);
+
+ // Make sure that anything that used to use PN now refers to EdgeValue
+ ReplaceUsesOfValueInRegion(PN, EdgeValue, Dest);
+
+ // If there is only one value left coming into the PHI node, replace the PHI
+ // node itself with the one incoming value left.
+ //
+ if (PN->getNumIncomingValues() == 1) {
+ assert(PN->getNumIncomingValues() == 1);
+ PN->replaceAllUsesWith(PN->getIncomingValue(0));
+ PN->getParent()->getInstList().erase(PN);
+ I = OldSucc->begin();
+ } else if (PN->getNumIncomingValues() == 0) { // Nuke the PHI
+ // If we removed the last incoming value to this PHI, nuke the PHI node
+ // now.
+ PN->replaceAllUsesWith(Constant::getNullValue(PN->getType()));
+ PN->getParent()->getInstList().erase(PN);
+ I = OldSucc->begin();
+ } else {
+ ++I; // Otherwise, move on to the next PHI node
+ }
+ }
+
+ // Actually revector the branch now...
+ TI->setSuccessor(SuccNo, Dest);
+
+ // If we just introduced a critical edge in the flow graph, make sure to break
+ // it right away...
+ SplitCriticalEdge(TI, SuccNo, this);
+
+ // Make sure that we don't introduce critical edges from oldsucc now!
+ for (unsigned i = 0, e = OldSucc->getTerminator()->getNumSuccessors();
+ i != e; ++i)
+ SplitCriticalEdge(OldSucc->getTerminator(), i, this);
+
+ // Since we invalidated the CFG, recalculate the dominator set so that it is
+ // useful for later processing!
+ // FIXME: This is much worse than it really should be!
+ //EF->recalculate();
+
+ DOUT << "After forwarding: " << *BB->getParent();
+}
+
+/// ReplaceUsesOfValueInRegion - This method replaces all uses of Orig with uses
+/// of New. It only affects instructions that are defined in basic blocks that
+/// are dominated by Head.
+///
+void CEE::ReplaceUsesOfValueInRegion(Value *Orig, Value *New,
+ BasicBlock *RegionDominator) {
+ assert(Orig != New && "Cannot replace value with itself");
+ std::vector<Instruction*> InstsToChange;
+ std::vector<PHINode*> PHIsToChange;
+ InstsToChange.reserve(Orig->getNumUses());
+
+ // Loop over instructions adding them to InstsToChange vector, this allows us
+ // an easy way to avoid invalidating the use_iterator at a bad time.
+ for (Value::use_iterator I = Orig->use_begin(), E = Orig->use_end();
+ I != E; ++I)
+ if (Instruction *User = dyn_cast<Instruction>(*I))
+ if (EF->dominates(RegionDominator, User->getParent()))
+ InstsToChange.push_back(User);
+ else if (PHINode *PN = dyn_cast<PHINode>(User)) {
+ PHIsToChange.push_back(PN);
+ }
+
+ // PHIsToChange contains PHI nodes that use Orig that do not live in blocks
+ // dominated by orig. If the block the value flows in from is dominated by
+ // RegionDominator, then we rewrite the PHI
+ for (unsigned i = 0, e = PHIsToChange.size(); i != e; ++i) {
+ PHINode *PN = PHIsToChange[i];
+ for (unsigned j = 0, e = PN->getNumIncomingValues(); j != e; ++j)
+ if (PN->getIncomingValue(j) == Orig &&
+ EF->dominates(RegionDominator, PN->getIncomingBlock(j)))
+ PN->setIncomingValue(j, New);
+ }
+
+ // Loop over the InstsToChange list, replacing all uses of Orig with uses of
+ // New. This list contains all of the instructions in our region that use
+ // Orig.
+ for (unsigned i = 0, e = InstsToChange.size(); i != e; ++i)
+ if (PHINode *PN = dyn_cast<PHINode>(InstsToChange[i])) {
+ // PHINodes must be handled carefully. If the PHI node itself is in the
+ // region, we have to make sure to only do the replacement for incoming
+ // values that correspond to basic blocks in the region.
+ for (unsigned j = 0, e = PN->getNumIncomingValues(); j != e; ++j)
+ if (PN->getIncomingValue(j) == Orig &&
+ EF->dominates(RegionDominator, PN->getIncomingBlock(j)))
+ PN->setIncomingValue(j, New);
+
+ } else {
+ InstsToChange[i]->replaceUsesOfWith(Orig, New);
+ }
+}
+
+static void CalcRegionExitBlocks(BasicBlock *Header, BasicBlock *BB,
+ std::set<BasicBlock*> &Visited,
+ ETForest &EF,
+ std::vector<BasicBlock*> &RegionExitBlocks) {
+ if (Visited.count(BB)) return;
+ Visited.insert(BB);
+
+ if (EF.dominates(Header, BB)) { // Block in the region, recursively traverse
+ for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I)
+ CalcRegionExitBlocks(Header, *I, Visited, EF, RegionExitBlocks);
+ } else {
+ // Header does not dominate this block, but we have a predecessor that does
+ // dominate us. Add ourself to the list.
+ RegionExitBlocks.push_back(BB);
+ }
+}
+
+/// CalculateRegionExitBlocks - Find all of the blocks that are not dominated by
+/// BB, but have predecessors that are. Additionally, prune down the set to
+/// only include blocks that are dominated by OldSucc as well.
+///
+void CEE::CalculateRegionExitBlocks(BasicBlock *BB, BasicBlock *OldSucc,
+ std::vector<BasicBlock*> &RegionExitBlocks){
+ std::set<BasicBlock*> Visited; // Don't infinite loop
+
+ // Recursively calculate blocks we are interested in...
+ CalcRegionExitBlocks(BB, BB, Visited, *EF, RegionExitBlocks);
+
+ // Filter out blocks that are not dominated by OldSucc...
+ for (unsigned i = 0; i != RegionExitBlocks.size(); ) {
+ if (EF->dominates(OldSucc, RegionExitBlocks[i]))
+ ++i; // Block is ok, keep it.
+ else {
+ // Move to end of list...
+ std::swap(RegionExitBlocks[i], RegionExitBlocks.back());
+ RegionExitBlocks.pop_back(); // Nuke the end
}
- return 0;
+ }
}
+void CEE::InsertRegionExitMerges(PHINode *BBVal, Instruction *OldVal,
+ const std::vector<BasicBlock*> &RegionExitBlocks) {
+ assert(BBVal->getType() == OldVal->getType() && "Should be derived values!");
+ BasicBlock *BB = BBVal->getParent();
+
+ // Loop over all of the blocks we have to place PHIs in, doing it.
+ for (unsigned i = 0, e = RegionExitBlocks.size(); i != e; ++i) {
+ BasicBlock *FBlock = RegionExitBlocks[i]; // Block on the frontier
+
+ // Create the new PHI node
+ PHINode *NewPN = new PHINode(BBVal->getType(),
+ OldVal->getName()+".fw_frontier",
+ FBlock->begin());
+
+ // Add an incoming value for every predecessor of the block...
+ for (pred_iterator PI = pred_begin(FBlock), PE = pred_end(FBlock);
+ PI != PE; ++PI) {
+ // If the incoming edge is from the region dominated by BB, use BBVal,
+ // otherwise use OldVal.
+ NewPN->addIncoming(EF->dominates(BB, *PI) ? BBVal : OldVal, *PI);
+ }
+
+ // Now make everyone dominated by this block use this new value!
+ ReplaceUsesOfValueInRegion(OldVal, NewPN, FBlock);
+ }
+}
+
+
+
// BuildRankMap - This method builds the rank map data structure which gives
// each instruction/value in the function a value based on how early it appears
// in the function. We give constants and globals rank 0, arguments are
unsigned Rank = 1; // Skip rank zero.
// Number the arguments...
- for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
+ for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
RankMap[I] = Rank++;
// Number the instructions in reverse post order...
}
-// PropogateBranchInfo - When this method is invoked, we need to propogate
+// PropagateBranchInfo - When this method is invoked, we need to propagate
// information derived from the branch condition into the true and false
// branches of BI. Since we know that there aren't any critical edges in the
// flow graph, this can proceed unconditionally.
//
-void CEE::PropogateBranchInfo(BranchInst *BI) {
+void CEE::PropagateBranchInfo(BranchInst *BI) {
assert(BI->isConditional() && "Must be a conditional branch!");
- BasicBlock *BB = BI->getParent();
- BasicBlock *TrueBB = BI->getSuccessor(0);
- BasicBlock *FalseBB = BI->getSuccessor(1);
- // Propogate information into the true block...
+ // Propagate information into the true block...
+ //
+ PropagateEquality(BI->getCondition(), ConstantBool::getTrue(),
+ getRegionInfo(BI->getSuccessor(0)));
+
+ // Propagate information into the false block...
//
- PropogateEquality(BI->getCondition(), ConstantBool::True,
- getRegionInfo(TrueBB));
-
- // Propogate information into the false block...
+ PropagateEquality(BI->getCondition(), ConstantBool::getFalse(),
+ getRegionInfo(BI->getSuccessor(1)));
+}
+
+
+// PropagateSwitchInfo - We need to propagate the value tested by the
+// switch statement through each case block.
+//
+void CEE::PropagateSwitchInfo(SwitchInst *SI) {
+ // Propagate information down each of our non-default case labels. We
+ // don't yet propagate information down the default label, because a
+ // potentially large number of inequality constraints provide less
+ // benefit per unit work than a single equality constraint.
//
- PropogateEquality(BI->getCondition(), ConstantBool::False,
- getRegionInfo(FalseBB));
+ Value *cond = SI->getCondition();
+ for (unsigned i = 1; i < SI->getNumSuccessors(); ++i)
+ PropagateEquality(cond, SI->getSuccessorValue(i),
+ getRegionInfo(SI->getSuccessor(i)));
}
-// PropogateEquality - If we discover that two values are equal to each other in
-// a specified region, propogate this knowledge recursively.
+// PropagateEquality - If we discover that two values are equal to each other in
+// a specified region, propagate this knowledge recursively.
//
-void CEE::PropogateEquality(Value *Op0, Value *Op1, RegionInfo &RI) {
+void CEE::PropagateEquality(Value *Op0, Value *Op1, RegionInfo &RI) {
if (Op0 == Op1) return; // Gee whiz. Are these really equal each other?
if (isa<Constant>(Op0)) // Make sure the constant is always Op1
Relation &KnownRelation = VI.getRelation(Op1);
// If we already know they're equal, don't reprocess...
- if (KnownRelation.getRelation() == Instruction::SetEQ)
+ if (KnownRelation.getRelation() == FCmpInst::FCMP_OEQ ||
+ KnownRelation.getRelation() == ICmpInst::ICMP_EQ)
return;
// If this is boolean, check to see if one of the operands is a constant. If
// as well.
//
if (CB->getValue() && Inst->getOpcode() == Instruction::And) {
- PropogateEquality(Inst->getOperand(0), CB, RI);
- PropogateEquality(Inst->getOperand(1), CB, RI);
+ PropagateEquality(Inst->getOperand(0), CB, RI);
+ PropagateEquality(Inst->getOperand(1), CB, RI);
}
-
+
// If we know that this instruction is an OR instruction, and the result
// is false, this means that both operands to the OR are know to be false
// as well.
//
if (!CB->getValue() && Inst->getOpcode() == Instruction::Or) {
- PropogateEquality(Inst->getOperand(0), CB, RI);
- PropogateEquality(Inst->getOperand(1), CB, RI);
+ PropagateEquality(Inst->getOperand(0), CB, RI);
+ PropagateEquality(Inst->getOperand(1), CB, RI);
}
-
+
// If we know that this instruction is a NOT instruction, we know that the
// operand is known to be the inverse of whatever the current value is.
//
if (BinaryOperator *BOp = dyn_cast<BinaryOperator>(Inst))
if (BinaryOperator::isNot(BOp))
- PropogateEquality(BinaryOperator::getNotArgument(BOp),
+ PropagateEquality(BinaryOperator::getNotArgument(BOp),
ConstantBool::get(!CB->getValue()), RI);
- // If we know the value of a SetCC instruction, propogate the information
+ // If we know the value of a FCmp instruction, propagate the information
// about the relation into this region as well.
//
- if (SetCondInst *SCI = dyn_cast<SetCondInst>(Inst)) {
+ if (FCmpInst *FCI = dyn_cast<FCmpInst>(Inst)) {
if (CB->getValue()) { // If we know the condition is true...
- // Propogate info about the LHS to the RHS & RHS to LHS
- PropogateRelation(SCI->getOpcode(), SCI->getOperand(0),
- SCI->getOperand(1), RI);
- PropogateRelation(SCI->getSwappedCondition(),
- SCI->getOperand(1), SCI->getOperand(0), RI);
+ // Propagate info about the LHS to the RHS & RHS to LHS
+ PropagateRelation(FCI->getPredicate(), FCI->getOperand(0),
+ FCI->getOperand(1), RI);
+ PropagateRelation(FCI->getSwappedPredicate(),
+ FCI->getOperand(1), FCI->getOperand(0), RI);
} else { // If we know the condition is false...
// We know the opposite of the condition is true...
- Instruction::BinaryOps C = SCI->getInverseCondition();
-
- PropogateRelation(C, SCI->getOperand(0), SCI->getOperand(1), RI);
- PropogateRelation(SetCondInst::getSwappedCondition(C),
- SCI->getOperand(1), SCI->getOperand(0), RI);
+ FCmpInst::Predicate C = FCI->getInversePredicate();
+
+ PropagateRelation(C, FCI->getOperand(0), FCI->getOperand(1), RI);
+ PropagateRelation(FCmpInst::getSwappedPredicate(C),
+ FCI->getOperand(1), FCI->getOperand(0), RI);
+ }
+ }
+
+ // If we know the value of a ICmp instruction, propagate the information
+ // about the relation into this region as well.
+ //
+ if (ICmpInst *ICI = dyn_cast<ICmpInst>(Inst)) {
+ if (CB->getValue()) { // If we know the condition is true...
+ // Propagate info about the LHS to the RHS & RHS to LHS
+ PropagateRelation(ICI->getPredicate(), ICI->getOperand(0),
+ ICI->getOperand(1), RI);
+ PropagateRelation(ICI->getSwappedPredicate(), ICI->getOperand(1),
+ ICI->getOperand(1), RI);
+
+ } else { // If we know the condition is false ...
+ // We know the opposite of the condition is true...
+ ICmpInst::Predicate C = ICI->getInversePredicate();
+
+ PropagateRelation(C, ICI->getOperand(0), ICI->getOperand(1), RI);
+ PropagateRelation(ICmpInst::getSwappedPredicate(C),
+ ICI->getOperand(1), ICI->getOperand(0), RI);
}
}
}
}
- // Propogate information about Op0 to Op1 & visa versa
- PropogateRelation(Instruction::SetEQ, Op0, Op1, RI);
- PropogateRelation(Instruction::SetEQ, Op1, Op0, RI);
+ // Propagate information about Op0 to Op1 & visa versa
+ PropagateRelation(ICmpInst::ICMP_EQ, Op0, Op1, RI);
+ PropagateRelation(ICmpInst::ICMP_EQ, Op1, Op0, RI);
+ PropagateRelation(FCmpInst::FCMP_OEQ, Op0, Op1, RI);
+ PropagateRelation(FCmpInst::FCMP_OEQ, Op1, Op0, RI);
}
-// PropogateRelation - We know that the specified relation is true in all of the
-// blocks in the specified region. Propogate the information about Op0 and
+// PropagateRelation - We know that the specified relation is true in all of the
+// blocks in the specified region. Propagate the information about Op0 and
// anything derived from it into this region.
//
-void CEE::PropogateRelation(Instruction::BinaryOps Opcode, Value *Op0,
+void CEE::PropagateRelation(unsigned Opcode, Value *Op0,
Value *Op1, RegionInfo &RI) {
assert(Op0->getType() == Op1->getType() && "Equal types expected!");
// Constants are already pretty well understood. We will apply information
- // about the constant to Op1 in another call to PropogateRelation.
+ // about the constant to Op1 in another call to PropagateRelation.
//
if (isa<Constant>(Op0)) return;
return;
// If we already have information that contradicts the current information we
- // are propogating, ignore this info. Something bad must have happened!
+ // are propagating, ignore this info. Something bad must have happened!
//
if (Op1R.contradicts(Opcode, VI)) {
Op1R.contradicts(Opcode, VI);
- std::cerr << "Contradiction found for opcode: "
- << Instruction::getOpcodeName(Opcode) << "\n";
- Op1R.print(std::cerr);
+ cerr << "Contradiction found for opcode: "
+ << ((isa<ICmpInst>(Op0)||isa<ICmpInst>(Op1)) ?
+ Instruction::getOpcodeName(Instruction::ICmp) :
+ Instruction::getOpcodeName(Opcode))
+ << "\n";
+ Op1R.print(*cerr.stream());
return;
}
- // If the information propogted is new, then we want process the uses of this
- // instruction to propogate the information down to them.
+ // If the information propagated is new, then we want process the uses of this
+ // instruction to propagate the information down to them.
//
if (Op1R.incorporate(Opcode, VI))
UpdateUsersOfValue(Op0, RI);
// UpdateUsersOfValue - The information about V in this region has been updated.
-// Propogate this to all consumers of the value.
+// Propagate this to all consumers of the value.
//
void CEE::UpdateUsersOfValue(Value *V, RegionInfo &RI) {
for (Value::use_iterator I = V->use_begin(), E = V->use_end();
I != E; ++I)
if (Instruction *Inst = dyn_cast<Instruction>(*I)) {
// If this is an instruction using a value that we know something about,
- // try to propogate information to the value produced by the
+ // try to propagate information to the value produced by the
// instruction. We can only do this if it is an instruction we can
- // propogate information for (a setcc for example), and we only WANT to
+ // propagate information for (a setcc for example), and we only WANT to
// do this if the instruction dominates this region.
//
// If the instruction doesn't dominate this region, then it cannot be
// here. This check is also effectively checking to make sure that Inst
// is in the same function as our region (in case V is a global f.e.).
//
- if (DS->properlyDominates(Inst->getParent(), RI.getEntryBlock()))
+ if (EF->properlyDominates(Inst->getParent(), RI.getEntryBlock()))
IncorporateInstruction(Inst, RI);
}
}
// value produced by this instruction
//
void CEE::IncorporateInstruction(Instruction *Inst, RegionInfo &RI) {
- if (SetCondInst *SCI = dyn_cast<SetCondInst>(Inst)) {
+ if (CmpInst *CI = dyn_cast<CmpInst>(Inst)) {
// See if we can figure out a result for this instruction...
- Relation::KnownResult Result = getSetCCResult(SCI, RI);
+ Relation::KnownResult Result = getCmpResult(CI, RI);
if (Result != Relation::Unknown) {
- PropogateEquality(SCI, Result ? ConstantBool::True : ConstantBool::False,
- RI);
+ PropagateEquality(CI, ConstantBool::get(Result != 0), RI);
}
}
}
// X and a constant C, we can replace all uses of X with C in the region we are
// interested in. We generalize this replacement to replace variables with
// other variables if they are equal and there is a variable with lower rank
-// than the current one. This offers a cannonicalizing property that exposes
+// than the current one. This offers a canonicalizing property that exposes
// more redundancies for later transformations to take advantage of.
//
void CEE::ComputeReplacements(RegionInfo &RI) {
// Loop over the relationships known about Op0.
const std::vector<Relation> &Relationships = VI.getRelationships();
for (unsigned i = 0, e = Relationships.size(); i != e; ++i)
- if (Relationships[i].getRelation() == Instruction::SetEQ) {
+ if (Relationships[i].getRelation() == FCmpInst::FCMP_OEQ) {
+ unsigned R = getRank(Relationships[i].getValue());
+ if (R < MinRank) {
+ MinRank = R;
+ Replacement = Relationships[i].getValue();
+ }
+ }
+ else if (Relationships[i].getRelation() == ICmpInst::ICMP_EQ) {
unsigned R = getRank(Relationships[i].getValue());
if (R < MinRank) {
MinRank = R;
bool CEE::SimplifyBasicBlock(BasicBlock &BB, const RegionInfo &RI) {
bool Changed = false;
for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ) {
- Instruction *Inst = &*I++;
+ Instruction *Inst = I++;
// Convert instruction arguments to canonical forms...
Changed |= SimplifyInstruction(Inst, RI);
- if (SetCondInst *SCI = dyn_cast<SetCondInst>(Inst)) {
+ if (CmpInst *CI = dyn_cast<CmpInst>(Inst)) {
// Try to simplify a setcc instruction based on inherited information
- Relation::KnownResult Result = getSetCCResult(SCI, RI);
+ Relation::KnownResult Result = getCmpResult(CI, RI);
if (Result != Relation::Unknown) {
- DEBUG(std::cerr << "Replacing setcc with " << Result
- << " constant: " << SCI);
+ DEBUG(cerr << "Replacing icmp with " << Result
+ << " constant: " << *CI);
- SCI->replaceAllUsesWith(ConstantBool::get((bool)Result));
+ CI->replaceAllUsesWith(ConstantBool::get((bool)Result));
// The instruction is now dead, remove it from the program.
- SCI->getParent()->getInstList().erase(SCI);
- ++NumSetCCRemoved;
+ CI->getParent()->getInstList().erase(CI);
+ ++NumCmpRemoved;
Changed = true;
}
}
}
// SimplifyInstruction - Inspect the operands of the instruction, converting
-// them to their cannonical form if possible. This takes care of, for example,
+// them to their canonical form if possible. This takes care of, for example,
// replacing a value 'X' with a constant 'C' if the instruction in question is
// dominated by a true seteq 'X', 'C'.
//
if (Value *Repl = VI->getReplacement()) {
// If we know if a replacement with lower rank than Op0, make the
// replacement now.
- DEBUG(std::cerr << "In Inst: " << I << " Replacing operand #" << i
- << " with " << Repl << "\n");
+ DOUT << "In Inst: " << *I << " Replacing operand #" << i
+ << " with " << *Repl << "\n";
I->setOperand(i, Repl);
Changed = true;
++NumOperandsCann;
return Changed;
}
-
-// SimplifySetCC - Try to simplify a setcc instruction based on information
-// inherited from a dominating setcc instruction. V is one of the operands to
-// the setcc instruction, and VI is the set of information known about it. We
+// getCmpResult - Try to simplify a cmp instruction based on information
+// inherited from a dominating icmp instruction. V is one of the operands to
+// the icmp instruction, and VI is the set of information known about it. We
// take two cases into consideration here. If the comparison is against a
// constant value, we can use the constant range to see if the comparison is
// possible to succeed. If it is not a comparison against a constant, we check
// to see if there is a known relationship between the two values. If so, we
// may be able to eliminate the check.
//
-Relation::KnownResult CEE::getSetCCResult(SetCondInst *SCI,
- const RegionInfo &RI) {
- Value *Op0 = SCI->getOperand(0), *Op1 = SCI->getOperand(1);
- Instruction::BinaryOps Opcode = SCI->getOpcode();
-
+Relation::KnownResult CEE::getCmpResult(CmpInst *CI,
+ const RegionInfo &RI) {
+ Value *Op0 = CI->getOperand(0), *Op1 = CI->getOperand(1);
+ unsigned short predicate = CI->getPredicate();
+
if (isa<Constant>(Op0)) {
if (isa<Constant>(Op1)) {
- if (Constant *Result = ConstantFoldInstruction(SCI)) {
- // Wow, this is easy, directly eliminate the SetCondInst.
- DEBUG(std::cerr << "Replacing setcc with constant fold: " << SCI);
+ if (Constant *Result = ConstantFoldInstruction(CI)) {
+ // Wow, this is easy, directly eliminate the ICmpInst.
+ DEBUG(cerr << "Replacing cmp with constant fold: " << *CI);
return cast<ConstantBool>(Result)->getValue()
? Relation::KnownTrue : Relation::KnownFalse;
}
} else {
// We want to swap this instruction so that operand #0 is the constant.
std::swap(Op0, Op1);
- Opcode = SCI->getSwappedCondition();
+ if (isa<ICmpInst>(CI))
+ predicate = cast<ICmpInst>(CI)->getSwappedPredicate();
+ else
+ predicate = cast<FCmpInst>(CI)->getSwappedPredicate();
}
}
// At this point, we know that if we have a constant argument that it is in
// Op1. Check to see if we know anything about comparing value with a
- // constant, and if we can use this info to fold the setcc.
+ // constant, and if we can use this info to fold the icmp.
//
if (ConstantIntegral *C = dyn_cast<ConstantIntegral>(Op1)) {
// Check to see if we already know the result of this comparison...
- ConstantRange R = ConstantRange(Opcode, C);
- ConstantRange Int = R.intersectWith(Op0VI->getBounds());
+ ConstantRange R = ConstantRange(predicate, C);
+ ConstantRange Int = R.intersectWith(Op0VI->getBounds(),
+ ICmpInst::isSignedPredicate(ICmpInst::Predicate(predicate)));
// If the intersection of the two ranges is empty, then the condition
// could never be true!
- //
+ //
if (Int.isEmptySet()) {
Result = Relation::KnownFalse;
//
// Do we have value information about Op0 and a relation to Op1?
if (const Relation *Op2R = Op0VI->requestRelation(Op1))
- Result = Op2R->getImpliedResult(Opcode);
+ Result = Op2R->getImpliedResult(predicate);
}
}
return Result;
// Relation Implementation
//===----------------------------------------------------------------------===//
-// CheckCondition - Return true if the specified condition is false. Bound may
-// be null.
-static bool CheckCondition(Constant *Bound, Constant *C,
- Instruction::BinaryOps BO) {
- assert(C != 0 && "C is not specified!");
- if (Bound == 0) return false;
-
- ConstantBool *Val;
- switch (BO) {
- default: assert(0 && "Unknown Condition code!");
- case Instruction::SetEQ: Val = *Bound == *C; break;
- case Instruction::SetNE: Val = *Bound != *C; break;
- case Instruction::SetLT: Val = *Bound < *C; break;
- case Instruction::SetGT: Val = *Bound > *C; break;
- case Instruction::SetLE: Val = *Bound <= *C; break;
- case Instruction::SetGE: Val = *Bound >= *C; break;
- }
-
- // ConstantHandling code may not succeed in the comparison...
- if (Val == 0) return false;
- return !Val->getValue(); // Return true if the condition is false...
-}
-
// contradicts - Return true if the relationship specified by the operand
// contradicts already known information.
//
-bool Relation::contradicts(Instruction::BinaryOps Op,
+bool Relation::contradicts(unsigned Op,
const ValueInfo &VI) const {
assert (Op != Instruction::Add && "Invalid relation argument!");
// does not contradict properties known about the bounds of the constant.
//
if (ConstantIntegral *C = dyn_cast<ConstantIntegral>(Val))
- if (ConstantRange(Op, C).intersectWith(VI.getBounds()).isEmptySet())
- return true;
+ if (Op >= ICmpInst::FIRST_ICMP_PREDICATE &&
+ Op <= ICmpInst::LAST_ICMP_PREDICATE)
+ if (ConstantRange(Op, C).intersectWith(VI.getBounds(),
+ ICmpInst::isSignedPredicate(ICmpInst::Predicate(Op))).isEmptySet())
+ return true;
switch (Rel) {
default: assert(0 && "Unknown Relationship code!");
case Instruction::Add: return false; // Nothing known, nothing contradicts
- case Instruction::SetEQ:
- return Op == Instruction::SetLT || Op == Instruction::SetGT ||
- Op == Instruction::SetNE;
- case Instruction::SetNE: return Op == Instruction::SetEQ;
- case Instruction::SetLE: return Op == Instruction::SetGT;
- case Instruction::SetGE: return Op == Instruction::SetLT;
- case Instruction::SetLT:
- return Op == Instruction::SetEQ || Op == Instruction::SetGT ||
- Op == Instruction::SetGE;
- case Instruction::SetGT:
- return Op == Instruction::SetEQ || Op == Instruction::SetLT ||
- Op == Instruction::SetLE;
+ case ICmpInst::ICMP_EQ:
+ return Op == ICmpInst::ICMP_ULT || Op == ICmpInst::ICMP_SLT ||
+ Op == ICmpInst::ICMP_UGT || Op == ICmpInst::ICMP_SGT ||
+ Op == ICmpInst::ICMP_NE;
+ case ICmpInst::ICMP_NE: return Op == ICmpInst::ICMP_EQ;
+ case ICmpInst::ICMP_ULE:
+ case ICmpInst::ICMP_SLE: return Op == ICmpInst::ICMP_UGT ||
+ Op == ICmpInst::ICMP_SGT;
+ case ICmpInst::ICMP_UGE:
+ case ICmpInst::ICMP_SGE: return Op == ICmpInst::ICMP_ULT ||
+ Op == ICmpInst::ICMP_SLT;
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_SLT:
+ return Op == ICmpInst::ICMP_EQ || Op == ICmpInst::ICMP_UGT ||
+ Op == ICmpInst::ICMP_SGT || Op == ICmpInst::ICMP_UGE ||
+ Op == ICmpInst::ICMP_SGE;
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_SGT:
+ return Op == ICmpInst::ICMP_EQ || Op == ICmpInst::ICMP_ULT ||
+ Op == ICmpInst::ICMP_SLT || Op == ICmpInst::ICMP_ULE ||
+ Op == ICmpInst::ICMP_SLE;
+ case FCmpInst::FCMP_OEQ:
+ return Op == FCmpInst::FCMP_OLT || Op == FCmpInst::FCMP_OGT ||
+ Op == FCmpInst::FCMP_ONE;
+ case FCmpInst::FCMP_ONE: return Op == FCmpInst::FCMP_OEQ;
+ case FCmpInst::FCMP_OLE: return Op == FCmpInst::FCMP_OGT;
+ case FCmpInst::FCMP_OGE: return Op == FCmpInst::FCMP_OLT;
+ case FCmpInst::FCMP_OLT:
+ return Op == FCmpInst::FCMP_OEQ || Op == FCmpInst::FCMP_OGT ||
+ Op == FCmpInst::FCMP_OGE;
+ case FCmpInst::FCMP_OGT:
+ return Op == FCmpInst::FCMP_OEQ || Op == FCmpInst::FCMP_OLT ||
+ Op == FCmpInst::FCMP_OLE;
}
}
// new information is gained, true is returned, otherwise false is returned to
// indicate that nothing was updated.
//
-bool Relation::incorporate(Instruction::BinaryOps Op, ValueInfo &VI) {
+bool Relation::incorporate(unsigned Op, ValueInfo &VI) {
assert(!contradicts(Op, VI) &&
"Cannot incorporate contradictory information!");
// range that is possible for the value to have...
//
if (ConstantIntegral *C = dyn_cast<ConstantIntegral>(Val))
- VI.getBounds() = ConstantRange(Op, C).intersectWith(VI.getBounds());
+ if (Op >= ICmpInst::FIRST_ICMP_PREDICATE &&
+ Op <= ICmpInst::LAST_ICMP_PREDICATE)
+ VI.getBounds() = ConstantRange(Op, C).intersectWith(VI.getBounds(),
+ ICmpInst::isSignedPredicate(ICmpInst::Predicate(Op)));
switch (Rel) {
default: assert(0 && "Unknown prior value!");
case Instruction::Add: Rel = Op; return true;
- case Instruction::SetEQ: return false; // Nothing is more precise
- case Instruction::SetNE: return false; // Nothing is more precise
- case Instruction::SetLT: return false; // Nothing is more precise
- case Instruction::SetGT: return false; // Nothing is more precise
- case Instruction::SetLE:
- if (Op == Instruction::SetEQ || Op == Instruction::SetLT) {
+ case ICmpInst::ICMP_EQ:
+ case ICmpInst::ICMP_NE:
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_SGT: return false; // Nothing is more precise
+ case ICmpInst::ICMP_ULE:
+ case ICmpInst::ICMP_SLE:
+ if (Op == ICmpInst::ICMP_EQ || Op == ICmpInst::ICMP_ULT ||
+ Op == ICmpInst::ICMP_SLT) {
+ Rel = Op;
+ return true;
+ } else if (Op == ICmpInst::ICMP_NE) {
+ Rel = Rel == ICmpInst::ICMP_ULE ? ICmpInst::ICMP_ULT :
+ ICmpInst::ICMP_SLT;
+ return true;
+ }
+ return false;
+ case ICmpInst::ICMP_UGE:
+ case ICmpInst::ICMP_SGE:
+ if (Op == ICmpInst::ICMP_EQ || ICmpInst::ICMP_UGT ||
+ Op == ICmpInst::ICMP_SGT) {
Rel = Op;
return true;
- } else if (Op == Instruction::SetNE) {
- Rel = Instruction::SetLT;
+ } else if (Op == ICmpInst::ICMP_NE) {
+ Rel = Rel == ICmpInst::ICMP_UGE ? ICmpInst::ICMP_UGT :
+ ICmpInst::ICMP_SGT;
return true;
}
return false;
- case Instruction::SetGE: return Op == Instruction::SetLT;
- if (Op == Instruction::SetEQ || Op == Instruction::SetGT) {
+ case FCmpInst::FCMP_OEQ: return false; // Nothing is more precise
+ case FCmpInst::FCMP_ONE: return false; // Nothing is more precise
+ case FCmpInst::FCMP_OLT: return false; // Nothing is more precise
+ case FCmpInst::FCMP_OGT: return false; // Nothing is more precise
+ case FCmpInst::FCMP_OLE:
+ if (Op == FCmpInst::FCMP_OEQ || Op == FCmpInst::FCMP_OLT) {
Rel = Op;
return true;
- } else if (Op == Instruction::SetNE) {
- Rel = Instruction::SetGT;
+ } else if (Op == FCmpInst::FCMP_ONE) {
+ Rel = FCmpInst::FCMP_OLT;
+ return true;
+ }
+ return false;
+ case FCmpInst::FCMP_OGE:
+ return Op == FCmpInst::FCMP_OLT;
+ if (Op == FCmpInst::FCMP_OEQ || Op == FCmpInst::FCMP_OGT) {
+ Rel = Op;
+ return true;
+ } else if (Op == FCmpInst::FCMP_ONE) {
+ Rel = FCmpInst::FCMP_OGT;
return true;
}
return false;
// determine the result required, return Unknown.
//
Relation::KnownResult
-Relation::getImpliedResult(Instruction::BinaryOps Op) const {
+Relation::getImpliedResult(unsigned Op) const {
if (Rel == Op) return KnownTrue;
- if (Rel == SetCondInst::getInverseCondition(Op)) return KnownFalse;
+ if (Op >= ICmpInst::FIRST_ICMP_PREDICATE &&
+ Op <= ICmpInst::LAST_ICMP_PREDICATE) {
+ if (Rel == unsigned(ICmpInst::getInversePredicate(ICmpInst::Predicate(Op))))
+ return KnownFalse;
+ } else if (Op <= FCmpInst::LAST_FCMP_PREDICATE) {
+ if (Rel == unsigned(FCmpInst::getInversePredicate(FCmpInst::Predicate(Op))))
+ return KnownFalse;
+ }
switch (Rel) {
default: assert(0 && "Unknown prior value!");
- case Instruction::SetEQ:
- if (Op == Instruction::SetLE || Op == Instruction::SetGE) return KnownTrue;
- if (Op == Instruction::SetLT || Op == Instruction::SetGT) return KnownFalse;
+ case ICmpInst::ICMP_EQ:
+ if (Op == ICmpInst::ICMP_ULE || Op == ICmpInst::ICMP_SLE ||
+ Op == ICmpInst::ICMP_UGE || Op == ICmpInst::ICMP_SGE) return KnownTrue;
+ if (Op == ICmpInst::ICMP_ULT || Op == ICmpInst::ICMP_SLT ||
+ Op == ICmpInst::ICMP_UGT || Op == ICmpInst::ICMP_SGT) return KnownFalse;
+ break;
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_SLT:
+ if (Op == ICmpInst::ICMP_ULE || Op == ICmpInst::ICMP_SLE ||
+ Op == ICmpInst::ICMP_NE) return KnownTrue;
+ if (Op == ICmpInst::ICMP_EQ) return KnownFalse;
+ break;
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_SGT:
+ if (Op == ICmpInst::ICMP_UGE || Op == ICmpInst::ICMP_SGE ||
+ Op == ICmpInst::ICMP_NE) return KnownTrue;
+ if (Op == ICmpInst::ICMP_EQ) return KnownFalse;
+ break;
+ case FCmpInst::FCMP_OEQ:
+ if (Op == FCmpInst::FCMP_OLE || Op == FCmpInst::FCMP_OGE) return KnownTrue;
+ if (Op == FCmpInst::FCMP_OLT || Op == FCmpInst::FCMP_OGT) return KnownFalse;
break;
- case Instruction::SetLT:
- if (Op == Instruction::SetNE || Op == Instruction::SetLE) return KnownTrue;
- if (Op == Instruction::SetEQ) return KnownFalse;
+ case FCmpInst::FCMP_OLT:
+ if (Op == FCmpInst::FCMP_ONE || Op == FCmpInst::FCMP_OLE) return KnownTrue;
+ if (Op == FCmpInst::FCMP_OEQ) return KnownFalse;
break;
- case Instruction::SetGT:
- if (Op == Instruction::SetNE || Op == Instruction::SetGE) return KnownTrue;
- if (Op == Instruction::SetEQ) return KnownFalse;
+ case FCmpInst::FCMP_OGT:
+ if (Op == FCmpInst::FCMP_ONE || Op == FCmpInst::FCMP_OGE) return KnownTrue;
+ if (Op == FCmpInst::FCMP_OEQ) return KnownFalse;
break;
- case Instruction::SetNE:
- case Instruction::SetLE:
- case Instruction::SetGE:
- case Instruction::Add:
+ case ICmpInst::ICMP_NE:
+ case ICmpInst::ICMP_SLE:
+ case ICmpInst::ICMP_ULE:
+ case ICmpInst::ICMP_UGE:
+ case ICmpInst::ICMP_SGE:
+ case FCmpInst::FCMP_ONE:
+ case FCmpInst::FCMP_OLE:
+ case FCmpInst::FCMP_OGE:
+ case FCmpInst::FCMP_FALSE:
+ case FCmpInst::FCMP_ORD:
+ case FCmpInst::FCMP_UNO:
+ case FCmpInst::FCMP_UEQ:
+ case FCmpInst::FCMP_UGT:
+ case FCmpInst::FCMP_UGE:
+ case FCmpInst::FCMP_ULT:
+ case FCmpInst::FCMP_ULE:
+ case FCmpInst::FCMP_UNE:
+ case FCmpInst::FCMP_TRUE:
break;
}
return Unknown;
// print - Implement the standard print form to print out analysis information.
void CEE::print(std::ostream &O, const Module *M) const {
O << "\nPrinting Correlated Expression Info:\n";
- for (std::map<BasicBlock*, RegionInfo>::const_iterator I =
+ for (std::map<BasicBlock*, RegionInfo>::const_iterator I =
RegionInfoMap.begin(), E = RegionInfoMap.end(); I != E; ++I)
I->second.print(O);
}
OS << " is ";
switch (Rel) {
default: OS << "*UNKNOWN*"; break;
- case Instruction::SetEQ: OS << "== "; break;
- case Instruction::SetNE: OS << "!= "; break;
- case Instruction::SetLT: OS << "< "; break;
- case Instruction::SetGT: OS << "> "; break;
- case Instruction::SetLE: OS << "<= "; break;
- case Instruction::SetGE: OS << ">= "; break;
+ case ICmpInst::ICMP_EQ:
+ case FCmpInst::FCMP_ORD:
+ case FCmpInst::FCMP_UEQ:
+ case FCmpInst::FCMP_OEQ: OS << "== "; break;
+ case ICmpInst::ICMP_NE:
+ case FCmpInst::FCMP_UNO:
+ case FCmpInst::FCMP_UNE:
+ case FCmpInst::FCMP_ONE: OS << "!= "; break;
+ case ICmpInst::ICMP_ULT:
+ case ICmpInst::ICMP_SLT:
+ case FCmpInst::FCMP_ULT:
+ case FCmpInst::FCMP_OLT: OS << "< "; break;
+ case ICmpInst::ICMP_UGT:
+ case ICmpInst::ICMP_SGT:
+ case FCmpInst::FCMP_UGT:
+ case FCmpInst::FCMP_OGT: OS << "> "; break;
+ case ICmpInst::ICMP_ULE:
+ case ICmpInst::ICMP_SLE:
+ case FCmpInst::FCMP_ULE:
+ case FCmpInst::FCMP_OLE: OS << "<= "; break;
+ case ICmpInst::ICMP_UGE:
+ case ICmpInst::ICMP_SGE:
+ case FCmpInst::FCMP_UGE:
+ case FCmpInst::FCMP_OGE: OS << ">= "; break;
}
WriteAsOperand(OS, Val);
OS << "\n";
}
-void Relation::dump() const { print(std::cerr); }
-void ValueInfo::dump() const { print(std::cerr, 0); }
+// Don't inline these methods or else we won't be able to call them from GDB!
+void Relation::dump() const { print(*cerr.stream()); }
+void ValueInfo::dump() const { print(*cerr.stream(), 0); }
+void RegionInfo::dump() const { print(*cerr.stream()); }
projects / oota-llvm.git / blobdiff