Remove use of ETForest. Also cleaned up issues around unreachable basic

blocks, and optimizing within one basic block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37709 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nick Lewycky 2007-06-24 04:36:20 +00:00
parent 647580483c
commit 984504b912

View File

@ -92,7 +92,6 @@
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/ET-Forest.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ConstantRange.h"
@ -103,6 +102,7 @@
#include <algorithm>
#include <deque>
#include <sstream>
#include <stack>
using namespace llvm;
STATISTIC(NumVarsReplaced, "Number of argument substitutions");
@ -112,6 +112,186 @@ STATISTIC(NumBlocks , "Number of blocks marked unreachable");
STATISTIC(NumSnuggle , "Number of comparisons snuggled");
namespace {
class DomTreeDFS {
public:
class Node {
friend class DomTreeDFS;
public:
typedef std::vector<Node *>::iterator iterator;
typedef std::vector<Node *>::const_iterator const_iterator;
unsigned getDFSNumIn() const { return DFSin; }
unsigned getDFSNumOut() const { return DFSout; }
BasicBlock *getBlock() const { return BB; }
iterator begin() { return Children.begin(); }
iterator end() { return Children.end(); }
const_iterator begin() const { return Children.begin(); }
const_iterator end() const { return Children.end(); }
bool dominates(const Node *N) const {
return DFSin <= N->DFSin && DFSout >= N->DFSout;
}
bool DominatedBy(const Node *N) const {
return N->dominates(this);
}
/// Sorts by the number of descendants. With this, you can iterate
/// through a sorted list and the first matching entry is the most
/// specific match for your basic block. The order provided is stable;
/// DomTreeDFS::Nodes with the same number of descendants are sorted by
/// DFS in number.
bool operator<(const Node &N) const {
unsigned spread = DFSout - DFSin;
unsigned N_spread = N.DFSout - N.DFSin;
if (spread == N_spread) return DFSin < N.DFSin;
else return DFSout - DFSin < N.DFSout - N.DFSin;
}
bool operator>(const Node &N) const { return N < *this; }
private:
unsigned DFSin, DFSout;
BasicBlock *BB;
std::vector<Node *> Children;
};
// XXX: this may be slow. Instead of using "new" for each node, consider
// putting them in a vector to keep them contiguous.
explicit DomTreeDFS(DominatorTree *DT) {
std::stack<std::pair<Node *, DomTreeNode *> > S;
Entry = new Node;
Entry->BB = DT->getRootNode()->getBlock();
S.push(std::make_pair(Entry, DT->getRootNode()));
NodeMap[Entry->BB] = Entry;
while (!S.empty()) {
std::pair<Node *, DomTreeNode *> &Pair = S.top();
Node *N = Pair.first;
DomTreeNode *DTNode = Pair.second;
S.pop();
for (DomTreeNode::iterator I = DTNode->begin(), E = DTNode->end();
I != E; ++I) {
Node *NewNode = new Node;
NewNode->BB = (*I)->getBlock();
N->Children.push_back(NewNode);
S.push(std::make_pair(NewNode, *I));
NodeMap[NewNode->BB] = NewNode;
}
}
renumber();
#ifndef NDEBUG
DEBUG(dump());
#endif
}
#ifndef NDEBUG
virtual
#endif
~DomTreeDFS() {
std::stack<Node *> S;
S.push(Entry);
while (!S.empty()) {
Node *N = S.top(); S.pop();
for (Node::iterator I = N->begin(), E = N->end(); I != E; ++I)
S.push(*I);
delete N;
}
}
Node *getRootNode() const { return Entry; }
Node *getNodeForBlock(BasicBlock *BB) const {
if (!NodeMap.count(BB)) return 0;
else return const_cast<DomTreeDFS*>(this)->NodeMap[BB];
}
bool dominates(Instruction *I1, Instruction *I2) {
BasicBlock *BB1 = I1->getParent(),
*BB2 = I2->getParent();
if (BB1 == BB2) {
if (isa<TerminatorInst>(I1)) return false;
if (isa<TerminatorInst>(I2)) return true;
if ( isa<PHINode>(I1) && !isa<PHINode>(I2)) return true;
if (!isa<PHINode>(I1) && isa<PHINode>(I2)) return false;
for (BasicBlock::const_iterator I = BB2->begin(), E = BB2->end();
I != E; ++I) {
if (&*I == I1) return true;
else if (&*I == I2) return false;
}
assert(!"Instructions not found in parent BasicBlock?");
} else {
Node *Node1 = getNodeForBlock(BB1),
*Node2 = getNodeForBlock(BB2);
if (!Node1 || !Node2) return false;
return Node1->dominates(Node2);
}
}
private:
void renumber() {
std::stack<std::pair<Node *, Node::iterator> > S;
unsigned n = 0;
Entry->DFSin = ++n;
S.push(std::make_pair(Entry, Entry->begin()));
while (!S.empty()) {
std::pair<Node *, Node::iterator> &Pair = S.top();
Node *N = Pair.first;
Node::iterator &I = Pair.second;
if (I == N->end()) {
N->DFSout = ++n;
S.pop();
} else {
Node *Next = *I++;
Next->DFSin = ++n;
S.push(std::make_pair(Next, Next->begin()));
}
}
}
#ifndef NDEBUG
virtual void dump() const {
dump(*cerr.stream());
}
void dump(std::ostream &os) const {
os << "Predicate simplifier DomTreeDFS: \n";
dump(Entry, 0, os);
os << "\n\n";
}
void dump(Node *N, int depth, std::ostream &os) const {
++depth;
for (int i = 0; i < depth; ++i) { os << " "; }
os << "[" << depth << "] ";
os << N->getBlock()->getName() << " (" << N->getDFSNumIn()
<< ", " << N->getDFSNumOut() << ")\n";
for (Node::iterator I = N->begin(), E = N->end(); I != E; ++I)
dump(*I, depth, os);
}
#endif
Node *Entry;
std::map<BasicBlock *, Node *> NodeMap;
};
// SLT SGT ULT UGT EQ
// 0 1 0 1 0 -- GT 10
// 0 1 0 1 1 -- GE 11
@ -181,20 +361,6 @@ namespace {
return Rev;
}
/// This is a StrictWeakOrdering predicate that sorts ETNodes by how many
/// descendants they have. With this, you can iterate through a list sorted
/// by this operation and the first matching entry is the most specific
/// match for your basic block. The order provided is stable; ETNodes with
/// the same number of children are sorted by pointer address.
struct VISIBILITY_HIDDEN OrderByDominance {
bool operator()(const ETNode *LHS, const ETNode *RHS) const {
unsigned LHS_spread = LHS->getDFSNumOut() - LHS->getDFSNumIn();
unsigned RHS_spread = RHS->getDFSNumOut() - RHS->getDFSNumIn();
if (LHS_spread != RHS_spread) return LHS_spread < RHS_spread;
else return LHS < RHS;
}
};
/// The InequalityGraph stores the relationships between values.
/// Each Value in the graph is assigned to a Node. Nodes are pointer
/// comparable for equality. The caller is expected to maintain the logical
@ -203,35 +369,37 @@ namespace {
/// The InequalityGraph class may invalidate Node*s after any mutator call.
/// @brief The InequalityGraph stores the relationships between values.
class VISIBILITY_HIDDEN InequalityGraph {
ETNode *TreeRoot;
DomTreeDFS::Node *TreeRoot;
InequalityGraph(); // DO NOT IMPLEMENT
InequalityGraph(InequalityGraph &); // DO NOT IMPLEMENT
public:
explicit InequalityGraph(ETNode *TreeRoot) : TreeRoot(TreeRoot) {}
explicit InequalityGraph(DomTreeDFS::Node *TreeRoot) : TreeRoot(TreeRoot){}
class Node;
/// An Edge is contained inside a Node making one end of the edge implicit
/// and contains a pointer to the other end. The edge contains a lattice
/// value specifying the relationship and an ETNode specifying the root
/// in the dominator tree to which this edge applies.
/// value specifying the relationship and an DomTreeDFS::Node specifying
/// the root in the dominator tree to which this edge applies.
class VISIBILITY_HIDDEN Edge {
public:
Edge(unsigned T, LatticeVal V, ETNode *ST)
Edge(unsigned T, LatticeVal V, DomTreeDFS::Node *ST)
: To(T), LV(V), Subtree(ST) {}
unsigned To;
LatticeVal LV;
ETNode *Subtree;
DomTreeDFS::Node *Subtree;
bool operator<(const Edge &edge) const {
if (To != edge.To) return To < edge.To;
else return OrderByDominance()(Subtree, edge.Subtree);
else return *Subtree < *edge.Subtree;
}
bool operator<(unsigned to) const {
return To < to;
}
bool operator>(unsigned to) const {
return To > to;
}
@ -293,7 +461,7 @@ namespace {
const_iterator begin() const { return Relations.begin(); }
const_iterator end() const { return Relations.end(); }
iterator find(unsigned n, ETNode *Subtree) {
iterator find(unsigned n, DomTreeDFS::Node *Subtree) {
iterator E = end();
for (iterator I = std::lower_bound(begin(), E, n);
I != E && I->To == n; ++I) {
@ -303,7 +471,7 @@ namespace {
return E;
}
const_iterator find(unsigned n, ETNode *Subtree) const {
const_iterator find(unsigned n, DomTreeDFS::Node *Subtree) const {
const_iterator E = end();
for (const_iterator I = std::lower_bound(begin(), E, n);
I != E && I->To == n; ++I) {
@ -321,7 +489,7 @@ namespace {
/// Updates the lattice value for a given node. Create a new entry if
/// one doesn't exist, otherwise it merges the values. The new lattice
/// value must not be inconsistent with any previously existing value.
void update(unsigned n, LatticeVal R, ETNode *Subtree) {
void update(unsigned n, LatticeVal R, DomTreeDFS::Node *Subtree) {
assert(validPredicate(R) && "Invalid predicate.");
iterator I = find(n, Subtree);
if (I == end()) {
@ -360,9 +528,9 @@ namespace {
struct VISIBILITY_HIDDEN NodeMapEdge {
Value *V;
unsigned index;
ETNode *Subtree;
DomTreeDFS::Node *Subtree;
NodeMapEdge(Value *V, unsigned index, ETNode *Subtree)
NodeMapEdge(Value *V, unsigned index, DomTreeDFS::Node *Subtree)
: V(V), index(index), Subtree(Subtree) {}
bool operator==(const NodeMapEdge &RHS) const {
@ -372,7 +540,7 @@ namespace {
bool operator<(const NodeMapEdge &RHS) const {
if (V != RHS.V) return V < RHS.V;
return OrderByDominance()(Subtree, RHS.Subtree);
else return *Subtree < *RHS.Subtree;
}
bool operator<(Value *RHS) const {
@ -397,7 +565,7 @@ namespace {
/// Returns the node currently representing Value V, or zero if no such
/// node exists.
unsigned getNode(Value *V, ETNode *Subtree) {
unsigned getNode(Value *V, DomTreeDFS::Node *Subtree) {
NodeMapType::iterator E = NodeMap.end();
NodeMapEdge Edge(V, 0, Subtree);
NodeMapType::iterator I = std::lower_bound(NodeMap.begin(), E, Edge);
@ -411,7 +579,7 @@ namespace {
/// getOrInsertNode - always returns a valid node index, creating a node
/// to match the Value if needed.
unsigned getOrInsertNode(Value *V, ETNode *Subtree) {
unsigned getOrInsertNode(Value *V, DomTreeDFS::Node *Subtree) {
if (unsigned n = getNode(V, Subtree))
return n;
else
@ -420,6 +588,9 @@ namespace {
/// newNode - creates a new node for a given Value and returns the index.
unsigned newNode(Value *V) {
assert(!isa<BasicBlock>(V) && "BBs may not be nodes.");
assert(V->getType() != Type::VoidTy && "Void node?");
Nodes.push_back(Node(V));
NodeMapEdge MapEntry = NodeMapEdge(V, Nodes.size(), TreeRoot);
@ -432,7 +603,7 @@ namespace {
/// If the Value is in the graph, return the canonical form. Otherwise,
/// return the original Value.
Value *canonicalize(Value *V, ETNode *Subtree) {
Value *canonicalize(Value *V, DomTreeDFS::Node *Subtree) {
if (isa<Constant>(V)) return V;
if (unsigned n = getNode(V, Subtree))
@ -442,7 +613,8 @@ namespace {
}
/// isRelatedBy - true iff n1 op n2
bool isRelatedBy(unsigned n1, unsigned n2, ETNode *Subtree, LatticeVal LV) {
bool isRelatedBy(unsigned n1, unsigned n2, DomTreeDFS::Node *Subtree,
LatticeVal LV) {
if (n1 == n2) return LV & EQ_BIT;
Node *N1 = node(n1);
@ -455,7 +627,7 @@ namespace {
// The add* methods assume that your input is logically valid and may
// assertion-fail or infinitely loop if you attempt a contradiction.
void addEquality(unsigned n, Value *V, ETNode *Subtree) {
void addEquality(unsigned n, Value *V, DomTreeDFS::Node *Subtree) {
assert(canonicalize(node(n)->getValue(), Subtree) == node(n)->getValue()
&& "Node's 'canonical' choice isn't best within this subtree.");
@ -504,7 +676,7 @@ namespace {
/// addInequality - Sets n1 op n2.
/// It is also an error to call this on an inequality that is already true.
void addInequality(unsigned n1, unsigned n2, ETNode *Subtree,
void addInequality(unsigned n1, unsigned n2, DomTreeDFS::Node *Subtree,
LatticeVal LV1) {
assert(n1 != n2 && "A node can't be inequal to itself.");
@ -529,7 +701,7 @@ namespace {
for (Node::iterator I = N1->begin(), E = N1->end(); I != E; ++I) {
if (I->LV != NE && I->To != n2) {
ETNode *Local_Subtree = NULL;
DomTreeDFS::Node *Local_Subtree = NULL;
if (Subtree->DominatedBy(I->Subtree))
Local_Subtree = Subtree;
else if (I->Subtree->DominatedBy(Subtree))
@ -565,7 +737,7 @@ namespace {
for (Node::iterator I = N2->begin(), E = N2->end(); I != E; ++I) {
if (I->LV != NE && I->To != n1) {
ETNode *Local_Subtree = NULL;
DomTreeDFS::Node *Local_Subtree = NULL;
if (Subtree->DominatedBy(I->Subtree))
Local_Subtree = Subtree;
else if (I->Subtree->DominatedBy(Subtree))
@ -661,16 +833,16 @@ namespace {
/// the scope of a rooted subtree in the dominator tree.
class VISIBILITY_HIDDEN ScopedRange {
public:
ScopedRange(Value *V, ConstantRange CR, ETNode *ST)
ScopedRange(Value *V, ConstantRange CR, DomTreeDFS::Node *ST)
: V(V), CR(CR), Subtree(ST) {}
Value *V;
ConstantRange CR;
ETNode *Subtree;
DomTreeDFS::Node *Subtree;
bool operator<(const ScopedRange &range) const {
if (V != range.V) return V < range.V;
else return OrderByDominance()(Subtree, range.Subtree);
else return Subtree < range.Subtree;
}
bool operator<(const Value *value) const {
@ -697,7 +869,7 @@ namespace {
iterator begin() { return Ranges.begin(); }
iterator end() { return Ranges.end(); }
iterator find(Value *V, ETNode *Subtree) {
iterator find(Value *V, DomTreeDFS::Node *Subtree) {
iterator E = end();
for (iterator I = std::lower_bound(begin(), E, V);
I != E && I->V == V; ++I) {
@ -707,7 +879,7 @@ namespace {
return E;
}
void update(Value *V, ConstantRange CR, ETNode *Subtree) {
void update(Value *V, ConstantRange CR, DomTreeDFS::Node *Subtree) {
assert(!CR.isEmptySet() && "Empty ConstantRange!");
if (CR.isFullSet()) return;
@ -827,7 +999,7 @@ namespace {
}
#ifndef NDEBUG
bool isCanonical(Value *V, ETNode *Subtree, VRPSolver *VRP);
bool isCanonical(Value *V, DomTreeDFS::Node *Subtree, VRPSolver *VRP);
#endif
public:
@ -838,7 +1010,8 @@ namespace {
// constant it constructs the single element range, otherwise it performs
// a lookup. The width W must be retrieved from typeToWidth and may not
// be zero.
ConstantRange rangeFromValue(Value *V, ETNode *Subtree, uint32_t W) {
ConstantRange rangeFromValue(Value *V, DomTreeDFS::Node *Subtree,
uint32_t W) {
if (ConstantInt *C = dyn_cast<ConstantInt>(V)) {
return ConstantRange(C->getValue());
} else if (isa<ConstantPointerNull>(V)) {
@ -863,7 +1036,8 @@ namespace {
return 0;
}
bool isRelatedBy(Value *V1, Value *V2, ETNode *Subtree, LatticeVal LV) {
bool isRelatedBy(Value *V1, Value *V2, DomTreeDFS::Node *Subtree,
LatticeVal LV) {
uint32_t W = typeToWidth(V1->getType());
if (!W) return false;
@ -922,8 +1096,8 @@ namespace {
VRPSolver *VRP);
void markBlock(VRPSolver *VRP);
void mergeInto(Value **I, unsigned n, Value *New, ETNode *Subtree,
VRPSolver *VRP) {
void mergeInto(Value **I, unsigned n, Value *New,
DomTreeDFS::Node *Subtree, VRPSolver *VRP) {
assert(isCanonical(New, Subtree, VRP) && "Best choice not canonical?");
uint32_t W = typeToWidth(New->getType());
@ -943,8 +1117,8 @@ namespace {
applyRange(New, Merged, Subtree, VRP);
}
void applyRange(Value *V, const ConstantRange &CR, ETNode *Subtree,
VRPSolver *VRP) {
void applyRange(Value *V, const ConstantRange &CR,
DomTreeDFS::Node *Subtree, VRPSolver *VRP) {
assert(isCanonical(V, Subtree, VRP) && "Value not canonical.");
if (const APInt *I = CR.getSingleElement()) {
@ -970,7 +1144,8 @@ namespace {
update(V, Merged, Subtree);
}
void addNotEquals(Value *V1, Value *V2, ETNode *Subtree, VRPSolver *VRP) {
void addNotEquals(Value *V1, Value *V2, DomTreeDFS::Node *Subtree,
VRPSolver *VRP) {
uint32_t W = typeToWidth(V1->getType());
if (!W) return;
@ -1024,8 +1199,8 @@ namespace {
}
}
void addInequality(Value *V1, Value *V2, ETNode *Subtree, LatticeVal LV,
VRPSolver *VRP) {
void addInequality(Value *V1, Value *V2, DomTreeDFS::Node *Subtree,
LatticeVal LV, VRPSolver *VRP) {
assert(!isRelatedBy(V1, V2, Subtree, LV) && "Asked to do useless work.");
assert(isCanonical(V1, Subtree, VRP) && "Value not canonical.");
@ -1123,7 +1298,7 @@ namespace {
Value *LHS, *RHS;
ICmpInst::Predicate Op;
BasicBlock *ContextBB;
BasicBlock *ContextBB; // XXX use a DomTreeDFS::Node instead
Instruction *ContextInst;
};
std::deque<Operation> WorkList;
@ -1131,37 +1306,14 @@ namespace {
InequalityGraph &IG;
UnreachableBlocks &UB;
ValueRanges &VR;
ETForest *Forest;
ETNode *Top;
DomTreeDFS *DTDFS;
DomTreeDFS::Node *Top;
BasicBlock *TopBB;
Instruction *TopInst;
bool &modified;
typedef InequalityGraph::Node Node;
/// IdomI - Determines whether one Instruction dominates another.
bool IdomI(Instruction *I1, Instruction *I2) const {
BasicBlock *BB1 = I1->getParent(),
*BB2 = I2->getParent();
if (BB1 == BB2) {
if (isa<TerminatorInst>(I1)) return false;
if (isa<TerminatorInst>(I2)) return true;
if (isa<PHINode>(I1) && !isa<PHINode>(I2)) return true;
if (!isa<PHINode>(I1) && isa<PHINode>(I2)) return false;
for (BasicBlock::const_iterator I = BB1->begin(), E = BB1->end();
I != E; ++I) {
if (&*I == I1) return true;
if (&*I == I2) return false;
}
assert(!"Instructions not found in parent BasicBlock?");
} else {
return Forest->properlyDominates(BB1, BB2);
}
return false;
}
/// Returns true if V1 is a better canonical value than V2.
bool compare(Value *V1, Value *V2) const {
if (isa<Constant>(V1))
@ -1179,22 +1331,48 @@ namespace {
if (!I1 || !I2)
return V1->getNumUses() < V2->getNumUses();
return IdomI(I1, I2);
return DTDFS->dominates(I1, I2);
}
// below - true if the Instruction is dominated by the current context
// block or instruction
bool below(Instruction *I) {
if (TopInst)
return IdomI(TopInst, I);
else {
ETNode *Node = Forest->getNodeForBlock(I->getParent());
return Node->DominatedBy(Top);
BasicBlock *BB = I->getParent();
if (TopInst && TopInst->getParent() == BB) {
if (isa<TerminatorInst>(TopInst)) return false;
if (isa<TerminatorInst>(I)) return true;
if ( isa<PHINode>(TopInst) && !isa<PHINode>(I)) return true;
if (!isa<PHINode>(TopInst) && isa<PHINode>(I)) return false;
for (BasicBlock::const_iterator Iter = BB->begin(), E = BB->end();
Iter != E; ++Iter) {
if (&*Iter == TopInst) return true;
else if (&*Iter == I) return false;
}
assert(!"Instructions not found in parent BasicBlock?");
} else {
DomTreeDFS::Node *Node = DTDFS->getNodeForBlock(BB);
if (!Node) return false;
return Top->dominates(Node);
}
}
// aboveOrBelow - true if the Instruction either dominates or is dominated
// by the current context block or instruction
bool aboveOrBelow(Instruction *I) {
BasicBlock *BB = I->getParent();
DomTreeDFS::Node *Node = DTDFS->getNodeForBlock(BB);
if (!Node) return false;
return Top == Node || Top->dominates(Node) || Node->dominates(Top);
}
bool makeEqual(Value *V1, Value *V2) {
DOUT << "makeEqual(" << *V1 << ", " << *V2 << ")\n";
DOUT << "context is ";
if (TopInst) DOUT << "I: " << *TopInst << "\n";
else DOUT << "BB: " << TopBB->getName()
<< "(" << Top->getDFSNumIn() << ")\n";
assert(V1->getType() == V2->getType() &&
"Can't make two values with different types equal.");
@ -1396,8 +1574,7 @@ namespace {
if (i) R = IG.node(Remove[i])->getValue(); // skip n2.
if (Instruction *I2 = dyn_cast<Instruction>(R)) {
if (below(I2) ||
Top->DominatedBy(Forest->getNodeForBlock(I2->getParent())))
if (aboveOrBelow(I2))
defToOps(I2);
}
for (Value::use_iterator UI = V2->use_begin(), UE = V2->use_end();
@ -1405,8 +1582,7 @@ namespace {
Use &TheUse = UI.getUse();
++UI;
if (Instruction *I = dyn_cast<Instruction>(TheUse.getUser())) {
if (below(I) ||
Top->DominatedBy(Forest->getNodeForBlock(I->getParent())))
if (aboveOrBelow(I))
opsToDef(I);
}
}
@ -1422,8 +1598,7 @@ namespace {
Value *V = TheUse.getUser();
if (!V->use_empty()) {
if (Instruction *Inst = dyn_cast<Instruction>(V)) {
if (below(Inst) ||
Top->DominatedBy(Forest->getNodeForBlock(Inst->getParent())))
if (aboveOrBelow(Inst))
opsToDef(Inst);
}
}
@ -1465,27 +1640,32 @@ namespace {
public:
VRPSolver(InequalityGraph &IG, UnreachableBlocks &UB, ValueRanges &VR,
ETForest *Forest, bool &modified, BasicBlock *TopBB)
DomTreeDFS *DTDFS, bool &modified, BasicBlock *TopBB)
: IG(IG),
UB(UB),
VR(VR),
Forest(Forest),
Top(Forest->getNodeForBlock(TopBB)),
DTDFS(DTDFS),
Top(DTDFS->getNodeForBlock(TopBB)),
TopBB(TopBB),
TopInst(NULL),
modified(modified) {}
modified(modified)
{
assert(Top && "VRPSolver created for unreachable basic block.");
}
VRPSolver(InequalityGraph &IG, UnreachableBlocks &UB, ValueRanges &VR,
ETForest *Forest, bool &modified, Instruction *TopInst)
DomTreeDFS *DTDFS, bool &modified, Instruction *TopInst)
: IG(IG),
UB(UB),
VR(VR),
Forest(Forest),
DTDFS(DTDFS),
Top(DTDFS->getNodeForBlock(TopInst->getParent())),
TopBB(TopInst->getParent()),
TopInst(TopInst),
modified(modified)
{
TopBB = TopInst->getParent();
Top = Forest->getNodeForBlock(TopBB);
assert(Top && "VRPSolver created for unreachable basic block.");
assert(Top->getBlock() == TopInst->getParent() && "Context mismatch.");
}
bool isRelatedBy(Value *V1, Value *V2, ICmpInst::Predicate Pred) const {
@ -1514,7 +1694,7 @@ namespace {
Instruction *I = NULL) {
DOUT << "adding " << *V1 << " " << Pred << " " << *V2;
if (I) DOUT << " context: " << *I;
else DOUT << " default context";
else DOUT << " default context (" << Top->getDFSNumIn() << ")";
DOUT << "\n";
assert(V1->getType() == V2->getType() &&
@ -1856,7 +2036,7 @@ namespace {
Operation &O = WorkList.front();
TopInst = O.ContextInst;
TopBB = O.ContextBB;
Top = Forest->getNodeForBlock(TopBB);
Top = DTDFS->getNodeForBlock(TopBB); // XXX move this into Context
O.LHS = IG.canonicalize(O.LHS, Top);
O.RHS = IG.canonicalize(O.RHS, Top);
@ -1933,8 +2113,7 @@ namespace {
}
if (Instruction *I1 = dyn_cast<Instruction>(O.LHS)) {
if (below(I1) ||
Top->DominatedBy(Forest->getNodeForBlock(I1->getParent())))
if (aboveOrBelow(I1))
defToOps(I1);
}
if (isa<Instruction>(O.LHS) || isa<Argument>(O.LHS)) {
@ -1943,15 +2122,13 @@ namespace {
Use &TheUse = UI.getUse();
++UI;
if (Instruction *I = dyn_cast<Instruction>(TheUse.getUser())) {
if (below(I) ||
Top->DominatedBy(Forest->getNodeForBlock(I->getParent())))
if (aboveOrBelow(I))
opsToDef(I);
}
}
}
if (Instruction *I2 = dyn_cast<Instruction>(O.RHS)) {
if (below(I2) ||
Top->DominatedBy(Forest->getNodeForBlock(I2->getParent())))
if (aboveOrBelow(I2))
defToOps(I2);
}
if (isa<Instruction>(O.RHS) || isa<Argument>(O.RHS)) {
@ -1960,9 +2137,7 @@ namespace {
Use &TheUse = UI.getUse();
++UI;
if (Instruction *I = dyn_cast<Instruction>(TheUse.getUser())) {
if (below(I) ||
Top->DominatedBy(Forest->getNodeForBlock(I->getParent())))
if (aboveOrBelow(I))
opsToDef(I);
}
}
@ -1984,7 +2159,8 @@ namespace {
}
#ifndef NDEBUG
bool ValueRanges::isCanonical(Value *V, ETNode *Subtree, VRPSolver *VRP) {
bool ValueRanges::isCanonical(Value *V, DomTreeDFS::Node *Subtree,
VRPSolver *VRP) {
return V == VRP->IG.canonicalize(V, Subtree);
}
#endif
@ -1994,14 +2170,13 @@ namespace {
/// can't be equal and will solve setcc instructions when possible.
/// @brief Root of the predicate simplifier optimization.
class VISIBILITY_HIDDEN PredicateSimplifier : public FunctionPass {
DominatorTree *DT;
ETForest *Forest;
DomTreeDFS *DTDFS;
bool modified;
InequalityGraph *IG;
UnreachableBlocks UB;
ValueRanges *VR;
std::vector<DomTreeNode *> WorkList;
std::vector<DomTreeDFS::Node *> WorkList;
public:
static char ID; // Pass identification, replacement for typeid
@ -2012,7 +2187,6 @@ namespace {
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequiredID(BreakCriticalEdgesID);
AU.addRequired<DominatorTree>();
AU.addRequired<ETForest>();
AU.addRequired<TargetData>();
AU.addPreserved<TargetData>();
}
@ -2027,14 +2201,14 @@ namespace {
class VISIBILITY_HIDDEN Forwards : public InstVisitor<Forwards> {
friend class InstVisitor<Forwards>;
PredicateSimplifier *PS;
DomTreeNode *DTNode;
DomTreeDFS::Node *DTNode;
public:
InequalityGraph &IG;
UnreachableBlocks &UB;
ValueRanges &VR;
Forwards(PredicateSimplifier *PS, DomTreeNode *DTNode)
Forwards(PredicateSimplifier *PS, DomTreeDFS::Node *DTNode)
: PS(PS), DTNode(DTNode), IG(*PS->IG), UB(PS->UB), VR(*PS->VR) {}
void visitTerminatorInst(TerminatorInst &TI);
@ -2055,31 +2229,30 @@ namespace {
// Used by terminator instructions to proceed from the current basic
// block to the next. Verifies that "current" dominates "next",
// then calls visitBasicBlock.
void proceedToSuccessors(DomTreeNode *Current) {
for (DomTreeNode::iterator I = Current->begin(),
void proceedToSuccessors(DomTreeDFS::Node *Current) {
for (DomTreeDFS::Node::iterator I = Current->begin(),
E = Current->end(); I != E; ++I) {
WorkList.push_back(*I);
}
}
void proceedToSuccessor(DomTreeNode *Next) {
void proceedToSuccessor(DomTreeDFS::Node *Next) {
WorkList.push_back(Next);
}
// Visits each instruction in the basic block.
void visitBasicBlock(DomTreeNode *Node) {
void visitBasicBlock(DomTreeDFS::Node *Node) {
BasicBlock *BB = Node->getBlock();
ETNode *ET = Forest->getNodeForBlock(BB);
DOUT << "Entering Basic Block: " << BB->getName()
<< " (" << ET->getDFSNumIn() << ")\n";
<< " (" << Node->getDFSNumIn() << ")\n";
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;) {
visitInstruction(I++, Node, ET);
visitInstruction(I++, Node);
}
}
// Tries to simplify each Instruction and add new properties to
// the PropertySet.
void visitInstruction(Instruction *I, DomTreeNode *DT, ETNode *ET) {
void visitInstruction(Instruction *I, DomTreeDFS::Node *DT) {
DOUT << "Considering instruction " << *I << "\n";
DEBUG(IG->dump());
@ -2094,7 +2267,7 @@ namespace {
#ifndef NDEBUG
// Try to replace the whole instruction.
Value *V = IG->canonicalize(I, ET);
Value *V = IG->canonicalize(I, DT);
assert(V == I && "Late instruction canonicalization.");
if (V != I) {
modified = true;
@ -2109,7 +2282,7 @@ namespace {
// Try to substitute operands.
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
Value *Oper = I->getOperand(i);
Value *V = IG->canonicalize(Oper, ET);
Value *V = IG->canonicalize(Oper, DT);
assert(V == Oper && "Late operand canonicalization.");
if (V != Oper) {
modified = true;
@ -2130,28 +2303,25 @@ namespace {
};
bool PredicateSimplifier::runOnFunction(Function &F) {
DT = &getAnalysis<DominatorTree>();
Forest = &getAnalysis<ETForest>();
DominatorTree *DT = &getAnalysis<DominatorTree>();
DTDFS = new DomTreeDFS(DT);
TargetData *TD = &getAnalysis<TargetData>();
// XXX: should only act when numbers are out of date
Forest->updateDFSNumbers();
DOUT << "Entering Function: " << F.getName() << "\n";
modified = false;
BasicBlock *RootBlock = &F.getEntryBlock();
IG = new InequalityGraph(Forest->getNodeForBlock(RootBlock));
DomTreeDFS::Node *Root = DTDFS->getRootNode();
IG = new InequalityGraph(Root);
VR = new ValueRanges(TD);
WorkList.push_back(DT->getRootNode());
WorkList.push_back(Root);
do {
DomTreeNode *DTNode = WorkList.back();
DomTreeDFS::Node *DTNode = WorkList.back();
WorkList.pop_back();
if (!UB.isDead(DTNode->getBlock())) visitBasicBlock(DTNode);
} while (!WorkList.empty());
delete DTDFS;
delete VR;
delete IG;
@ -2179,21 +2349,21 @@ namespace {
return;
}
for (DomTreeNode::iterator I = DTNode->begin(), E = DTNode->end();
for (DomTreeDFS::Node::iterator I = DTNode->begin(), E = DTNode->end();
I != E; ++I) {
BasicBlock *Dest = (*I)->getBlock();
DOUT << "Branch thinking about %" << Dest->getName()
<< "(" << PS->Forest->getNodeForBlock(Dest)->getDFSNumIn() << ")\n";
<< "(" << PS->DTDFS->getNodeForBlock(Dest)->getDFSNumIn() << ")\n";
if (Dest == TrueDest) {
DOUT << "(" << DTNode->getBlock()->getName() << ") true set:\n";
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, Dest);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, Dest);
VRP.add(ConstantInt::getTrue(), Condition, ICmpInst::ICMP_EQ);
VRP.solve();
DEBUG(IG.dump());
} else if (Dest == FalseDest) {
DOUT << "(" << DTNode->getBlock()->getName() << ") false set:\n";
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, Dest);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, Dest);
VRP.add(ConstantInt::getFalse(), Condition, ICmpInst::ICMP_EQ);
VRP.solve();
DEBUG(IG.dump());
@ -2209,13 +2379,13 @@ namespace {
// Set the EQProperty in each of the cases BBs, and the NEProperties
// in the default BB.
for (DomTreeNode::iterator I = DTNode->begin(), E = DTNode->end();
for (DomTreeDFS::Node::iterator I = DTNode->begin(), E = DTNode->end();
I != E; ++I) {
BasicBlock *BB = (*I)->getBlock();
DOUT << "Switch thinking about BB %" << BB->getName()
<< "(" << PS->Forest->getNodeForBlock(BB)->getDFSNumIn() << ")\n";
<< "(" << PS->DTDFS->getNodeForBlock(BB)->getDFSNumIn() << ")\n";
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, BB);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, BB);
if (BB == SI.getDefaultDest()) {
for (unsigned i = 1, e = SI.getNumCases(); i < e; ++i)
if (SI.getSuccessor(i) != BB)
@ -2230,7 +2400,7 @@ namespace {
}
void PredicateSimplifier::Forwards::visitAllocaInst(AllocaInst &AI) {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &AI);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &AI);
VRP.add(Constant::getNullValue(AI.getType()), &AI, ICmpInst::ICMP_NE);
VRP.solve();
}
@ -2240,7 +2410,7 @@ namespace {
// avoid "load uint* null" -> null NE null.
if (isa<Constant>(Ptr)) return;
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &LI);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &LI);
VRP.add(Constant::getNullValue(Ptr->getType()), Ptr, ICmpInst::ICMP_NE);
VRP.solve();
}
@ -2249,13 +2419,13 @@ namespace {
Value *Ptr = SI.getPointerOperand();
if (isa<Constant>(Ptr)) return;
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &SI);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &SI);
VRP.add(Constant::getNullValue(Ptr->getType()), Ptr, ICmpInst::ICMP_NE);
VRP.solve();
}
void PredicateSimplifier::Forwards::visitSExtInst(SExtInst &SI) {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &SI);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &SI);
uint32_t SrcBitWidth = cast<IntegerType>(SI.getSrcTy())->getBitWidth();
uint32_t DstBitWidth = cast<IntegerType>(SI.getDestTy())->getBitWidth();
APInt Min(APInt::getHighBitsSet(DstBitWidth, DstBitWidth-SrcBitWidth+1));
@ -2266,7 +2436,7 @@ namespace {
}
void PredicateSimplifier::Forwards::visitZExtInst(ZExtInst &ZI) {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &ZI);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &ZI);
uint32_t SrcBitWidth = cast<IntegerType>(ZI.getSrcTy())->getBitWidth();
uint32_t DstBitWidth = cast<IntegerType>(ZI.getDestTy())->getBitWidth();
APInt Max(APInt::getLowBitsSet(DstBitWidth, SrcBitWidth));
@ -2284,7 +2454,7 @@ namespace {
case Instruction::UDiv:
case Instruction::SDiv: {
Value *Divisor = BO.getOperand(1);
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &BO);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &BO);
VRP.add(Constant::getNullValue(Divisor->getType()), Divisor,
ICmpInst::ICMP_NE);
VRP.solve();
@ -2295,34 +2465,34 @@ namespace {
switch (ops) {
default: break;
case Instruction::Shl: {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &BO);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &BO);
VRP.add(&BO, BO.getOperand(0), ICmpInst::ICMP_UGE);
VRP.solve();
} break;
case Instruction::AShr: {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &BO);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &BO);
VRP.add(&BO, BO.getOperand(0), ICmpInst::ICMP_SLE);
VRP.solve();
} break;
case Instruction::LShr:
case Instruction::UDiv: {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &BO);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &BO);
VRP.add(&BO, BO.getOperand(0), ICmpInst::ICMP_ULE);
VRP.solve();
} break;
case Instruction::URem: {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &BO);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &BO);
VRP.add(&BO, BO.getOperand(1), ICmpInst::ICMP_ULE);
VRP.solve();
} break;
case Instruction::And: {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &BO);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &BO);
VRP.add(&BO, BO.getOperand(0), ICmpInst::ICMP_ULE);
VRP.add(&BO, BO.getOperand(1), ICmpInst::ICMP_ULE);
VRP.solve();
} break;
case Instruction::Or: {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &BO);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &BO);
VRP.add(&BO, BO.getOperand(0), ICmpInst::ICMP_UGE);
VRP.add(&BO, BO.getOperand(1), ICmpInst::ICMP_UGE);
VRP.solve();
@ -2348,7 +2518,7 @@ namespace {
case ICmpInst::ICMP_SGE: Pred = ICmpInst::ICMP_SGT; break;
}
if (Pred != IC.getPredicate()) {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &IC);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &IC);
if (VRP.isRelatedBy(IC.getOperand(1), IC.getOperand(0),
ICmpInst::ICMP_NE)) {
++NumSnuggle;
@ -2376,7 +2546,7 @@ namespace {
}
if (NextVal) {
VRPSolver VRP(IG, UB, VR, PS->Forest, PS->modified, &IC);
VRPSolver VRP(IG, UB, VR, PS->DTDFS, PS->modified, &IC);
if (VRP.isRelatedBy(IC.getOperand(0), NextVal,
ICmpInst::getInversePredicate(Pred))) {
ICmpInst *NewIC = new ICmpInst(ICmpInst::ICMP_EQ, IC.getOperand(0),