[llvm-commits] [llvm] r101117 - in /llvm/trunk: include/llvm/LinkAllPasses.h include/llvm/Transforms/Scalar.h lib/Transforms/Scalar/SCCVN.cpp
Owen Anderson
resistor at mac.com
Mon Apr 12 22:24:08 PDT 2010
Author: resistor
Date: Tue Apr 13 00:24:08 2010
New Revision: 101117
URL: http://llvm.org/viewvc/llvm-project?rev=101117&view=rev
Log:
SCCVN, we hardly knew ye!
Removed:
llvm/trunk/lib/Transforms/Scalar/SCCVN.cpp
Modified:
llvm/trunk/include/llvm/LinkAllPasses.h
llvm/trunk/include/llvm/Transforms/Scalar.h
Modified: llvm/trunk/include/llvm/LinkAllPasses.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/LinkAllPasses.h?rev=101117&r1=101116&r2=101117&view=diff
==============================================================================
--- llvm/trunk/include/llvm/LinkAllPasses.h (original)
+++ llvm/trunk/include/llvm/LinkAllPasses.h Tue Apr 13 00:24:08 2010
@@ -136,7 +136,6 @@
(void) llvm::createSSIPass();
(void) llvm::createSSIEverythingPass();
(void) llvm::createGEPSplitterPass();
- (void) llvm::createSCCVNPass();
(void) llvm::createABCDPass();
(void) llvm::createLintPass();
Modified: llvm/trunk/include/llvm/Transforms/Scalar.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Scalar.h?rev=101117&r1=101116&r2=101117&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Scalar.h (original)
+++ llvm/trunk/include/llvm/Transforms/Scalar.h Tue Apr 13 00:24:08 2010
@@ -326,12 +326,6 @@
//===----------------------------------------------------------------------===//
//
-// SCCVN - Aggressively eliminate redundant scalar values
-//
-FunctionPass *createSCCVNPass();
-
-//===----------------------------------------------------------------------===//
-//
// ABCD - Elimination of Array Bounds Checks on Demand
//
FunctionPass *createABCDPass();
Removed: llvm/trunk/lib/Transforms/Scalar/SCCVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SCCVN.cpp?rev=101116&view=auto
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCVN.cpp (removed)
@@ -1,716 +0,0 @@
-//===- SCCVN.cpp - Eliminate redundant values -----------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass performs global value numbering to eliminate fully redundant
-// instructions. This is based on the paper "SCC-based Value Numbering"
-// by Cooper, et al.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "sccvn"
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/BasicBlock.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/Operator.h"
-#include "llvm/Value.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/PostOrderIterator.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/SparseBitVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/Dominators.h"
-#include "llvm/Support/CFG.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Transforms/Utils/SSAUpdater.h"
-using namespace llvm;
-
-STATISTIC(NumSCCVNInstr, "Number of instructions deleted by SCCVN");
-STATISTIC(NumSCCVNPhi, "Number of phis deleted by SCCVN");
-
-//===----------------------------------------------------------------------===//
-// ValueTable Class
-//===----------------------------------------------------------------------===//
-
-/// This class holds the mapping between values and value numbers. It is used
-/// as an efficient mechanism to determine the expression-wise equivalence of
-/// two values.
-namespace {
- struct Expression {
- enum ExpressionOpcode { ADD, FADD, SUB, FSUB, MUL, FMUL,
- UDIV, SDIV, FDIV, UREM, SREM,
- FREM, SHL, LSHR, ASHR, AND, OR, XOR, ICMPEQ,
- ICMPNE, ICMPUGT, ICMPUGE, ICMPULT, ICMPULE,
- ICMPSGT, ICMPSGE, ICMPSLT, ICMPSLE, FCMPOEQ,
- FCMPOGT, FCMPOGE, FCMPOLT, FCMPOLE, FCMPONE,
- FCMPORD, FCMPUNO, FCMPUEQ, FCMPUGT, FCMPUGE,
- FCMPULT, FCMPULE, FCMPUNE, EXTRACT, INSERT,
- SHUFFLE, SELECT, TRUNC, ZEXT, SEXT, FPTOUI,
- FPTOSI, UITOFP, SITOFP, FPTRUNC, FPEXT,
- PTRTOINT, INTTOPTR, BITCAST, GEP, CALL, CONSTANT,
- INSERTVALUE, EXTRACTVALUE, EMPTY, TOMBSTONE };
-
- ExpressionOpcode opcode;
- const Type* type;
- SmallVector<uint32_t, 4> varargs;
-
- Expression() { }
- Expression(ExpressionOpcode o) : opcode(o) { }
-
- bool operator==(const Expression &other) const {
- if (opcode != other.opcode)
- return false;
- else if (opcode == EMPTY || opcode == TOMBSTONE)
- return true;
- else if (type != other.type)
- return false;
- else {
- if (varargs.size() != other.varargs.size())
- return false;
-
- for (size_t i = 0; i < varargs.size(); ++i)
- if (varargs[i] != other.varargs[i])
- return false;
-
- return true;
- }
- }
-
- bool operator!=(const Expression &other) const {
- return !(*this == other);
- }
- };
-
- class ValueTable {
- private:
- DenseMap<Value*, uint32_t> valueNumbering;
- DenseMap<Expression, uint32_t> expressionNumbering;
- DenseMap<Value*, uint32_t> constantsNumbering;
-
- uint32_t nextValueNumber;
-
- Expression::ExpressionOpcode getOpcode(BinaryOperator* BO);
- Expression::ExpressionOpcode getOpcode(CmpInst* C);
- Expression::ExpressionOpcode getOpcode(CastInst* C);
- Expression create_expression(BinaryOperator* BO);
- Expression create_expression(CmpInst* C);
- Expression create_expression(ShuffleVectorInst* V);
- Expression create_expression(ExtractElementInst* C);
- Expression create_expression(InsertElementInst* V);
- Expression create_expression(SelectInst* V);
- Expression create_expression(CastInst* C);
- Expression create_expression(GetElementPtrInst* G);
- Expression create_expression(CallInst* C);
- Expression create_expression(Constant* C);
- Expression create_expression(ExtractValueInst* C);
- Expression create_expression(InsertValueInst* C);
- public:
- ValueTable() : nextValueNumber(1) { }
- uint32_t computeNumber(Value *V);
- uint32_t lookup(Value *V);
- void add(Value *V, uint32_t num);
- void clear();
- void clearExpressions();
- void erase(Value *v);
- unsigned size();
- void verifyRemoved(const Value *) const;
- };
-}
-
-namespace llvm {
-template <> struct DenseMapInfo<Expression> {
- static inline Expression getEmptyKey() {
- return Expression(Expression::EMPTY);
- }
-
- static inline Expression getTombstoneKey() {
- return Expression(Expression::TOMBSTONE);
- }
-
- static unsigned getHashValue(const Expression e) {
- unsigned hash = e.opcode;
-
- hash = ((unsigned)((uintptr_t)e.type >> 4) ^
- (unsigned)((uintptr_t)e.type >> 9));
-
- for (SmallVector<uint32_t, 4>::const_iterator I = e.varargs.begin(),
- E = e.varargs.end(); I != E; ++I)
- hash = *I + hash * 37;
-
- return hash;
- }
- static bool isEqual(const Expression &LHS, const Expression &RHS) {
- return LHS == RHS;
- }
-};
-template <>
-struct isPodLike<Expression> { static const bool value = true; };
-
-}
-
-//===----------------------------------------------------------------------===//
-// ValueTable Internal Functions
-//===----------------------------------------------------------------------===//
-Expression::ExpressionOpcode ValueTable::getOpcode(BinaryOperator* BO) {
- switch(BO->getOpcode()) {
- default: // THIS SHOULD NEVER HAPPEN
- llvm_unreachable("Binary operator with unknown opcode?");
- case Instruction::Add: return Expression::ADD;
- case Instruction::FAdd: return Expression::FADD;
- case Instruction::Sub: return Expression::SUB;
- case Instruction::FSub: return Expression::FSUB;
- case Instruction::Mul: return Expression::MUL;
- case Instruction::FMul: return Expression::FMUL;
- case Instruction::UDiv: return Expression::UDIV;
- case Instruction::SDiv: return Expression::SDIV;
- case Instruction::FDiv: return Expression::FDIV;
- case Instruction::URem: return Expression::UREM;
- case Instruction::SRem: return Expression::SREM;
- case Instruction::FRem: return Expression::FREM;
- case Instruction::Shl: return Expression::SHL;
- case Instruction::LShr: return Expression::LSHR;
- case Instruction::AShr: return Expression::ASHR;
- case Instruction::And: return Expression::AND;
- case Instruction::Or: return Expression::OR;
- case Instruction::Xor: return Expression::XOR;
- }
-}
-
-Expression::ExpressionOpcode ValueTable::getOpcode(CmpInst* C) {
- if (isa<ICmpInst>(C)) {
- switch (C->getPredicate()) {
- default: // THIS SHOULD NEVER HAPPEN
- llvm_unreachable("Comparison with unknown predicate?");
- case ICmpInst::ICMP_EQ: return Expression::ICMPEQ;
- case ICmpInst::ICMP_NE: return Expression::ICMPNE;
- case ICmpInst::ICMP_UGT: return Expression::ICMPUGT;
- case ICmpInst::ICMP_UGE: return Expression::ICMPUGE;
- case ICmpInst::ICMP_ULT: return Expression::ICMPULT;
- case ICmpInst::ICMP_ULE: return Expression::ICMPULE;
- case ICmpInst::ICMP_SGT: return Expression::ICMPSGT;
- case ICmpInst::ICMP_SGE: return Expression::ICMPSGE;
- case ICmpInst::ICMP_SLT: return Expression::ICMPSLT;
- case ICmpInst::ICMP_SLE: return Expression::ICMPSLE;
- }
- } else {
- switch (C->getPredicate()) {
- default: // THIS SHOULD NEVER HAPPEN
- llvm_unreachable("Comparison with unknown predicate?");
- case FCmpInst::FCMP_OEQ: return Expression::FCMPOEQ;
- case FCmpInst::FCMP_OGT: return Expression::FCMPOGT;
- case FCmpInst::FCMP_OGE: return Expression::FCMPOGE;
- case FCmpInst::FCMP_OLT: return Expression::FCMPOLT;
- case FCmpInst::FCMP_OLE: return Expression::FCMPOLE;
- case FCmpInst::FCMP_ONE: return Expression::FCMPONE;
- case FCmpInst::FCMP_ORD: return Expression::FCMPORD;
- case FCmpInst::FCMP_UNO: return Expression::FCMPUNO;
- case FCmpInst::FCMP_UEQ: return Expression::FCMPUEQ;
- case FCmpInst::FCMP_UGT: return Expression::FCMPUGT;
- case FCmpInst::FCMP_UGE: return Expression::FCMPUGE;
- case FCmpInst::FCMP_ULT: return Expression::FCMPULT;
- case FCmpInst::FCMP_ULE: return Expression::FCMPULE;
- case FCmpInst::FCMP_UNE: return Expression::FCMPUNE;
- }
- }
-}
-
-Expression::ExpressionOpcode ValueTable::getOpcode(CastInst* C) {
- switch(C->getOpcode()) {
- default: // THIS SHOULD NEVER HAPPEN
- llvm_unreachable("Cast operator with unknown opcode?");
- case Instruction::Trunc: return Expression::TRUNC;
- case Instruction::ZExt: return Expression::ZEXT;
- case Instruction::SExt: return Expression::SEXT;
- case Instruction::FPToUI: return Expression::FPTOUI;
- case Instruction::FPToSI: return Expression::FPTOSI;
- case Instruction::UIToFP: return Expression::UITOFP;
- case Instruction::SIToFP: return Expression::SITOFP;
- case Instruction::FPTrunc: return Expression::FPTRUNC;
- case Instruction::FPExt: return Expression::FPEXT;
- case Instruction::PtrToInt: return Expression::PTRTOINT;
- case Instruction::IntToPtr: return Expression::INTTOPTR;
- case Instruction::BitCast: return Expression::BITCAST;
- }
-}
-
-Expression ValueTable::create_expression(CallInst* C) {
- Expression e;
-
- e.type = C->getType();
- e.opcode = Expression::CALL;
-
- e.varargs.push_back(lookup(C->getCalledFunction()));
- for (CallInst::op_iterator I = C->op_begin()+1, E = C->op_end();
- I != E; ++I)
- e.varargs.push_back(lookup(*I));
-
- return e;
-}
-
-Expression ValueTable::create_expression(BinaryOperator* BO) {
- Expression e;
- e.varargs.push_back(lookup(BO->getOperand(0)));
- e.varargs.push_back(lookup(BO->getOperand(1)));
- e.type = BO->getType();
- e.opcode = getOpcode(BO);
-
- return e;
-}
-
-Expression ValueTable::create_expression(CmpInst* C) {
- Expression e;
-
- e.varargs.push_back(lookup(C->getOperand(0)));
- e.varargs.push_back(lookup(C->getOperand(1)));
- e.type = C->getType();
- e.opcode = getOpcode(C);
-
- return e;
-}
-
-Expression ValueTable::create_expression(CastInst* C) {
- Expression e;
-
- e.varargs.push_back(lookup(C->getOperand(0)));
- e.type = C->getType();
- e.opcode = getOpcode(C);
-
- return e;
-}
-
-Expression ValueTable::create_expression(ShuffleVectorInst* S) {
- Expression e;
-
- e.varargs.push_back(lookup(S->getOperand(0)));
- e.varargs.push_back(lookup(S->getOperand(1)));
- e.varargs.push_back(lookup(S->getOperand(2)));
- e.type = S->getType();
- e.opcode = Expression::SHUFFLE;
-
- return e;
-}
-
-Expression ValueTable::create_expression(ExtractElementInst* E) {
- Expression e;
-
- e.varargs.push_back(lookup(E->getOperand(0)));
- e.varargs.push_back(lookup(E->getOperand(1)));
- e.type = E->getType();
- e.opcode = Expression::EXTRACT;
-
- return e;
-}
-
-Expression ValueTable::create_expression(InsertElementInst* I) {
- Expression e;
-
- e.varargs.push_back(lookup(I->getOperand(0)));
- e.varargs.push_back(lookup(I->getOperand(1)));
- e.varargs.push_back(lookup(I->getOperand(2)));
- e.type = I->getType();
- e.opcode = Expression::INSERT;
-
- return e;
-}
-
-Expression ValueTable::create_expression(SelectInst* I) {
- Expression e;
-
- e.varargs.push_back(lookup(I->getCondition()));
- e.varargs.push_back(lookup(I->getTrueValue()));
- e.varargs.push_back(lookup(I->getFalseValue()));
- e.type = I->getType();
- e.opcode = Expression::SELECT;
-
- return e;
-}
-
-Expression ValueTable::create_expression(GetElementPtrInst* G) {
- Expression e;
-
- e.varargs.push_back(lookup(G->getPointerOperand()));
- e.type = G->getType();
- e.opcode = Expression::GEP;
-
- for (GetElementPtrInst::op_iterator I = G->idx_begin(), E = G->idx_end();
- I != E; ++I)
- e.varargs.push_back(lookup(*I));
-
- return e;
-}
-
-Expression ValueTable::create_expression(ExtractValueInst* E) {
- Expression e;
-
- e.varargs.push_back(lookup(E->getAggregateOperand()));
- for (ExtractValueInst::idx_iterator II = E->idx_begin(), IE = E->idx_end();
- II != IE; ++II)
- e.varargs.push_back(*II);
- e.type = E->getType();
- e.opcode = Expression::EXTRACTVALUE;
-
- return e;
-}
-
-Expression ValueTable::create_expression(InsertValueInst* E) {
- Expression e;
-
- e.varargs.push_back(lookup(E->getAggregateOperand()));
- e.varargs.push_back(lookup(E->getInsertedValueOperand()));
- for (InsertValueInst::idx_iterator II = E->idx_begin(), IE = E->idx_end();
- II != IE; ++II)
- e.varargs.push_back(*II);
- e.type = E->getType();
- e.opcode = Expression::INSERTVALUE;
-
- return e;
-}
-
-//===----------------------------------------------------------------------===//
-// ValueTable External Functions
-//===----------------------------------------------------------------------===//
-
-/// add - Insert a value into the table with a specified value number.
-void ValueTable::add(Value *V, uint32_t num) {
- valueNumbering[V] = num;
-}
-
-/// computeNumber - Returns the value number for the specified value, assigning
-/// it a new number if it did not have one before.
-uint32_t ValueTable::computeNumber(Value *V) {
- if (uint32_t v = valueNumbering[V])
- return v;
- else if (uint32_t v= constantsNumbering[V])
- return v;
-
- if (!isa<Instruction>(V)) {
- constantsNumbering[V] = nextValueNumber;
- return nextValueNumber++;
- }
-
- Instruction* I = cast<Instruction>(V);
- Expression exp;
- switch (I->getOpcode()) {
- case Instruction::Add:
- case Instruction::FAdd:
- case Instruction::Sub:
- case Instruction::FSub:
- case Instruction::Mul:
- case Instruction::FMul:
- case Instruction::UDiv:
- case Instruction::SDiv:
- case Instruction::FDiv:
- case Instruction::URem:
- case Instruction::SRem:
- case Instruction::FRem:
- case Instruction::Shl:
- case Instruction::LShr:
- case Instruction::AShr:
- case Instruction::And:
- case Instruction::Or :
- case Instruction::Xor:
- exp = create_expression(cast<BinaryOperator>(I));
- break;
- case Instruction::ICmp:
- case Instruction::FCmp:
- exp = create_expression(cast<CmpInst>(I));
- break;
- case Instruction::Trunc:
- case Instruction::ZExt:
- case Instruction::SExt:
- case Instruction::FPToUI:
- case Instruction::FPToSI:
- case Instruction::UIToFP:
- case Instruction::SIToFP:
- case Instruction::FPTrunc:
- case Instruction::FPExt:
- case Instruction::PtrToInt:
- case Instruction::IntToPtr:
- case Instruction::BitCast:
- exp = create_expression(cast<CastInst>(I));
- break;
- case Instruction::Select:
- exp = create_expression(cast<SelectInst>(I));
- break;
- case Instruction::ExtractElement:
- exp = create_expression(cast<ExtractElementInst>(I));
- break;
- case Instruction::InsertElement:
- exp = create_expression(cast<InsertElementInst>(I));
- break;
- case Instruction::ShuffleVector:
- exp = create_expression(cast<ShuffleVectorInst>(I));
- break;
- case Instruction::ExtractValue:
- exp = create_expression(cast<ExtractValueInst>(I));
- break;
- case Instruction::InsertValue:
- exp = create_expression(cast<InsertValueInst>(I));
- break;
- case Instruction::GetElementPtr:
- exp = create_expression(cast<GetElementPtrInst>(I));
- break;
- default:
- valueNumbering[V] = nextValueNumber;
- return nextValueNumber++;
- }
-
- uint32_t& e = expressionNumbering[exp];
- if (!e) e = nextValueNumber++;
- valueNumbering[V] = e;
-
- return e;
-}
-
-/// lookup - Returns the value number of the specified value. Returns 0 if
-/// the value has not yet been numbered.
-uint32_t ValueTable::lookup(Value *V) {
- if (!isa<Instruction>(V)) {
- if (!constantsNumbering.count(V))
- constantsNumbering[V] = nextValueNumber++;
- return constantsNumbering[V];
- }
-
- return valueNumbering[V];
-}
-
-/// clear - Remove all entries from the ValueTable
-void ValueTable::clear() {
- valueNumbering.clear();
- expressionNumbering.clear();
- constantsNumbering.clear();
- nextValueNumber = 1;
-}
-
-void ValueTable::clearExpressions() {
- expressionNumbering.clear();
- constantsNumbering.clear();
- nextValueNumber = 1;
-}
-
-/// erase - Remove a value from the value numbering
-void ValueTable::erase(Value *V) {
- valueNumbering.erase(V);
-}
-
-/// verifyRemoved - Verify that the value is removed from all internal data
-/// structures.
-void ValueTable::verifyRemoved(const Value *V) const {
- for (DenseMap<Value*, uint32_t>::const_iterator
- I = valueNumbering.begin(), E = valueNumbering.end(); I != E; ++I) {
- assert(I->first != V && "Inst still occurs in value numbering map!");
- }
-}
-
-//===----------------------------------------------------------------------===//
-// SCCVN Pass
-//===----------------------------------------------------------------------===//
-
-namespace {
-
- struct ValueNumberScope {
- ValueNumberScope* parent;
- DenseMap<uint32_t, Value*> table;
- SparseBitVector<128> availIn;
- SparseBitVector<128> availOut;
-
- ValueNumberScope(ValueNumberScope* p) : parent(p) { }
- };
-
- class SCCVN : public FunctionPass {
- bool runOnFunction(Function &F);
- public:
- static char ID; // Pass identification, replacement for typeid
- SCCVN() : FunctionPass(&ID) { }
-
- private:
- ValueTable VT;
- DenseMap<BasicBlock*, ValueNumberScope*> BBMap;
-
- // This transformation requires dominator postdominator info
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<DominatorTree>();
-
- AU.addPreserved<DominatorTree>();
- AU.setPreservesCFG();
- }
- };
-
- char SCCVN::ID = 0;
-}
-
-// createSCCVNPass - The public interface to this file...
-FunctionPass *llvm::createSCCVNPass() { return new SCCVN(); }
-
-static RegisterPass<SCCVN> X("sccvn",
- "SCC Value Numbering");
-
-static Value *lookupNumber(ValueNumberScope *Locals, uint32_t num) {
- while (Locals) {
- DenseMap<uint32_t, Value*>::iterator I = Locals->table.find(num);
- if (I != Locals->table.end())
- return I->second;
- Locals = Locals->parent;
- }
-
- return 0;
-}
-
-bool SCCVN::runOnFunction(Function& F) {
- // Implement the RPO version of the SCCVN algorithm. Conceptually,
- // we optimisitically assume that all instructions with the same opcode have
- // the same VN. Then we deepen our comparison by one level, to all
- // instructions whose operands have the same opcodes get the same VN. We
- // iterate this process until the partitioning stops changing, at which
- // point we have computed a full numbering.
- ReversePostOrderTraversal<Function*> RPOT(&F);
- bool done = false;
- while (!done) {
- done = true;
- VT.clearExpressions();
- for (ReversePostOrderTraversal<Function*>::rpo_iterator I = RPOT.begin(),
- E = RPOT.end(); I != E; ++I) {
- BasicBlock* BB = *I;
- for (BasicBlock::iterator BI = BB->begin(), BE = BB->end();
- BI != BE; ++BI) {
- uint32_t origVN = VT.lookup(BI);
- uint32_t newVN = VT.computeNumber(BI);
- if (origVN != newVN)
- done = false;
- }
- }
- }
-
- // Now, do a dominator walk, eliminating simple, dominated redundancies as we
- // go. Also, build the ValueNumberScope structure that will be used for
- // computing full availability.
- DominatorTree& DT = getAnalysis<DominatorTree>();
- bool changed = false;
- for (df_iterator<DomTreeNode*> DI = df_begin(DT.getRootNode()),
- DE = df_end(DT.getRootNode()); DI != DE; ++DI) {
- BasicBlock* BB = DI->getBlock();
- if (DI->getIDom())
- BBMap[BB] = new ValueNumberScope(BBMap[DI->getIDom()->getBlock()]);
- else
- BBMap[BB] = new ValueNumberScope(0);
-
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
- uint32_t num = VT.lookup(I);
- Value* repl = lookupNumber(BBMap[BB], num);
-
- if (repl) {
- if (isa<PHINode>(I))
- ++NumSCCVNPhi;
- else
- ++NumSCCVNInstr;
- I->replaceAllUsesWith(repl);
- Instruction* OldInst = I;
- ++I;
- BBMap[BB]->table[num] = repl;
- OldInst->eraseFromParent();
- changed = true;
- } else {
- BBMap[BB]->table[num] = I;
- BBMap[BB]->availOut.set(num);
-
- ++I;
- }
- }
- }
-
- // Perform a forward data-flow to compute availability at all points on
- // the CFG.
- do {
- changed = false;
- for (ReversePostOrderTraversal<Function*>::rpo_iterator I = RPOT.begin(),
- E = RPOT.end(); I != E; ++I) {
- BasicBlock* BB = *I;
- ValueNumberScope *VNS = BBMap[BB];
-
- SparseBitVector<128> preds;
- bool first = true;
- for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
- PI != PE; ++PI) {
- if (first) {
- preds = BBMap[*PI]->availOut;
- first = false;
- } else {
- preds &= BBMap[*PI]->availOut;
- }
- }
-
- changed |= (VNS->availIn |= preds);
- changed |= (VNS->availOut |= preds);
- }
- } while (changed);
-
- // Use full availability information to perform non-dominated replacements.
- SSAUpdater SSU;
- for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
- if (!BBMap.count(FI)) continue;
- for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
- BI != BE; ) {
- uint32_t num = VT.lookup(BI);
- if (!BBMap[FI]->availIn.test(num)) {
- ++BI;
- continue;
- }
-
- SSU.Initialize(BI);
-
- SmallPtrSet<BasicBlock*, 8> visited;
- SmallVector<BasicBlock*, 8> stack;
- visited.insert(FI);
- for (pred_iterator PI = pred_begin(FI), PE = pred_end(FI);
- PI != PE; ++PI)
- if (!visited.count(*PI))
- stack.push_back(*PI);
-
- while (!stack.empty()) {
- BasicBlock* CurrBB = stack.pop_back_val();
- visited.insert(CurrBB);
-
- ValueNumberScope* S = BBMap[CurrBB];
- if (S->table.count(num)) {
- SSU.AddAvailableValue(CurrBB, S->table[num]);
- } else {
- for (pred_iterator PI = pred_begin(CurrBB), PE = pred_end(CurrBB);
- PI != PE; ++PI)
- if (!visited.count(*PI))
- stack.push_back(*PI);
- }
- }
-
- Value* repl = SSU.GetValueInMiddleOfBlock(FI);
- BI->replaceAllUsesWith(repl);
- Instruction* CurInst = BI;
- ++BI;
- BBMap[FI]->table[num] = repl;
- if (isa<PHINode>(CurInst))
- ++NumSCCVNPhi;
- else
- ++NumSCCVNInstr;
-
- CurInst->eraseFromParent();
- }
- }
-
- VT.clear();
- for (DenseMap<BasicBlock*, ValueNumberScope*>::iterator
- I = BBMap.begin(), E = BBMap.end(); I != E; ++I)
- delete I->second;
- BBMap.clear();
-
- return changed;
-}
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