//===- ValueNumbering.cpp - Value #'ing Implementation ----------*- C++ -*-===//
//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+//
// This file implements the non-abstract Value Numbering methods as well as a
// default implementation for the analysis group.
//
//===----------------------------------------------------------------------===//
+#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/ValueNumbering.h"
#include "llvm/Support/InstVisitor.h"
#include "llvm/BasicBlock.h"
+#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/Type.h"
-#include "llvm/iMemory.h"
+#include "llvm/Support/Compiler.h"
+using namespace llvm;
+char ValueNumbering::ID = 0;
// Register the ValueNumbering interface, providing a nice name to refer to.
static RegisterAnalysisGroup<ValueNumbering> X("Value Numbering");
// into the tool that uses it. As such, we register and implement the class
// here.
//
+
namespace {
/// BasicVN - This class is the default implementation of the ValueNumbering
/// interface. It walks the SSA def-use chains to trivially identify
/// lexically identical expressions. This does not require any ahead of time
/// analysis, so it is a very fast default implementation.
///
- struct BasicVN : public ImmutablePass, public ValueNumbering {
+ struct VISIBILITY_HIDDEN BasicVN
+ : public ImmutablePass, public ValueNumbering {
+ static char ID; // Class identification, replacement for typeinfo
+ BasicVN() : ImmutablePass((intptr_t)&ID) {}
+
/// getEqualNumberNodes - Return nodes with the same value number as the
/// specified Value. This fills in the argument vector with any equal
/// values.
std::vector<Value*> &RetVals) const;
};
+ char BasicVN::ID = 0;
// Register this pass...
- RegisterOpt<BasicVN>
+ RegisterPass<BasicVN>
X("basicvn", "Basic Value Numbering (default GVN impl)");
// Declare that we implement the ValueNumbering interface
- RegisterAnalysisGroup<ValueNumbering, BasicVN, true> Y;
-} // End of anonymous namespace
+ RegisterAnalysisGroup<ValueNumbering, true> Y(X);
-namespace {
/// BVNImpl - Implement BasicVN in terms of a visitor class that
/// handles the different types of instructions as appropriate.
///
- struct BVNImpl : public InstVisitor<BVNImpl> {
+ struct VISIBILITY_HIDDEN BVNImpl : public InstVisitor<BVNImpl> {
std::vector<Value*> &RetVals;
BVNImpl(std::vector<Value*> &RV) : RetVals(RV) {}
- void handleBinaryInst(Instruction &I);
- void visitBinaryOperator(BinaryOperator &I) {
- handleBinaryInst((Instruction&)I);
- }
- void visitGetElementPtrInst(GetElementPtrInst &I);
void visitCastInst(CastInst &I);
- void visitShiftInst(ShiftInst &I) { handleBinaryInst((Instruction&)I); }
+ void visitGetElementPtrInst(GetElementPtrInst &I);
+ void visitCmpInst(CmpInst &I);
+
+ void handleBinaryInst(Instruction &I);
+ void visitBinaryOperator(Instruction &I) { handleBinaryInst(I); }
+ void visitShiftInst(Instruction &I) { handleBinaryInst(I); }
+ void visitExtractElementInst(Instruction &I) { handleBinaryInst(I); }
+
+ void handleTernaryInst(Instruction &I);
+ void visitSelectInst(Instruction &I) { handleTernaryInst(I); }
+ void visitInsertElementInst(Instruction &I) { handleTernaryInst(I); }
+ void visitShuffleVectorInst(Instruction &I) { handleTernaryInst(I); }
void visitInstruction(Instruction &) {
- // Cannot value number calls or terminator instructions...
+ // Cannot value number calls or terminator instructions.
}
};
}
+ImmutablePass *llvm::createBasicVNPass() { return new BasicVN(); }
+
// getEqualNumberNodes - Return nodes with the same value number as the
// specified Value. This fills in the argument vector with any equal values.
//
Instruction &I = (Instruction&)CI;
Value *Op = I.getOperand(0);
Function *F = I.getParent()->getParent();
-
+
for (Value::use_iterator UI = Op->use_begin(), UE = Op->use_end();
UI != UE; ++UI)
- if (Instruction *Other = dyn_cast<Instruction>(*UI))
- // Check to see if this new cast is not I, but has the same operand...
- if (Other != &I && Other->getOpcode() == I.getOpcode() &&
- Other->getOperand(0) == Op && // Is the operand the same?
- // Is it embeded in the same function? (This could be false if LHS
+ if (CastInst *Other = dyn_cast<CastInst>(*UI))
+ // Check that the opcode is the same
+ if (Other->getOpcode() == Instruction::CastOps(I.getOpcode()) &&
+ // Check that the destination types are the same
+ Other->getType() == I.getType() &&
+ // Is it embedded in the same function? (This could be false if LHS
// is a constant or global!)
Other->getParent()->getParent() == F &&
-
- // Check that the types are the same, since this code handles casts...
- Other->getType() == I.getType()) {
-
+ // Check to see if this new cast is not I.
+ Other != &I) {
// These instructions are identical. Add to list...
RetVals.push_back(Other);
}
}
+void BVNImpl::visitCmpInst(CmpInst &CI1) {
+ Value *LHS = CI1.getOperand(0);
+ for (Value::use_iterator UI = LHS->use_begin(), UE = LHS->use_end();
+ UI != UE; ++UI)
+ if (CmpInst *CI2 = dyn_cast<CmpInst>(*UI))
+ // Check to see if this compare instruction is not CI, but same opcode,
+ // same predicate, and in the same function.
+ if (CI2 != &CI1 && CI2->getOpcode() == CI1.getOpcode() &&
+ CI2->getPredicate() == CI1.getPredicate() &&
+ CI2->getParent()->getParent() == CI1.getParent()->getParent())
+ // If the operands are the same
+ if ((CI2->getOperand(0) == CI1.getOperand(0) &&
+ CI2->getOperand(1) == CI1.getOperand(1)) ||
+ // Or the compare is commutative and the operands are reversed
+ (CI1.isCommutative() &&
+ CI2->getOperand(0) == CI1.getOperand(1) &&
+ CI2->getOperand(1) == CI1.getOperand(0)))
+ // Then the instructiosn are identical, add to list.
+ RetVals.push_back(CI2);
+}
+
+
// isIdenticalBinaryInst - Return true if the two binary instructions are
// identical.
//
static inline bool isIdenticalBinaryInst(const Instruction &I1,
const Instruction *I2) {
- // Is it embeded in the same function? (This could be false if LHS
+ // Is it embedded in the same function? (This could be false if LHS
// is a constant or global!)
if (I1.getOpcode() != I2->getOpcode() ||
I1.getParent()->getParent() != I2->getParent()->getParent())
return false;
-
+
+ // If they are CmpInst instructions, check their predicates
+ if (CmpInst *CI1 = dyn_cast<CmpInst>(&const_cast<Instruction&>(I1)))
+ if (CI1->getPredicate() != cast<CmpInst>(I2)->getPredicate())
+ return false;
+
// They are identical if both operands are the same!
if (I1.getOperand(0) == I2->getOperand(0) &&
I1.getOperand(1) == I2->getOperand(1))
return true;
-
+
// If the instruction is commutative, the instruction can match if the
// operands are swapped!
//
return false;
}
-void BVNImpl::handleBinaryInst(Instruction &I) {
- Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
- Function *F = I.getParent()->getParent();
+// isIdenticalTernaryInst - Return true if the two ternary instructions are
+// identical.
+//
+static inline bool isIdenticalTernaryInst(const Instruction &I1,
+ const Instruction *I2) {
+ // Is it embedded in the same function? (This could be false if LHS
+ // is a constant or global!)
+ if (I1.getParent()->getParent() != I2->getParent()->getParent())
+ return false;
+ // They are identical if all operands are the same!
+ return I1.getOperand(0) == I2->getOperand(0) &&
+ I1.getOperand(1) == I2->getOperand(1) &&
+ I1.getOperand(2) == I2->getOperand(2);
+}
+
+
+
+void BVNImpl::handleBinaryInst(Instruction &I) {
+ Value *LHS = I.getOperand(0);
+
for (Value::use_iterator UI = LHS->use_begin(), UE = LHS->use_end();
UI != UE; ++UI)
if (Instruction *Other = dyn_cast<Instruction>(*UI))
// Check to see if this new binary operator is not I, but same operand...
- if (Other != &I && isIdenticalBinaryInst(I, Other)) {
+ if (Other != &I && isIdenticalBinaryInst(I, Other)) {
// These instructions are identical. Handle the situation.
RetVals.push_back(Other);
}
// using a brute force comparison. This is useful for instructions with an
// arbitrary number of arguments.
//
-static bool IdenticalComplexInst(const Instruction *I1, const Instruction *I2) {
+static inline bool IdenticalComplexInst(const Instruction *I1,
+ const Instruction *I2) {
assert(I1->getOpcode() == I2->getOpcode());
// Equal if they are in the same function...
return I1->getParent()->getParent() == I2->getParent()->getParent() &&
void BVNImpl::visitGetElementPtrInst(GetElementPtrInst &I) {
Value *Op = I.getOperand(0);
- Function *F = I.getParent()->getParent();
-
+
+ // Try to pick a local operand if possible instead of a constant or a global
+ // that might have a lot of uses.
+ for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
+ if (isa<Instruction>(I.getOperand(i)) || isa<Argument>(I.getOperand(i))) {
+ Op = I.getOperand(i);
+ break;
+ }
+
for (Value::use_iterator UI = Op->use_begin(), UE = Op->use_end();
UI != UE; ++UI)
if (GetElementPtrInst *Other = dyn_cast<GetElementPtrInst>(*UI))
RetVals.push_back(Other);
}
}
+
+void BVNImpl::handleTernaryInst(Instruction &I) {
+ Value *Op0 = I.getOperand(0);
+ Instruction *OtherInst;
+
+ for (Value::use_iterator UI = Op0->use_begin(), UE = Op0->use_end();
+ UI != UE; ++UI)
+ if ((OtherInst = dyn_cast<Instruction>(*UI)) &&
+ OtherInst->getOpcode() == I.getOpcode()) {
+ // Check to see if this new select is not I, but has the same operands.
+ if (OtherInst != &I && isIdenticalTernaryInst(I, OtherInst)) {
+ // These instructions are identical. Handle the situation.
+ RetVals.push_back(OtherInst);
+ }
+
+ }
+}
+
+
+// Ensure that users of ValueNumbering.h will link with this file
+DEFINING_FILE_FOR(BasicValueNumbering)
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