//===- 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/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"
+using namespace llvm;
// 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
// Declare that we implement the ValueNumbering interface
RegisterAnalysisGroup<ValueNumbering, BasicVN, true> Y;
-} // End of anonymous namespace
-namespace {
/// BVNImpl - Implement BasicVN in terms of a visitor class that
/// handles the different types of instructions as appropriate.
///
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?
+ if (CastInst *Other = dyn_cast<CastInst>(*UI))
+ // Check that the types are the same, since this code handles casts...
+ if (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::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)
RetVals.push_back(Other);
}
}
+
+void llvm::BasicValueNumberingStub() { }