//
// 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 is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/Pass.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Support/CFG.h"
+#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/Statistic.h"
STATISTIC(NumFactor , "Number of multiplies factored");
namespace {
- struct ValueEntry {
+ struct VISIBILITY_HIDDEN ValueEntry {
unsigned Rank;
Value *Op;
ValueEntry(unsigned R, Value *O) : Rank(R), Op(O) {}
}
namespace {
- class Reassociate : public FunctionPass {
+ class VISIBILITY_HIDDEN Reassociate : public FunctionPass {
std::map<BasicBlock*, unsigned> RankMap;
std::map<Value*, unsigned> ValueRankMap;
bool MadeChange;
public:
+ static char ID; // Pass identification, replacement for typeid
+ Reassociate() : FunctionPass((intptr_t)&ID) {}
+
bool runOnFunction(Function &F);
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
void RemoveDeadBinaryOp(Value *V);
};
+ char Reassociate::ID = 0;
RegisterPass<Reassociate> X("reassociate", "Reassociate expressions");
}
static Instruction *LowerNegateToMultiply(Instruction *Neg) {
Constant *Cst = ConstantInt::getAllOnesValue(Neg->getType());
- std::string NegName = Neg->getName(); Neg->setName("");
- Instruction *Res = BinaryOperator::createMul(Neg->getOperand(1), Cst, NegName,
- Neg);
+ Instruction *Res = BinaryOperator::createMul(Neg->getOperand(1), Cst, "",Neg);
+ Res->takeName(Neg);
Neg->replaceAllUsesWith(Res);
Neg->eraseFromParent();
return Res;
return BinaryOperator::createNeg(V, V->getName() + ".neg", BI);
}
+/// ShouldBreakUpSubtract - Return true if we should break up this subtract of
+/// X-Y into (X + -Y).
+static bool ShouldBreakUpSubtract(Instruction *Sub) {
+ // If this is a negation, we can't split it up!
+ if (BinaryOperator::isNeg(Sub))
+ return false;
+
+ // Don't bother to break this up unless either the LHS is an associable add or
+ // subtract or if this is only used by one.
+ if (isReassociableOp(Sub->getOperand(0), Instruction::Add) ||
+ isReassociableOp(Sub->getOperand(0), Instruction::Sub))
+ return true;
+ if (isReassociableOp(Sub->getOperand(1), Instruction::Add) ||
+ isReassociableOp(Sub->getOperand(1), Instruction::Sub))
+ return true;
+ if (Sub->hasOneUse() &&
+ (isReassociableOp(Sub->use_back(), Instruction::Add) ||
+ isReassociableOp(Sub->use_back(), Instruction::Sub)))
+ return true;
+
+ return false;
+}
+
/// BreakUpSubtract - If we have (X-Y), and if either X is an add, or if this is
/// only used by an add, transform this into (X+(0-Y)) to promote better
/// reassociation.
static Instruction *BreakUpSubtract(Instruction *Sub) {
- // Don't bother to break this up unless either the LHS is an associable add or
- // if this is only used by one.
- if (!isReassociableOp(Sub->getOperand(0), Instruction::Add) &&
- !isReassociableOp(Sub->getOperand(1), Instruction::Add) &&
- !(Sub->hasOneUse() &&isReassociableOp(Sub->use_back(), Instruction::Add)))
- return 0;
-
// Convert a subtract into an add and a neg instruction... so that sub
// instructions can be commuted with other add instructions...
//
// Calculate the negative value of Operand 1 of the sub instruction...
// and set it as the RHS of the add instruction we just made...
//
- std::string Name = Sub->getName();
- Sub->setName("");
Value *NegVal = NegateValue(Sub->getOperand(1), Sub);
Instruction *New =
- BinaryOperator::createAdd(Sub->getOperand(0), NegVal, Name, Sub);
+ BinaryOperator::createAdd(Sub->getOperand(0), NegVal, "", Sub);
+ New->takeName(Sub);
// Everyone now refers to the add instruction.
Sub->replaceAllUsesWith(New);
Constant *MulCst = ConstantInt::get(Shl->getType(), 1);
MulCst = ConstantExpr::getShl(MulCst, cast<Constant>(Shl->getOperand(1)));
- std::string Name = Shl->getName(); Shl->setName("");
Instruction *Mul = BinaryOperator::createMul(Shl->getOperand(0), MulCst,
- Name, Shl);
+ "", Shl);
+ Mul->takeName(Shl);
Shl->replaceAllUsesWith(Mul);
Shl->eraseFromParent();
return Mul;
switch (Opcode) {
default: break;
case Instruction::And:
- if (CstVal->isNullValue()) { // ... & 0 -> 0
+ if (CstVal->isZero()) { // ... & 0 -> 0
++NumAnnihil;
return CstVal;
} else if (CstVal->isAllOnesValue()) { // ... & -1 -> ...
}
break;
case Instruction::Mul:
- if (CstVal->isNullValue()) { // ... * 0 -> 0
+ if (CstVal->isZero()) { // ... * 0 -> 0
++NumAnnihil;
return CstVal;
- } else if (cast<ConstantInt>(CstVal)->getZExtValue() == 1) {
+ } else if (cast<ConstantInt>(CstVal)->isOne()) {
Ops.pop_back(); // ... * 1 -> ...
}
break;
// FALLTHROUGH!
case Instruction::Add:
case Instruction::Xor:
- if (CstVal->isNullValue()) // ... [|^+] 0 -> ...
+ if (CstVal->isZero()) // ... [|^+] 0 -> ...
Ops.pop_back();
break;
}
++NumFactor;
- if (Ops.size() == 0)
+ if (Ops.empty())
return V2;
// Add the new value to the list of things being added.
// Reject cases where it is pointless to do this.
if (!isa<BinaryOperator>(BI) || BI->getType()->isFloatingPoint() ||
- isa<PackedType>(BI->getType()))
+ isa<VectorType>(BI->getType()))
continue; // Floating point ops are not associative.
// If this is a subtract instruction which is not already in negate form,
// see if we can convert it to X+-Y.
if (BI->getOpcode() == Instruction::Sub) {
- if (!BinaryOperator::isNeg(BI)) {
- if (Instruction *NI = BreakUpSubtract(BI)) {
- MadeChange = true;
- BI = NI;
- }
- } else {
+ if (ShouldBreakUpSubtract(BI)) {
+ BI = BreakUpSubtract(BI);
+ MadeChange = true;
+ } else if (BinaryOperator::isNeg(BI)) {
// Otherwise, this is a negation. See if the operand is a multiply tree
// and if this is not an inner node of a multiply tree.
if (isReassociableOp(BI->getOperand(1), Instruction::Mul) &&
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