//===- InstructionCombining.cpp - Combine multiple instructions -----------===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
//
// InstructionCombining - Combine instructions to form fewer, simple
// instructions. This pass does not modify the CFG This pass is where algebraic
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/Constants.h"
-#include "llvm/ConstantHandling.h"
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalVariable.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Support/InstIterator.h"
#include "llvm/Support/InstVisitor.h"
#include "llvm/Support/CallSite.h"
#include "Support/Statistic.h"
#include <algorithm>
+using namespace llvm;
namespace {
Statistic<> NumCombined ("instcombine", "Number of insts combined");
public InstVisitor<InstCombiner, Instruction*> {
// Worklist of all of the instructions that need to be simplified.
std::vector<Instruction*> WorkList;
+ TargetData *TD;
void AddUsesToWorkList(Instruction &I) {
// The instruction was simplified, add all users of the instruction to
virtual bool runOnFunction(Function &F);
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<TargetData>();
AU.setPreservesCFG();
}
Instruction *visitPHINode(PHINode &PN);
Instruction *visitGetElementPtrInst(GetElementPtrInst &GEP);
Instruction *visitAllocationInst(AllocationInst &AI);
+ Instruction *visitFreeInst(FreeInst &FI);
Instruction *visitLoadInst(LoadInst &LI);
Instruction *visitBranchInst(BranchInst &BI);
// InsertNewInstBefore - insert an instruction New before instruction Old
// in the program. Add the new instruction to the worklist.
//
- void InsertNewInstBefore(Instruction *New, Instruction &Old) {
+ Value *InsertNewInstBefore(Instruction *New, Instruction &Old) {
assert(New && New->getParent() == 0 &&
"New instruction already inserted into a basic block!");
BasicBlock *BB = Old.getParent();
BB->getInstList().insert(&Old, New); // Insert inst
WorkList.push_back(New); // Add to worklist
+ return New;
}
public:
// isOnlyUse - Return true if this instruction will be deleted if we stop using
// it.
static bool isOnlyUse(Value *V) {
- return V->use_size() == 1 || isa<Constant>(V);
+ return V->hasOneUse() || isa<Constant>(V);
+}
+
+// getSignedIntegralType - Given an unsigned integral type, return the signed
+// version of it that has the same size.
+static const Type *getSignedIntegralType(const Type *Ty) {
+ switch (Ty->getPrimitiveID()) {
+ default: assert(0 && "Invalid unsigned integer type!"); abort();
+ case Type::UByteTyID: return Type::SByteTy;
+ case Type::UShortTyID: return Type::ShortTy;
+ case Type::UIntTyID: return Type::IntTy;
+ case Type::ULongTyID: return Type::LongTy;
+ }
+}
+
+// getPromotedType - Return the specified type promoted as it would be to pass
+// though a va_arg area...
+static const Type *getPromotedType(const Type *Ty) {
+ switch (Ty->getPrimitiveID()) {
+ case Type::SByteTyID:
+ case Type::ShortTyID: return Type::IntTy;
+ case Type::UByteTyID:
+ case Type::UShortTyID: return Type::UIntTy;
+ case Type::FloatTyID: return Type::DoubleTy;
+ default: return Ty;
+ }
}
// SimplifyCommutative - This performs a few simplifications for commutative
return 0;
}
+static Constant *NotConstant(Constant *C) {
+ return ConstantExpr::get(Instruction::Xor, C,
+ ConstantIntegral::getAllOnesValue(C->getType()));
+}
+
static inline Value *dyn_castNotVal(Value *V) {
if (BinaryOperator::isNot(V))
return BinaryOperator::getNotArgument(cast<BinaryOperator>(V));
// Constants can be considered to be not'ed values...
if (ConstantIntegral *C = dyn_cast<ConstantIntegral>(V))
- return ConstantExpr::get(Instruction::Xor,
- ConstantIntegral::getAllOnesValue(C->getType()),C);
+ return NotConstant(C);
return 0;
}
// non-constant operand of the multiply.
//
static inline Value *dyn_castFoldableMul(Value *V) {
- if (V->use_size() == 1 && V->getType()->isInteger())
+ if (V->hasOneUse() && V->getType()->isInteger())
if (Instruction *I = dyn_cast<Instruction>(V))
if (I->getOpcode() == Instruction::Mul)
if (isa<Constant>(I->getOperand(1)))
// Otherwise, if the LHS is not of the same opcode as the root, return.
Instruction *LHSI = dyn_cast<Instruction>(LHS);
- while (LHSI && LHSI->getOpcode() == Opcode && LHSI->use_size() == 1) {
+ while (LHSI && LHSI->getOpcode() == Opcode && LHSI->hasOneUse()) {
// Should we apply this transform to the RHS?
bool ShouldApply = F.shouldApply(LHSI->getOperand(1));
if (ConstantInt *XorRHS = dyn_cast<ConstantInt>(ILHS->getOperand(1)))
if (XorRHS->isAllOnesValue())
return BinaryOperator::create(Instruction::Sub,
- *CRHS - *ConstantInt::get(I.getType(), 1),
+ ConstantExpr::get(Instruction::Sub,
+ CRHS, ConstantInt::get(I.getType(), 1)),
ILHS->getOperand(0));
break;
default: break;
if (Value *V = dyn_castNegVal(Op1))
return BinaryOperator::create(Instruction::Add, Op0, V);
- // Replace (-1 - A) with (~A)...
- if (ConstantInt *C = dyn_cast<ConstantInt>(Op0))
+ if (ConstantInt *C = dyn_cast<ConstantInt>(Op0)) {
+ // Replace (-1 - A) with (~A)...
if (C->isAllOnesValue())
return BinaryOperator::createNot(Op1);
+ // C - ~X == X + (1+C)
+ if (BinaryOperator::isNot(Op1))
+ return BinaryOperator::create(Instruction::Add,
+ BinaryOperator::getNotArgument(cast<BinaryOperator>(Op1)),
+ ConstantExpr::get(Instruction::Add, C,
+ ConstantInt::get(I.getType(), 1)));
+ }
+
if (BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1))
- if (Op1I->use_size() == 1) {
+ if (Op1I->hasOneUse()) {
// Replace (x - (y - z)) with (x + (z - y)) if the (y - z) subexpression
// is not used by anyone else...
//
- if (Op1I->getOpcode() == Instruction::Sub) {
+ if (Op1I->getOpcode() == Instruction::Sub &&
+ !Op1I->getType()->isFloatingPoint()) {
// Swap the two operands of the subexpr...
Value *IIOp0 = Op1I->getOperand(0), *IIOp1 = Op1I->getOperand(1);
Op1I->setOperand(0, IIOp1);
return 0;
}
+/// isSignBitCheck - Given an exploded setcc instruction, return true if it is
+/// really just returns true if the most significant (sign) bit is set.
+static bool isSignBitCheck(unsigned Opcode, Value *LHS, ConstantInt *RHS) {
+ if (RHS->getType()->isSigned()) {
+ // True if source is LHS < 0 or LHS <= -1
+ return Opcode == Instruction::SetLT && RHS->isNullValue() ||
+ Opcode == Instruction::SetLE && RHS->isAllOnesValue();
+ } else {
+ ConstantUInt *RHSC = cast<ConstantUInt>(RHS);
+ // True if source is LHS > 127 or LHS >= 128, where the constants depend on
+ // the size of the integer type.
+ if (Opcode == Instruction::SetGE)
+ return RHSC->getValue() == 1ULL<<(RHS->getType()->getPrimitiveSize()*8-1);
+ if (Opcode == Instruction::SetGT)
+ return RHSC->getValue() ==
+ (1ULL << (RHS->getType()->getPrimitiveSize()*8-1))-1;
+ }
+ return false;
+}
+
Instruction *InstCombiner::visitMul(BinaryOperator &I) {
bool Changed = SimplifyCommutative(I);
Value *Op0 = I.getOperand(0);
if (SI->getOpcode() == Instruction::Shl)
if (Constant *ShOp = dyn_cast<Constant>(SI->getOperand(1)))
return BinaryOperator::create(Instruction::Mul, SI->getOperand(0),
- *CI << *ShOp);
-
+ ConstantExpr::get(Instruction::Shl, CI, ShOp));
+
if (CI->isNullValue())
return ReplaceInstUsesWith(I, Op1); // X * 0 == 0
if (CI->equalsInt(1)) // X * 1 == X
if (Value *Op1v = dyn_castNegVal(I.getOperand(1)))
return BinaryOperator::create(Instruction::Mul, Op0v, Op1v);
+ // If one of the operands of the multiply is a cast from a boolean value, then
+ // we know the bool is either zero or one, so this is a 'masking' multiply.
+ // See if we can simplify things based on how the boolean was originally
+ // formed.
+ CastInst *BoolCast = 0;
+ if (CastInst *CI = dyn_cast<CastInst>(I.getOperand(0)))
+ if (CI->getOperand(0)->getType() == Type::BoolTy)
+ BoolCast = CI;
+ if (!BoolCast)
+ if (CastInst *CI = dyn_cast<CastInst>(I.getOperand(1)))
+ if (CI->getOperand(0)->getType() == Type::BoolTy)
+ BoolCast = CI;
+ if (BoolCast) {
+ if (SetCondInst *SCI = dyn_cast<SetCondInst>(BoolCast->getOperand(0))) {
+ Value *SCIOp0 = SCI->getOperand(0), *SCIOp1 = SCI->getOperand(1);
+ const Type *SCOpTy = SCIOp0->getType();
+
+ // If the setcc is true iff the sign bit of X is set, then convert this
+ // multiply into a shift/and combination.
+ if (isa<ConstantInt>(SCIOp1) &&
+ isSignBitCheck(SCI->getOpcode(), SCIOp0, cast<ConstantInt>(SCIOp1))) {
+ // Shift the X value right to turn it into "all signbits".
+ Constant *Amt = ConstantUInt::get(Type::UByteTy,
+ SCOpTy->getPrimitiveSize()*8-1);
+ if (SCIOp0->getType()->isUnsigned()) {
+ const Type *NewTy = getSignedIntegralType(SCIOp0->getType());
+ SCIOp0 = InsertNewInstBefore(new CastInst(SCIOp0, NewTy,
+ SCIOp0->getName()), I);
+ }
+
+ Value *V =
+ InsertNewInstBefore(new ShiftInst(Instruction::Shr, SCIOp0, Amt,
+ BoolCast->getOperand(0)->getName()+
+ ".mask"), I);
+
+ // If the multiply type is not the same as the source type, sign extend
+ // or truncate to the multiply type.
+ if (I.getType() != V->getType())
+ V = InsertNewInstBefore(new CastInst(V, I.getType(), V->getName()),I);
+
+ Value *OtherOp = Op0 == BoolCast ? I.getOperand(1) : Op0;
+ return BinaryOperator::create(Instruction::And, V, OtherOp);
+ }
+ }
+ }
+
return Changed ? &I : 0;
}
ConstantIntegral *AndRHS,
BinaryOperator &TheAnd) {
Value *X = Op->getOperand(0);
+ Constant *Together = 0;
+ if (!isa<ShiftInst>(Op))
+ Together = ConstantExpr::get(Instruction::And, AndRHS, OpRHS);
+
switch (Op->getOpcode()) {
case Instruction::Xor:
- if ((*AndRHS & *OpRHS)->isNullValue()) {
+ if (Together->isNullValue()) {
// (X ^ C1) & C2 --> (X & C2) iff (C1&C2) == 0
return BinaryOperator::create(Instruction::And, X, AndRHS);
- } else if (Op->use_size() == 1) {
+ } else if (Op->hasOneUse()) {
// (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
std::string OpName = Op->getName(); Op->setName("");
Instruction *And = BinaryOperator::create(Instruction::And,
X, AndRHS, OpName);
InsertNewInstBefore(And, TheAnd);
- return BinaryOperator::create(Instruction::Xor, And, *AndRHS & *OpRHS);
+ return BinaryOperator::create(Instruction::Xor, And, Together);
}
break;
case Instruction::Or:
// (X | C1) & C2 --> X & C2 iff C1 & C1 == 0
- if ((*AndRHS & *OpRHS)->isNullValue())
+ if (Together->isNullValue())
return BinaryOperator::create(Instruction::And, X, AndRHS);
else {
- Constant *Together = *AndRHS & *OpRHS;
if (Together == AndRHS) // (X | C) & C --> C
return ReplaceInstUsesWith(TheAnd, AndRHS);
- if (Op->use_size() == 1 && Together != OpRHS) {
+ if (Op->hasOneUse() && Together != OpRHS) {
// (X | C1) & C2 --> (X | (C1&C2)) & C2
std::string Op0Name = Op->getName(); Op->setName("");
Instruction *Or = BinaryOperator::create(Instruction::Or, X,
}
break;
case Instruction::Add:
- if (Op->use_size() == 1) {
+ if (Op->hasOneUse()) {
// Adding a one to a single bit bit-field should be turned into an XOR
// of the bit. First thing to check is to see if this AND is with a
// single bit constant.
// the anded constant includes them, clear them now!
//
Constant *AllOne = ConstantIntegral::getAllOnesValue(AndRHS->getType());
- Constant *CI = *AndRHS & *(*AllOne << *OpRHS);
+ Constant *CI = ConstantExpr::get(Instruction::And, AndRHS,
+ ConstantExpr::get(Instruction::Shl, AllOne, OpRHS));
if (CI != AndRHS) {
TheAnd.setOperand(1, CI);
return &TheAnd;
//
if (AndRHS->getType()->isUnsigned()) {
Constant *AllOne = ConstantIntegral::getAllOnesValue(AndRHS->getType());
- Constant *CI = *AndRHS & *(*AllOne >> *OpRHS);
+ Constant *CI = ConstantExpr::get(Instruction::And, AndRHS,
+ ConstantExpr::get(Instruction::Shr, AllOne, OpRHS));
if (CI != AndRHS) {
TheAnd.setOperand(1, CI);
return &TheAnd;
Op0I->getOperand(0), RHS,
Op0Name);
InsertNewInstBefore(Or, I);
- return BinaryOperator::create(Instruction::And, Or, *RHS | *Op0CI);
+ return BinaryOperator::create(Instruction::And, Or,
+ ConstantExpr::get(Instruction::Or, RHS, Op0CI));
}
// (X ^ C1) | C2 --> (X | C2) ^ (C1&~C2)
Op0I->getOperand(0), RHS,
Op0Name);
InsertNewInstBefore(Or, I);
- return BinaryOperator::create(Instruction::Xor, Or, *Op0CI & *~*RHS);
+ return BinaryOperator::create(Instruction::Xor, Or,
+ ConstantExpr::get(Instruction::And, Op0CI,
+ NotConstant(RHS)));
}
}
}
if (Constant *C0 = dyn_castMaskingAnd(LHS))
if (Constant *C1 = dyn_castMaskingAnd(RHS))
return BinaryOperator::create(Instruction::And, LHS->getOperand(0),
- *C0 | *C1);
+ ConstantExpr::get(Instruction::Or, C0, C1));
Value *Op0NotVal = dyn_castNotVal(Op0);
Value *Op1NotVal = dyn_castNotVal(Op1);
return Changed ? &I : 0;
}
+// XorSelf - Implements: X ^ X --> 0
+struct XorSelf {
+ Value *RHS;
+ XorSelf(Value *rhs) : RHS(rhs) {}
+ bool shouldApply(Value *LHS) const { return LHS == RHS; }
+ Instruction *apply(BinaryOperator &Xor) const {
+ return &Xor;
+ }
+};
Instruction *InstCombiner::visitXor(BinaryOperator &I) {
bool Changed = SimplifyCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
- // xor X, X = 0
- if (Op0 == Op1)
+ // xor X, X = 0, even if X is nested in a sequence of Xor's.
+ if (Instruction *Result = AssociativeOpt(I, XorSelf(Op1))) {
+ assert(Result == &I && "AssociativeOpt didn't work?");
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
+ }
if (ConstantIntegral *RHS = dyn_cast<ConstantIntegral>(Op1)) {
// xor X, 0 == X
if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
// xor (setcc A, B), true = not (setcc A, B) = setncc A, B
if (SetCondInst *SCI = dyn_cast<SetCondInst>(Op0I))
- if (RHS == ConstantBool::True && SCI->use_size() == 1)
+ if (RHS == ConstantBool::True && SCI->hasOneUse())
return new SetCondInst(SCI->getInverseCondition(),
SCI->getOperand(0), SCI->getOperand(1));
+
+ // ~(c-X) == X-c-1 == X+(-c-1)
+ if (Op0I->getOpcode() == Instruction::Sub && RHS->isAllOnesValue())
+ if (Constant *Op0I0C = dyn_cast<Constant>(Op0I->getOperand(0))) {
+ Constant *NegOp0I0C = ConstantExpr::get(Instruction::Sub,
+ Constant::getNullValue(Op0I0C->getType()), Op0I0C);
+ Constant *ConstantRHS = ConstantExpr::get(Instruction::Sub, NegOp0I0C,
+ ConstantInt::get(I.getType(), 1));
+ return BinaryOperator::create(Instruction::Add, Op0I->getOperand(1),
+ ConstantRHS);
+ }
if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
- if (Op0I->getOpcode() == Instruction::And) {
+ switch (Op0I->getOpcode()) {
+ case Instruction::Add:
+ // ~(X-c) --> (-c-1)-X
+ if (RHS->isAllOnesValue()) {
+ Constant *NegOp0CI = ConstantExpr::get(Instruction::Sub,
+ Constant::getNullValue(Op0CI->getType()), Op0CI);
+ return BinaryOperator::create(Instruction::Sub,
+ ConstantExpr::get(Instruction::Sub, NegOp0CI,
+ ConstantInt::get(I.getType(), 1)),
+ Op0I->getOperand(0));
+ }
+ break;
+ case Instruction::And:
// (X & C1) ^ C2 --> (X & C1) | C2 iff (C1&C2) == 0
- if ((*RHS & *Op0CI)->isNullValue())
+ if (ConstantExpr::get(Instruction::And, RHS, Op0CI)->isNullValue())
return BinaryOperator::create(Instruction::Or, Op0, RHS);
- } else if (Op0I->getOpcode() == Instruction::Or) {
+ break;
+ case Instruction::Or:
// (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
- if ((*RHS & *Op0CI) == RHS)
- return BinaryOperator::create(Instruction::And, Op0, ~*RHS);
+ if (ConstantExpr::get(Instruction::And, RHS, Op0CI) == RHS)
+ return BinaryOperator::create(Instruction::And, Op0,
+ NotConstant(RHS));
+ break;
+ default: break;
}
}
}
ConstantIntegral::getAllOnesValue(I.getType()));
if (Instruction *Op1I = dyn_cast<Instruction>(Op1))
- if (Op1I->getOpcode() == Instruction::Or)
+ if (Op1I->getOpcode() == Instruction::Or) {
if (Op1I->getOperand(0) == Op0) { // B^(B|A) == (A|B)^B
cast<BinaryOperator>(Op1I)->swapOperands();
I.swapOperands();
} else if (Op1I->getOperand(1) == Op0) { // B^(A|B) == (A|B)^B
I.swapOperands();
std::swap(Op0, Op1);
- }
+ }
+ } else if (Op1I->getOpcode() == Instruction::Xor) {
+ if (Op0 == Op1I->getOperand(0)) // A^(A^B) == B
+ return ReplaceInstUsesWith(I, Op1I->getOperand(1));
+ else if (Op0 == Op1I->getOperand(1)) // A^(B^A) == B
+ return ReplaceInstUsesWith(I, Op1I->getOperand(0));
+ }
if (Instruction *Op0I = dyn_cast<Instruction>(Op0))
- if (Op0I->getOpcode() == Instruction::Or && Op0I->use_size() == 1) {
+ if (Op0I->getOpcode() == Instruction::Or && Op0I->hasOneUse()) {
if (Op0I->getOperand(0) == Op1) // (B|A)^B == (A|B)^B
cast<BinaryOperator>(Op0I)->swapOperands();
if (Op0I->getOperand(1) == Op1) { // (A|B)^B == A & ~B
return BinaryOperator::create(Instruction::And, Op0I->getOperand(0),
NotB);
}
+ } else if (Op0I->getOpcode() == Instruction::Xor) {
+ if (Op1 == Op0I->getOperand(0)) // (A^B)^A == B
+ return ReplaceInstUsesWith(I, Op0I->getOperand(1));
+ else if (Op1 == Op0I->getOperand(1)) // (B^A)^A == B
+ return ReplaceInstUsesWith(I, Op0I->getOperand(0));
}
// (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1^C2 == 0
if (Ty == Type::BoolTy) {
// If this is <, >, or !=, we can change this into a simple xor instruction
if (!isTrueWhenEqual(I))
- return BinaryOperator::create(Instruction::Xor, Op0, Op1, I.getName());
+ return BinaryOperator::create(Instruction::Xor, Op0, Op1);
// Otherwise we need to make a temporary intermediate instruction and insert
// it into the instruction stream. This is what we are after:
Instruction *Xor = BinaryOperator::create(Instruction::Xor, Op0, Op1,
I.getName()+"tmp");
InsertNewInstBefore(Xor, I);
- return BinaryOperator::createNot(Xor, I.getName());
+ return BinaryOperator::createNot(Xor);
}
// Handle the setXe cases...
// Now we just have the SetLE case.
Instruction *Not = BinaryOperator::createNot(Op0, I.getName()+"tmp");
InsertNewInstBefore(Not, I);
- return BinaryOperator::create(Instruction::Or, Not, Op1, I.getName());
+ return BinaryOperator::create(Instruction::Or, Not, Op1);
}
// Check to see if we are doing one of many comparisons against constant
return new SetCondInst(I.getOpcode(), BOp0, NegVal);
else if (Value *NegVal = dyn_castNegVal(BOp0))
return new SetCondInst(I.getOpcode(), NegVal, BOp1);
- else if (BO->use_size() == 1) {
+ else if (BO->hasOneUse()) {
Instruction *Neg = BinaryOperator::createNeg(BOp1, BO->getName());
BO->setName("");
InsertNewInstBefore(Neg, I);
// the explicit xor.
if (Constant *BOC = dyn_cast<Constant>(BO->getOperand(1)))
return BinaryOperator::create(I.getOpcode(), BO->getOperand(0),
- *CI ^ *BOC);
+ ConstantExpr::get(Instruction::Xor, CI, BOC));
// FALLTHROUGH
case Instruction::Sub:
case Instruction::Or:
// If bits are being or'd in that are not present in the constant we
// are comparing against, then the comparison could never succeed!
- if (Constant *BOC = dyn_cast<Constant>(BO->getOperand(1)))
- if (!(*BOC & *~*CI)->isNullValue())
+ if (Constant *BOC = dyn_cast<Constant>(BO->getOperand(1))) {
+ Constant *NotCI = NotConstant(CI);
+ if (!ConstantExpr::get(Instruction::And, BOC, NotCI)->isNullValue())
return ReplaceInstUsesWith(I, ConstantBool::get(isSetNE));
+ }
break;
case Instruction::And:
if (ConstantInt *BOC = dyn_cast<ConstantInt>(BO->getOperand(1))) {
// If bits are being compared against that are and'd out, then the
// comparison can never succeed!
- if (!(*CI & *~*BOC)->isNullValue())
+ if (!ConstantExpr::get(Instruction::And, CI,
+ NotConstant(BOC))->isNullValue())
return ReplaceInstUsesWith(I, ConstantBool::get(isSetNE));
// Replace (and X, (1 << size(X)-1) != 0) with x < 0, converting X
Value *X = BO->getOperand(0);
// If 'X' is not signed, insert a cast now...
if (!BOC->getType()->isSigned()) {
- const Type *DestTy;
- switch (BOC->getType()->getPrimitiveID()) {
- case Type::UByteTyID: DestTy = Type::SByteTy; break;
- case Type::UShortTyID: DestTy = Type::ShortTy; break;
- case Type::UIntTyID: DestTy = Type::IntTy; break;
- case Type::ULongTyID: DestTy = Type::LongTy; break;
- default: assert(0 && "Invalid unsigned integer type!"); abort();
- }
+ const Type *DestTy = getSignedIntegralType(BOC->getType());
CastInst *NewCI = new CastInst(X,DestTy,X->getName()+".signed");
InsertNewInstBefore(NewCI, I);
X = NewCI;
default: break;
}
}
+ } else { // Not a SetEQ/SetNE
+ // If the LHS is a cast from an integral value of the same size,
+ if (CastInst *Cast = dyn_cast<CastInst>(Op0)) {
+ Value *CastOp = Cast->getOperand(0);
+ const Type *SrcTy = CastOp->getType();
+ unsigned SrcTySize = SrcTy->getPrimitiveSize();
+ if (SrcTy != Cast->getType() && SrcTy->isInteger() &&
+ SrcTySize == Cast->getType()->getPrimitiveSize()) {
+ assert((SrcTy->isSigned() ^ Cast->getType()->isSigned()) &&
+ "Source and destination signednesses should differ!");
+ if (Cast->getType()->isSigned()) {
+ // If this is a signed comparison, check for comparisons in the
+ // vicinity of zero.
+ if (I.getOpcode() == Instruction::SetLT && CI->isNullValue())
+ // X < 0 => x > 127
+ return BinaryOperator::create(Instruction::SetGT, CastOp,
+ ConstantUInt::get(SrcTy, (1ULL << (SrcTySize*8-1))-1));
+ else if (I.getOpcode() == Instruction::SetGT &&
+ cast<ConstantSInt>(CI)->getValue() == -1)
+ // X > -1 => x < 128
+ return BinaryOperator::create(Instruction::SetGT, CastOp,
+ ConstantUInt::get(SrcTy, 1ULL << (SrcTySize*8-1)));
+ } else {
+ ConstantUInt *CUI = cast<ConstantUInt>(CI);
+ if (I.getOpcode() == Instruction::SetLT &&
+ CUI->getValue() == 1ULL << (SrcTySize*8-1))
+ // X < 128 => X > -1
+ return BinaryOperator::create(Instruction::SetGT, CastOp,
+ ConstantSInt::get(SrcTy, -1));
+ else if (I.getOpcode() == Instruction::SetGT &&
+ CUI->getValue() == (1ULL << (SrcTySize*8-1))-1)
+ // X > 127 => X < 0
+ return BinaryOperator::create(Instruction::SetLT, CastOp,
+ Constant::getNullValue(SrcTy));
+ }
+ }
+ }
}
// Check to see if we are comparing against the minimum or maximum value...
if (I.getOpcode() == Instruction::SetGE) // A >= MIN -> TRUE
return ReplaceInstUsesWith(I, ConstantBool::True);
if (I.getOpcode() == Instruction::SetLE) // A <= MIN -> A == MIN
- return BinaryOperator::create(Instruction::SetEQ, Op0,Op1, I.getName());
+ return BinaryOperator::create(Instruction::SetEQ, Op0, Op1);
if (I.getOpcode() == Instruction::SetGT) // A > MIN -> A != MIN
- return BinaryOperator::create(Instruction::SetNE, Op0,Op1, I.getName());
+ return BinaryOperator::create(Instruction::SetNE, Op0, Op1);
} else if (CI->isMaxValue()) {
if (I.getOpcode() == Instruction::SetGT) // A > MAX -> FALSE
if (I.getOpcode() == Instruction::SetLE) // A <= MAX -> TRUE
return ReplaceInstUsesWith(I, ConstantBool::True);
if (I.getOpcode() == Instruction::SetGE) // A >= MAX -> A == MAX
- return BinaryOperator::create(Instruction::SetEQ, Op0,Op1, I.getName());
+ return BinaryOperator::create(Instruction::SetEQ, Op0, Op1);
if (I.getOpcode() == Instruction::SetLT) // A < MAX -> A != MAX
- return BinaryOperator::create(Instruction::SetNE, Op0,Op1, I.getName());
+ return BinaryOperator::create(Instruction::SetNE, Op0, Op1);
// Comparing against a value really close to min or max?
} else if (isMinValuePlusOne(CI)) {
if (I.getOpcode() == Instruction::SetLT) // A < MIN+1 -> A == MIN
- return BinaryOperator::create(Instruction::SetEQ, Op0,
- SubOne(CI), I.getName());
+ return BinaryOperator::create(Instruction::SetEQ, Op0, SubOne(CI));
if (I.getOpcode() == Instruction::SetGE) // A >= MIN-1 -> A != MIN
- return BinaryOperator::create(Instruction::SetNE, Op0,
- SubOne(CI), I.getName());
+ return BinaryOperator::create(Instruction::SetNE, Op0, SubOne(CI));
} else if (isMaxValueMinusOne(CI)) {
if (I.getOpcode() == Instruction::SetGT) // A > MAX-1 -> A == MAX
- return BinaryOperator::create(Instruction::SetEQ, Op0,
- AddOne(CI), I.getName());
+ return BinaryOperator::create(Instruction::SetEQ, Op0, AddOne(CI));
if (I.getOpcode() == Instruction::SetLE) // A <= MAX-1 -> A != MAX
- return BinaryOperator::create(Instruction::SetNE, Op0,
- AddOne(CI), I.getName());
+ return BinaryOperator::create(Instruction::SetNE, Op0, AddOne(CI));
}
+
+ // If we still have a setle or setge instruction, turn it into the
+ // appropriate setlt or setgt instruction. Since the border cases have
+ // already been handled above, this requires little checking.
+ //
+ if (I.getOpcode() == Instruction::SetLE)
+ return BinaryOperator::create(Instruction::SetLT, Op0, AddOne(CI));
+ if (I.getOpcode() == Instruction::SetGE)
+ return BinaryOperator::create(Instruction::SetGT, Op0, SubOne(CI));
}
+ // Test to see if the operands of the setcc are casted versions of other
+ // values. If the cast can be stripped off both arguments, we do so now.
+ if (CastInst *CI = dyn_cast<CastInst>(Op0)) {
+ Value *CastOp0 = CI->getOperand(0);
+ if (CastOp0->getType()->isLosslesslyConvertibleTo(CI->getType()) &&
+ !isa<Argument>(Op1) &&
+ (I.getOpcode() == Instruction::SetEQ ||
+ I.getOpcode() == Instruction::SetNE)) {
+ // We keep moving the cast from the left operand over to the right
+ // operand, where it can often be eliminated completely.
+ Op0 = CastOp0;
+
+ // If operand #1 is a cast instruction, see if we can eliminate it as
+ // well.
+ if (CastInst *CI2 = dyn_cast<CastInst>(Op1))
+ if (CI2->getOperand(0)->getType()->isLosslesslyConvertibleTo(
+ Op0->getType()))
+ Op1 = CI2->getOperand(0);
+
+ // If Op1 is a constant, we can fold the cast into the constant.
+ if (Op1->getType() != Op0->getType())
+ if (Constant *Op1C = dyn_cast<Constant>(Op1)) {
+ Op1 = ConstantExpr::getCast(Op1C, Op0->getType());
+ } else {
+ // Otherwise, cast the RHS right before the setcc
+ Op1 = new CastInst(Op1, Op0->getType(), Op1->getName());
+ InsertNewInstBefore(cast<Instruction>(Op1), I);
+ }
+ return BinaryOperator::create(I.getOpcode(), Op0, Op1);
+ }
+
+ // Handle the special case of: setcc (cast bool to X), <cst>
+ // This comes up when you have code like
+ // int X = A < B;
+ // if (X) ...
+ // For generality, we handle any zero-extension of any operand comparison
+ // with a constant.
+ if (ConstantInt *ConstantRHS = dyn_cast<ConstantInt>(Op1)) {
+ const Type *SrcTy = CastOp0->getType();
+ const Type *DestTy = Op0->getType();
+ if (SrcTy->getPrimitiveSize() < DestTy->getPrimitiveSize() &&
+ (SrcTy->isUnsigned() || SrcTy == Type::BoolTy)) {
+ // Ok, we have an expansion of operand 0 into a new type. Get the
+ // constant value, masink off bits which are not set in the RHS. These
+ // could be set if the destination value is signed.
+ uint64_t ConstVal = ConstantRHS->getRawValue();
+ ConstVal &= (1ULL << DestTy->getPrimitiveSize()*8)-1;
+
+ // If the constant we are comparing it with has high bits set, which
+ // don't exist in the original value, the values could never be equal,
+ // because the source would be zero extended.
+ unsigned SrcBits =
+ SrcTy == Type::BoolTy ? 1 : SrcTy->getPrimitiveSize()*8;
+ bool HasSignBit = ConstVal & (1ULL << (DestTy->getPrimitiveSize()*8-1));
+ if (ConstVal & ~((1ULL << SrcBits)-1)) {
+ switch (I.getOpcode()) {
+ default: assert(0 && "Unknown comparison type!");
+ case Instruction::SetEQ:
+ return ReplaceInstUsesWith(I, ConstantBool::False);
+ case Instruction::SetNE:
+ return ReplaceInstUsesWith(I, ConstantBool::True);
+ case Instruction::SetLT:
+ case Instruction::SetLE:
+ if (DestTy->isSigned() && HasSignBit)
+ return ReplaceInstUsesWith(I, ConstantBool::False);
+ return ReplaceInstUsesWith(I, ConstantBool::True);
+ case Instruction::SetGT:
+ case Instruction::SetGE:
+ if (DestTy->isSigned() && HasSignBit)
+ return ReplaceInstUsesWith(I, ConstantBool::True);
+ return ReplaceInstUsesWith(I, ConstantBool::False);
+ }
+ }
+
+ // Otherwise, we can replace the setcc with a setcc of the smaller
+ // operand value.
+ Op1 = ConstantExpr::getCast(cast<Constant>(Op1), SrcTy);
+ return BinaryOperator::create(I.getOpcode(), CastOp0, Op1);
+ }
+ }
+ }
return Changed ? &I : 0;
}
// of a signed value.
//
unsigned TypeBits = Op0->getType()->getPrimitiveSize()*8;
- if (CUI->getValue() >= TypeBits &&
- (!Op0->getType()->isSigned() || isLeftShift))
- return ReplaceInstUsesWith(I, Constant::getNullValue(Op0->getType()));
+ if (CUI->getValue() >= TypeBits) {
+ if (!Op0->getType()->isSigned() || isLeftShift)
+ return ReplaceInstUsesWith(I, Constant::getNullValue(Op0->getType()));
+ else {
+ I.setOperand(1, ConstantUInt::get(Type::UByteTy, TypeBits-1));
+ return &I;
+ }
+ }
// ((X*C1) << C2) == (X * (C1 << C2))
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0))
if (BO->getOpcode() == Instruction::Mul && isLeftShift)
if (Constant *BOOp = dyn_cast<Constant>(BO->getOperand(1)))
return BinaryOperator::create(Instruction::Mul, BO->getOperand(0),
- *BOOp << *CUI);
+ ConstantExpr::get(Instruction::Shl, BOOp, CUI));
// If the operand is an bitwise operator with a constant RHS, and the
// shift is the only use, we can pull it out of the shift.
- if (Op0->use_size() == 1)
+ if (Op0->hasOneUse())
if (BinaryOperator *Op0BO = dyn_cast<BinaryOperator>(Op0))
if (ConstantInt *Op0C = dyn_cast<ConstantInt>(Op0BO->getOperand(1))) {
bool isValid = true; // Valid only for And, Or, Xor
}
if (isValid) {
- Constant *NewRHS =
- ConstantFoldShiftInstruction(I.getOpcode(), Op0C, CUI);
+ Constant *NewRHS = ConstantExpr::get(I.getOpcode(), Op0C, CUI);
Instruction *NewShift =
new ShiftInst(I.getOpcode(), Op0BO->getOperand(0), CUI,
// Check for (A << c1) << c2 and (A >> c1) >> c2
if (I.getOpcode() == Op0SI->getOpcode()) {
unsigned Amt = ShiftAmt1+ShiftAmt2; // Fold into one big shift...
+ if (Op0->getType()->getPrimitiveSize()*8 < Amt)
+ Amt = Op0->getType()->getPrimitiveSize()*8;
return new ShiftInst(I.getOpcode(), Op0SI->getOperand(0),
ConstantUInt::get(Type::UByteTy, Amt));
}
// Calculate bitmask for what gets shifted off the edge...
Constant *C = ConstantIntegral::getAllOnesValue(I.getType());
if (isLeftShift)
- C = ConstantExpr::getShift(Instruction::Shl, C, ShiftAmt1C);
+ C = ConstantExpr::get(Instruction::Shl, C, ShiftAmt1C);
else
- C = ConstantExpr::getShift(Instruction::Shr, C, ShiftAmt1C);
+ C = ConstantExpr::get(Instruction::Shr, C, ShiftAmt1C);
Instruction *Mask =
BinaryOperator::create(Instruction::And, Op0SI->getOperand(0),
}
}
+ // If we are casting a malloc or alloca to a pointer to a type of the same
+ // size, rewrite the allocation instruction to allocate the "right" type.
+ //
+ if (AllocationInst *AI = dyn_cast<AllocationInst>(Src))
+ if (AI->hasOneUse() && !AI->isArrayAllocation())
+ if (const PointerType *PTy = dyn_cast<PointerType>(CI.getType())) {
+ // Get the type really allocated and the type casted to...
+ const Type *AllocElTy = AI->getAllocatedType();
+ unsigned AllocElTySize = TD->getTypeSize(AllocElTy);
+ const Type *CastElTy = PTy->getElementType();
+ unsigned CastElTySize = TD->getTypeSize(CastElTy);
+
+ // If the allocation is for an even multiple of the cast type size
+ if (CastElTySize && (AllocElTySize % CastElTySize == 0)) {
+ Value *Amt = ConstantUInt::get(Type::UIntTy,
+ AllocElTySize/CastElTySize);
+ std::string Name = AI->getName(); AI->setName("");
+ AllocationInst *New;
+ if (isa<MallocInst>(AI))
+ New = new MallocInst(CastElTy, Amt, Name);
+ else
+ New = new AllocaInst(CastElTy, Amt, Name);
+ InsertNewInstBefore(New, CI);
+ return ReplaceInstUsesWith(CI, New);
+ }
+ }
+
// If the source value is an instruction with only this use, we can attempt to
// propagate the cast into the instruction. Also, only handle integral types
// for now.
if (Instruction *SrcI = dyn_cast<Instruction>(Src))
- if (SrcI->use_size() == 1 && Src->getType()->isIntegral() &&
+ if (SrcI->hasOneUse() && Src->getType()->isIntegral() &&
CI.getType()->isInteger()) { // Don't mess with casts to bool here
const Type *DestTy = CI.getType();
unsigned SrcBitSize = getTypeSizeInBits(Src->getType());
return visitCallSite(&II);
}
-// getPromotedType - Return the specified type promoted as it would be to pass
-// though a va_arg area...
-static const Type *getPromotedType(const Type *Ty) {
- switch (Ty->getPrimitiveID()) {
- case Type::SByteTyID:
- case Type::ShortTyID: return Type::IntTy;
- case Type::UByteTyID:
- case Type::UShortTyID: return Type::UIntTy;
- case Type::FloatTyID: return Type::DoubleTy;
- default: return Ty;
- }
-}
-
// visitCallSite - Improvements for call and invoke instructions.
//
Instruction *InstCombiner::visitCallSite(CallSite CS) {
const FunctionType *FT = Callee->getFunctionType();
const Type *OldRetTy = Caller->getType();
- if (Callee->isExternal() &&
- !OldRetTy->isLosslesslyConvertibleTo(FT->getReturnType()))
- return false; // Cannot transform this return value...
+ // Check to see if we are changing the return type...
+ if (OldRetTy != FT->getReturnType()) {
+ if (Callee->isExternal() &&
+ !OldRetTy->isLosslesslyConvertibleTo(FT->getReturnType()) &&
+ !Caller->use_empty())
+ return false; // Cannot transform this return value...
+
+ // If the callsite is an invoke instruction, and the return value is used by
+ // a PHI node in a successor, we cannot change the return type of the call
+ // because there is no place to put the cast instruction (without breaking
+ // the critical edge). Bail out in this case.
+ if (!Caller->use_empty())
+ if (InvokeInst *II = dyn_cast<InvokeInst>(Caller))
+ for (Value::use_iterator UI = II->use_begin(), E = II->use_end();
+ UI != E; ++UI)
+ if (PHINode *PN = dyn_cast<PHINode>(*UI))
+ if (PN->getParent() == II->getNormalDest() ||
+ PN->getParent() == II->getUnwindDest())
+ return false;
+ }
unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin());
unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
Instruction *NC;
if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
- NC = new InvokeInst(Callee, II->getNormalDest(), II->getExceptionalDest(),
+ NC = new InvokeInst(Callee, II->getNormalDest(), II->getUnwindDest(),
Args, Caller->getName(), Caller);
} else {
NC = new CallInst(Callee, Args, Caller->getName(), Caller);
if (Caller->getType() != NV->getType() && !Caller->use_empty()) {
if (NV->getType() != Type::VoidTy) {
NV = NC = new CastInst(NC, Caller->getType(), "tmp");
- InsertNewInstBefore(NC, *Caller);
+
+ // If this is an invoke instruction, we should insert it after the first
+ // non-phi, instruction in the normal successor block.
+ if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
+ BasicBlock::iterator I = II->getNormalDest()->begin();
+ while (isa<PHINode>(I)) ++I;
+ InsertNewInstBefore(NC, *I);
+ } else {
+ // Otherwise, it's a call, just insert cast right after the call instr
+ InsertNewInstBefore(NC, *Caller);
+ }
AddUsesToWorkList(*Caller);
} else {
NV = Constant::getNullValue(Caller->getType());
// PHINode simplification
//
Instruction *InstCombiner::visitPHINode(PHINode &PN) {
- // If the PHI node only has one incoming value, eliminate the PHI node...
- if (PN.getNumIncomingValues() == 1)
- return ReplaceInstUsesWith(PN, PN.getIncomingValue(0));
-
- // Otherwise if all of the incoming values are the same for the PHI, replace
- // the PHI node with the incoming value.
- //
- Value *InVal = 0;
- for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i)
- if (PN.getIncomingValue(i) != &PN) // Not the PHI node itself...
- if (InVal && PN.getIncomingValue(i) != InVal)
- return 0; // Not the same, bail out.
- else
- InVal = PN.getIncomingValue(i);
-
- // The only case that could cause InVal to be null is if we have a PHI node
- // that only has entries for itself. In this case, there is no entry into the
- // loop, so kill the PHI.
- //
- if (InVal == 0) InVal = Constant::getNullValue(PN.getType());
+ if (Value *V = hasConstantValue(&PN))
+ return ReplaceInstUsesWith(PN, V);
+
+ // If the only user of this instruction is a cast instruction, and all of the
+ // incoming values are constants, change this PHI to merge together the casted
+ // constants.
+ if (PN.hasOneUse())
+ if (CastInst *CI = dyn_cast<CastInst>(PN.use_back()))
+ if (CI->getType() != PN.getType()) { // noop casts will be folded
+ bool AllConstant = true;
+ for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i)
+ if (!isa<Constant>(PN.getIncomingValue(i))) {
+ AllConstant = false;
+ break;
+ }
+ if (AllConstant) {
+ // Make a new PHI with all casted values.
+ PHINode *New = new PHINode(CI->getType(), PN.getName(), &PN);
+ for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
+ Constant *OldArg = cast<Constant>(PN.getIncomingValue(i));
+ New->addIncoming(ConstantExpr::getCast(OldArg, New->getType()),
+ PN.getIncomingBlock(i));
+ }
- // All of the incoming values are the same, replace the PHI node now.
- return ReplaceInstUsesWith(PN, InVal);
+ // Update the cast instruction.
+ CI->setOperand(0, New);
+ WorkList.push_back(CI); // revisit the cast instruction to fold.
+ WorkList.push_back(New); // Make sure to revisit the new Phi
+ return &PN; // PN is now dead!
+ }
+ }
+ return 0;
}
Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
// Is it 'getelementptr %P, long 0' or 'getelementptr %P'
// If so, eliminate the noop.
- if ((GEP.getNumOperands() == 2 &&
- GEP.getOperand(1) == Constant::getNullValue(Type::LongTy)) ||
- GEP.getNumOperands() == 1)
+ if (GEP.getNumOperands() == 1)
+ return ReplaceInstUsesWith(GEP, GEP.getOperand(0));
+
+ bool HasZeroPointerIndex = false;
+ if (Constant *C = dyn_cast<Constant>(GEP.getOperand(1)))
+ HasZeroPointerIndex = C->isNullValue();
+
+ if (GEP.getNumOperands() == 2 && HasZeroPointerIndex)
return ReplaceInstUsesWith(GEP, GEP.getOperand(0));
// Combine Indices - If the source pointer to this getelementptr instruction
// Replace all uses of the GEP with the new constexpr...
return ReplaceInstUsesWith(GEP, CE);
}
+ } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(GEP.getOperand(0))) {
+ if (CE->getOpcode() == Instruction::Cast) {
+ if (HasZeroPointerIndex) {
+ // transform: GEP (cast [10 x ubyte]* X to [0 x ubyte]*), long 0, ...
+ // into : GEP [10 x ubyte]* X, long 0, ...
+ //
+ // This occurs when the program declares an array extern like "int X[];"
+ //
+ Constant *X = CE->getOperand(0);
+ const PointerType *CPTy = cast<PointerType>(CE->getType());
+ if (const PointerType *XTy = dyn_cast<PointerType>(X->getType()))
+ if (const ArrayType *XATy =
+ dyn_cast<ArrayType>(XTy->getElementType()))
+ if (const ArrayType *CATy =
+ dyn_cast<ArrayType>(CPTy->getElementType()))
+ if (CATy->getElementType() == XATy->getElementType()) {
+ // At this point, we know that the cast source type is a pointer
+ // to an array of the same type as the destination pointer
+ // array. Because the array type is never stepped over (there
+ // is a leading zero) we can fold the cast into this GEP.
+ GEP.setOperand(0, X);
+ return &GEP;
+ }
+ }
+ }
}
return 0;
return 0;
}
+Instruction *InstCombiner::visitFreeInst(FreeInst &FI) {
+ Value *Op = FI.getOperand(0);
+
+ // Change free <ty>* (cast <ty2>* X to <ty>*) into free <ty2>* X
+ if (CastInst *CI = dyn_cast<CastInst>(Op))
+ if (isa<PointerType>(CI->getOperand(0)->getType())) {
+ FI.setOperand(0, CI->getOperand(0));
+ return &FI;
+ }
+
+ return 0;
+}
+
+
/// GetGEPGlobalInitializer - Given a constant, and a getelementptr
/// constantexpr, return the constant value being addressed by the constant
/// expression, or null if something is funny.
// addressing...
for (unsigned i = 2, e = CE->getNumOperands(); i != e; ++i)
if (ConstantUInt *CU = dyn_cast<ConstantUInt>(CE->getOperand(i))) {
- ConstantStruct *CS = cast<ConstantStruct>(C);
+ ConstantStruct *CS = dyn_cast<ConstantStruct>(C);
+ if (CS == 0) return 0;
if (CU->getValue() >= CS->getValues().size()) return 0;
C = cast<Constant>(CS->getValues()[CU->getValue()]);
} else if (ConstantSInt *CS = dyn_cast<ConstantSInt>(CE->getOperand(i))) {
- ConstantArray *CA = cast<ConstantArray>(C);
+ ConstantArray *CA = dyn_cast<ConstantArray>(C);
+ if (CA == 0) return 0;
if ((uint64_t)CS->getValue() >= CA->getValues().size()) return 0;
C = cast<Constant>(CA->getValues()[CS->getValue()]);
} else
Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
Value *Op = LI.getOperand(0);
+ if (LI.isVolatile()) return 0;
+
if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(Op))
Op = CPR->getValue();
bool InstCombiner::runOnFunction(Function &F) {
bool Changed = false;
+ TD = &getAnalysis<TargetData>();
WorkList.insert(WorkList.end(), inst_begin(F), inst_end(F));
return Changed;
}
-Pass *createInstructionCombiningPass() {
+Pass *llvm::createInstructionCombiningPass() {
return new InstCombiner();
}
+
projects / oota-llvm.git / blobdiff