/// rewrite expressions in canonical form.
///
/// Clients should create an instance of this class when rewriting is needed,
- /// and destroy it when finished to allow the release of the associated
+ /// and destroy it when finished to allow the release of the associated
/// memory.
struct SCEVExpander : public SCEVVisitor<SCEVExpander, Value*> {
ScalarEvolution &SE;
private:
LLVMContext &getContext() const { return SE.getContext(); }
-
+
/// InsertBinop - Insert the specified binary operator, doing a small amount
/// of work to avoid inserting an obviously redundant operation.
Value *InsertBinop(Instruction::BinaryOps Opcode, Value *LHS, Value *RHS);
}
#endif
-
"Computed GetElementPtr has unexpected type!");
// If we ended up indexing a member with a type that doesn't match
- // type type of what the original indices indexed, add a cast.
+ // the type of what the original indices indexed, add a cast.
if (Ty != cast<PointerType>(ResultTy)->getElementType())
C = ConstantExpr::getBitCast(C, ResultTy);
if (const SCEVConstant *RHSC = dyn_cast<SCEVConstant>(RHS)) {
if (RHSC->getValue()->equalsInt(1))
- return LHS; // X udiv 1 --> x
+ return LHS; // X udiv 1 --> x
if (RHSC->isZero())
return getIntegerSCEV(0, LHS->getType()); // value is undefined
if (!isa<SCEVCouldNotCompute>(TC)) return TC;
break;
}
- case ICmpInst::ICMP_EQ: {
- // Convert to: while (X-Y == 0) // while (X == Y)
+ case ICmpInst::ICMP_EQ: { // while (X == Y)
+ // Convert to: while (X-Y == 0)
const SCEV *TC = HowFarToNonZero(getMinusSCEV(LHS, RHS), L);
if (!isa<SCEVCouldNotCompute>(TC)) return TC;
break;
getContext());
else
C = ConstantFoldInstOperands(I->getOpcode(), I->getType(),
- &Operands[0], Operands.size(),
+ &Operands[0], Operands.size(),
getContext());
Pair.first->second = C;
return getSCEV(C);
// First, handle unitary steps.
if (StepC->getValue()->equalsInt(1)) // 1*N = -Start (mod 2^BW), so:
- return getNegativeSCEV(Start); // N = -Start (as unsigned)
+ return getNegativeSCEV(Start); // N = -Start (as unsigned)
if (StepC->getValue()->isAllOnesValue()) // -1*N = -Start (mod 2^BW), so:
return Start; // N = Start (as unsigned)
return CE->getOperand(0);
}
- // FIXME: keep track of the cast instruction.
if (Constant *C = dyn_cast<Constant>(V))
return ConstantExpr::getCast(Op, C, Ty);
-
+
if (Argument *A = dyn_cast<Argument>(V)) {
// Check to see if there is already a cast!
for (Value::use_iterator UI = A->use_begin(), E = A->use_end();
}
}
-/// expandAddToGEP - Expand a SCEVAddExpr with a pointer type into a GEP
-/// instead of using ptrtoint+arithmetic+inttoptr. This helps
-/// BasicAliasAnalysis and other passes analyze the result.
+/// expandAddToGEP - Expand an addition expression with a pointer type into
+/// a GEP instead of using ptrtoint+arithmetic+inttoptr. This helps
+/// BasicAliasAnalysis and other passes analyze the result. See the rules
+/// for getelementptr vs. inttoptr in
+/// http://llvm.org/docs/LangRef.html#pointeraliasing
+/// for details.
///
-/// Design note: This depends on ScalarEvolution not recognizing inttoptr
-/// and ptrtoint operators, as they may introduce pointer arithmetic
-/// which may not be safely converted into getelementptr.
+/// Design note: The correctness of using getelmeentptr here depends on
+/// ScalarEvolution not recognizing inttoptr and ptrtoint operators, as
+/// they may introduce pointer arithmetic which may not be safely converted
+/// into getelementptr.
///
/// Design note: It might seem desirable for this function to be more
/// loop-aware. If some of the indices are loop-invariant while others