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modify CheckGEPInstructions to take a pointer and size instead of a vector. 

llvm-svn: 34166
This commit is contained in:
Chris Lattner 2007-02-10 22:12:53 +00:00
parent d63a5200cb
commit 237b5b60ea
1 changed files with 31 additions and 23 deletions
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54
llvm/lib/Analysis/BasicAliasAnalysis.cpp
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@ -111,10 +111,10 @@ namespace {
// must-aliasing base pointers. This checks to see if the index expressions
// preclude the pointers from aliasing...
AliasResult
CheckGEPInstructions(const Type* BasePtr1Ty, std::vector<Value*> &GEP1Ops,
unsigned G1Size,
const Type *BasePtr2Ty, std::vector<Value*> &GEP2Ops,
unsigned G2Size);
CheckGEPInstructions(const Type* BasePtr1Ty,
Value **GEP1Ops, unsigned NumGEP1Ops, unsigned G1Size,
const Type *BasePtr2Ty,
Value **GEP2Ops, unsigned NumGEP2Ops, unsigned G2Size);
};
// Register this pass...
@ -377,8 +377,10 @@ BasicAliasAnalysis::alias(const Value *V1, unsigned V1Size,
// do the comparison.
if (BasePtr1 == BasePtr2) {
AliasResult GAlias =
CheckGEPInstructions(BasePtr1->getType(), GEP1Ops, V1Size,
BasePtr2->getType(), GEP2Ops, V2Size);
CheckGEPInstructions(BasePtr1->getType(),
&GEP1Ops[0], GEP1Ops.size(), V1Size,
BasePtr2->getType(),
&GEP2Ops[0], GEP2Ops.size(), V2Size);
if (GAlias != MayAlias)
return GAlias;
}
@ -472,8 +474,8 @@ static bool IndexOperandsEqual(Value *V1, Value *V2) {
/// pointers from aliasing...
AliasAnalysis::AliasResult
BasicAliasAnalysis::CheckGEPInstructions(
const Type* BasePtr1Ty, std::vector<Value*> &GEP1Ops, unsigned G1S,
const Type *BasePtr2Ty, std::vector<Value*> &GEP2Ops, unsigned G2S) {
const Type* BasePtr1Ty, Value **GEP1Ops, unsigned NumGEP1Ops, unsigned G1S,
const Type *BasePtr2Ty, Value **GEP2Ops, unsigned NumGEP2Ops, unsigned G2S) {
// We currently can't handle the case when the base pointers have different
// primitive types. Since this is uncommon anyway, we are happy being
// extremely conservative.
@ -484,7 +486,7 @@ BasicAliasAnalysis::CheckGEPInstructions(
// Find the (possibly empty) initial sequence of equal values... which are not
// necessarily constants.
unsigned NumGEP1Operands = GEP1Ops.size(), NumGEP2Operands = GEP2Ops.size();
unsigned NumGEP1Operands = NumGEP1Ops, NumGEP2Operands = NumGEP2Ops;
unsigned MinOperands = std::min(NumGEP1Operands, NumGEP2Operands);
unsigned MaxOperands = std::max(NumGEP1Operands, NumGEP2Operands);
unsigned UnequalOper = 0;
@ -508,7 +510,10 @@ BasicAliasAnalysis::CheckGEPInstructions(
// getelementptrs, check to see if the tail of the leftover one is all zeros.
// If so, return mustalias.
if (UnequalOper == MinOperands) {
if (GEP1Ops.size() < GEP2Ops.size()) std::swap(GEP1Ops, GEP2Ops);
if (NumGEP1Ops < NumGEP2Ops) {
std::swap(GEP1Ops, GEP2Ops);
std::swap(NumGEP1Ops, NumGEP2Ops);
}
bool AllAreZeros = true;
for (unsigned i = UnequalOper; i != MaxOperands; ++i)
@ -585,8 +590,10 @@ BasicAliasAnalysis::CheckGEPInstructions(
Constant *Compare = ConstantExpr::getICmp(ICmpInst::ICMP_SGT,
G1OC, G2OC);
if (ConstantInt *CV = dyn_cast<ConstantInt>(Compare)) {
if (CV->getZExtValue()) // If they are comparable and G2 > G1
if (CV->getZExtValue()) { // If they are comparable and G2 > G1
std::swap(GEP1Ops, GEP2Ops); // Make GEP1 < GEP2
std::swap(NumGEP1Ops, NumGEP2Ops);
}
break;
}
}
@ -602,11 +609,13 @@ BasicAliasAnalysis::CheckGEPInstructions(
// case, there may still be hope. Check this now.
if (FirstConstantOper == MinOperands) {
// Make GEP1Ops be the longer one if there is a longer one.
if (GEP1Ops.size() < GEP2Ops.size())
if (NumGEP1Ops < NumGEP2Ops) {
std::swap(GEP1Ops, GEP2Ops);
std::swap(NumGEP1Ops, NumGEP2Ops);
}
// Is there anything to check?
if (GEP1Ops.size() > MinOperands) {
if (NumGEP1Ops > MinOperands) {
for (unsigned i = FirstConstantOper; i != MaxOperands; ++i)
if (isa<ConstantInt>(GEP1Ops[i]) &&
!cast<Constant>(GEP1Ops[i])->isNullValue()) {
@ -619,13 +628,12 @@ BasicAliasAnalysis::CheckGEPInstructions(
// Okay, now get the offset. This is the relative offset for the full
// instruction.
const TargetData &TD = getTargetData();
int64_t Offset1 = TD.getIndexedOffset(GEPPointerTy, &GEP1Ops[0],
GEP1Ops.size());
int64_t Offset1 = TD.getIndexedOffset(GEPPointerTy, GEP1Ops,
NumGEP1Ops);
// Now crop off any constants from the end...
GEP1Ops.resize(MinOperands);
int64_t Offset2 = TD.getIndexedOffset(GEPPointerTy, &GEP1Ops[0],
GEP1Ops.size());
// Now check without any constants at the end.
int64_t Offset2 = TD.getIndexedOffset(GEPPointerTy, GEP1Ops,
MinOperands);
// If the tail provided a bit enough offset, return noalias!
if ((uint64_t)(Offset2-Offset1) >= SizeMax)
@ -665,8 +673,8 @@ BasicAliasAnalysis::CheckGEPInstructions(
// Loop over the rest of the operands...
for (unsigned i = FirstConstantOper+1; i != MaxOperands; ++i) {
const Value *Op1 = i < GEP1Ops.size() ? GEP1Ops[i] : 0;
const Value *Op2 = i < GEP2Ops.size() ? GEP2Ops[i] : 0;
const Value *Op1 = i < NumGEP1Ops ? GEP1Ops[i] : 0;
const Value *Op2 = i < NumGEP2Ops ? GEP2Ops[i] : 0;
// If they are equal, use a zero index...
if (Op1 == Op2 && BasePtr1Ty == BasePtr2Ty) {
if (!isa<ConstantInt>(Op1))
@ -736,9 +744,9 @@ BasicAliasAnalysis::CheckGEPInstructions(
if (GEPPointerTy->getElementType()->isSized()) {
int64_t Offset1 =
getTargetData().getIndexedOffset(GEPPointerTy,&GEP1Ops[0],GEP1Ops.size());
getTargetData().getIndexedOffset(GEPPointerTy, GEP1Ops, NumGEP1Ops);
int64_t Offset2 =
getTargetData().getIndexedOffset(GEPPointerTy,&GEP2Ops[0],GEP2Ops.size());
getTargetData().getIndexedOffset(GEPPointerTy, GEP2Ops, NumGEP2Ops);
assert(Offset1<Offset2 && "There is at least one different constant here!");
if ((uint64_t)(Offset2-Offset1) >= SizeMax) {