[NFC][Load] Make ScanFrom required parameters

In #100773 we will go conservative for sanitizers,
so it's better to pinpoint location consciously.

Pull Request: #100789

Author: vitalybuka

llvm/include/llvm/Analysis/Loads.h

@@ -69,8 +69,7 @@ bool isDereferenceableAndAlignedPointer(const Value *V, Align Alignment,
 /// quick local scan of the basic block containing ScanFrom, to determine if
 /// the address is already accessed.
 bool isSafeToLoadUnconditionally(Value *V, Align Alignment, const APInt &Size,
-                                 const DataLayout &DL,
-                                 Instruction *ScanFrom = nullptr,
+                                 const DataLayout &DL, Instruction *ScanFrom,
                                  AssumptionCache *AC = nullptr,
                                  const DominatorTree *DT = nullptr,
                                  const TargetLibraryInfo *TLI = nullptr);
@@ -100,8 +99,7 @@ bool isDereferenceableReadOnlyLoop(Loop *L, ScalarEvolution *SE,
 /// quick local scan of the basic block containing ScanFrom, to determine if
 /// the address is already accessed.
 bool isSafeToLoadUnconditionally(Value *V, Type *Ty, Align Alignment,
-                                 const DataLayout &DL,
-                                 Instruction *ScanFrom = nullptr,
+                                 const DataLayout &DL, Instruction *ScanFrom,
                                  AssumptionCache *AC = nullptr,
                                  const DominatorTree *DT = nullptr,
                                  const TargetLibraryInfo *TLI = nullptr);

polly/lib/Analysis/ScopBuilder.cpp

@@ -2770,7 +2770,7 @@ isl::set ScopBuilder::getNonHoistableCtx(MemoryAccess *Access,
 
   auto &DL = scop->getFunction().getDataLayout();
   if (isSafeToLoadUnconditionally(LI->getPointerOperand(), LI->getType(),
-                                  LI->getAlign(), DL)) {
+                                  LI->getAlign(), DL, nullptr)) {
     SafeToLoad = isl::set::universe(AccessRelation.get_space().range());
   } else if (BB != LI->getParent()) {
     // Skip accesses in non-affine subregions as they might not be executed

polly/lib/Analysis/ScopDetection.cpp

@@ -490,7 +490,8 @@ bool ScopDetection::onlyValidRequiredInvariantLoads(
 
     for (auto NonAffineRegion : Context.NonAffineSubRegionSet) {
       if (isSafeToLoadUnconditionally(Load->getPointerOperand(),
-                                      Load->getType(), Load->getAlign(), DL))
+                                      Load->getType(), Load->getAlign(), DL,
+                                      nullptr))
         continue;
 
       if (NonAffineRegion->contains(Load) &&