[NFC][Load] Find better place for mustSuppressSpeculation

And extract `suppressSpeculativeLoadForSanitizers`.

Pull Request: #100794

Author: vitalybuka

llvm/include/llvm/Analysis/Loads.h

@@ -106,6 +106,13 @@ bool isSafeToLoadUnconditionally(Value *V, Type *Ty, Align Alignment,
                                  const DominatorTree *DT = nullptr,
                                  const TargetLibraryInfo *TLI = nullptr);
 
+/// Return true if speculation of the given load must be suppressed to avoid
+/// ordering or interfering with an active sanitizer.  If not suppressed,
+/// dereferenceability and alignment must be proven separately.  Note: This
+/// is only needed for raw reasoning; if you use the interface below
+/// (isSafeToSpeculativelyExecute), this is handled internally.
+bool mustSuppressSpeculation(const LoadInst &LI);
+
 /// The default number of maximum instructions to scan in the block, used by
 /// FindAvailableLoadedValue().
 extern cl::opt<unsigned> DefMaxInstsToScan;

llvm/include/llvm/Analysis/ValueTracking.h

@@ -792,13 +792,6 @@ bool onlyUsedByLifetimeMarkers(const Value *V);
 /// droppable instructions.
 bool onlyUsedByLifetimeMarkersOrDroppableInsts(const Value *V);
 
-/// Return true if speculation of the given load must be suppressed to avoid
-/// ordering or interfering with an active sanitizer.  If not suppressed,
-/// dereferenceability and alignment must be proven separately.  Note: This
-/// is only needed for raw reasoning; if you use the interface below
-/// (isSafeToSpeculativelyExecute), this is handled internally.
-bool mustSuppressSpeculation(const LoadInst &LI);
-
 /// Return true if the instruction does not have any effects besides
 /// calculating the result and does not have undefined behavior.
 ///

llvm/lib/Analysis/Loads.cpp

@@ -345,6 +345,19 @@ bool llvm::isDereferenceableAndAlignedInLoop(LoadInst *LI, Loop *L,
                                             HeaderFirstNonPHI, AC, &DT);
 }
 
+static bool suppressSpeculativeLoadForSanitizers(const Instruction &CtxI) {
+  const Function &F = *CtxI.getFunction();
+  // Speculative load may create a race that did not exist in the source.
+  return F.hasFnAttribute(Attribute::SanitizeThread) ||
+         // Speculative load may load data from dirty regions.
+         F.hasFnAttribute(Attribute::SanitizeAddress) ||
+         F.hasFnAttribute(Attribute::SanitizeHWAddress);
+}
+
+bool llvm::mustSuppressSpeculation(const LoadInst &LI) {
+  return !LI.isUnordered() || suppressSpeculativeLoadForSanitizers(LI);
+}
+
 /// Check if executing a load of this pointer value cannot trap.
 ///
 /// If DT and ScanFrom are specified this method performs context-sensitive

llvm/lib/Analysis/ValueTracking.cpp

@@ -6798,17 +6798,6 @@ bool llvm::onlyUsedByLifetimeMarkersOrDroppableInsts(const Value *V) {
       V, /* AllowLifetime */ true, /* AllowDroppable */ true);
 }
 
-bool llvm::mustSuppressSpeculation(const LoadInst &LI) {
-  if (!LI.isUnordered())
-    return true;
-  const Function &F = *LI.getFunction();
-  // Speculative load may create a race that did not exist in the source.
-  return F.hasFnAttribute(Attribute::SanitizeThread) ||
-    // Speculative load may load data from dirty regions.
-    F.hasFnAttribute(Attribute::SanitizeAddress) ||
-    F.hasFnAttribute(Attribute::SanitizeHWAddress);
-}
-
 bool llvm::isSafeToSpeculativelyExecute(const Instruction *Inst,
                                         const Instruction *CtxI,
                                         AssumptionCache *AC,