Imported Upstream version 5.18.0.179

Former-commit-id: 67aa10e65b237e1c4537630979ee99ebe1374215

external/llvm/lib/Analysis/ValueLatticeUtils.cpp

@@ -0,0 +1,44 @@
+//===-- ValueLatticeUtils.cpp - Utils for solving lattices ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements common functions useful for performing data-flow
+// analyses that propagate values across function boundaries.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/ValueLatticeUtils.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Instructions.h"
+using namespace llvm;
+
+bool llvm::canTrackArgumentsInterprocedurally(Function *F) {
+  return F->hasLocalLinkage() && !F->hasAddressTaken();
+}
+
+bool llvm::canTrackReturnsInterprocedurally(Function *F) {
+  return F->hasExactDefinition() && !F->hasFnAttribute(Attribute::Naked);
+}
+
+bool llvm::canTrackGlobalVariableInterprocedurally(GlobalVariable *GV) {
+  if (GV->isConstant() || !GV->hasLocalLinkage() ||
+      !GV->hasDefinitiveInitializer())
+    return false;
+  return !any_of(GV->users(), [&](User *U) {
+    if (auto *Store = dyn_cast<StoreInst>(U)) {
+      if (Store->getValueOperand() == GV || Store->isVolatile())
+        return true;
+    } else if (auto *Load = dyn_cast<LoadInst>(U)) {
+      if (Load->isVolatile())
+        return true;
+    } else {
+      return true;
+    }
+    return false;
+  });
+}