Index: clang/include/clang/AST/ASTContext.h
===================================================================
--- clang/include/clang/AST/ASTContext.h
+++ clang/include/clang/AST/ASTContext.h
@@ -249,6 +249,8 @@
                                      ASTContext&>
     SubstTemplateTemplateParmPacks;
 
+  mutable llvm::DenseMap<unsigned, APValue> ExprEvalResultCache;
+
   /// The set of nested name specifiers.
   ///
   /// This set is managed by the NestedNameSpecifier class.
@@ -2527,6 +2529,8 @@
 
   /// Determine whether the given expressions \p X and \p Y are equivalent.
   bool hasSameExpr(const Expr *X, const Expr *Y) const;
+  bool getCachedEvaluated(const Expr *X, APValue &Result) const;
+  void addExprResultToCache(const Expr *X, APValue &Result) const;
 
   /// Return this type as a completely-unqualified array type,
   /// capturing the qualifiers in \p Quals.
Index: clang/lib/AST/ASTContext.cpp
===================================================================
--- clang/lib/AST/ASTContext.cpp
+++ clang/lib/AST/ASTContext.cpp
@@ -40,6 +40,7 @@
 #include "clang/AST/ParentMapContext.h"
 #include "clang/AST/RawCommentList.h"
 #include "clang/AST/RecordLayout.h"
+#include "clang/AST/ODRHash.h"
 #include "clang/AST/Stmt.h"
 #include "clang/AST/TemplateBase.h"
 #include "clang/AST/TemplateName.h"
@@ -12385,6 +12386,52 @@
   return IDX == IDY;
 }
 
+bool ASTContext::getCachedEvaluated(const Expr *X, APValue &Result) const {
+  assert (X && "We shouldn't evaluate on null expr.\n");
+
+  auto *CE = dyn_cast<CallExpr>(X);
+  if (!CE)
+    return false;
+  
+  auto *FD = CE->getDirectCallee();
+  if (!FD || !FD->isConstexpr())
+    return false;
+
+  llvm::FoldingSetNodeID ID;
+  X->Profile(ID, *this, /*Canonical=*/true);
+  unsigned HashValue = llvm::hash_combine(ID.ComputeHash(), const_cast<FunctionDecl*>(FD)->getODRHash());
+
+  auto Iter = ExprEvalResultCache.find(HashValue);
+  if (Iter == ExprEvalResultCache.end())
+    return false;
+
+  Result = Iter->second;
+  assert(Result.hasValue());
+  return true;
+}
+
+void ASTContext::addExprResultToCache(const Expr *X, APValue &Result) const {
+  if (!Result.hasValue())
+    return;
+
+  auto *CE = dyn_cast<CallExpr>(X);
+  if (!CE)
+    return;
+  
+  auto *FD = CE->getDirectCallee();
+  if (!FD || !FD->isConstexpr())
+    return;
+
+  assert (X && "We shouldn't evaluate on null expr.\n");
+  llvm::FoldingSetNodeID ID;
+  X->Profile(ID, *this, /*Canonical=*/true);
+  unsigned HashValue = llvm::hash_combine(ID.ComputeHash(), const_cast<FunctionDecl*>(FD)->getODRHash());
+
+  auto Iter = ExprEvalResultCache.find(HashValue);
+  assert(Iter == ExprEvalResultCache.end());
+  ExprEvalResultCache.insert({HashValue, Result});
+}
+
 // The getCommon* helpers return, for given 'same' X and Y entities given as
 // inputs, another entity which is also the 'same' as the inputs, but which
 // is closer to the canonical form of the inputs, each according to a given
Index: clang/lib/AST/ExprConstant.cpp
===================================================================
--- clang/lib/AST/ExprConstant.cpp
+++ clang/lib/AST/ExprConstant.cpp
@@ -15412,6 +15412,11 @@
   SourceLocation DeclLoc = VD->getLocation();
   QualType DeclTy = VD->getType();
 
+  if (Ctx.getCachedEvaluated(this, Value))
+    return CheckConstantExpression(Info, DeclLoc, DeclTy, Value,
+                                 ConstantExprKind::Normal) &&
+           CheckMemoryLeaks(Info);
+
   if (Info.EnableNewConstInterp) {
     auto &InterpCtx = const_cast<ASTContext &>(Ctx).getInterpContext();
     if (!InterpCtx.evaluateAsInitializer(Info, VD, Value))
@@ -15432,9 +15437,14 @@
     if (!Info.discardCleanups())
       llvm_unreachable("Unhandled cleanup; missing full expression marker?");
   }
-  return CheckConstantExpression(Info, DeclLoc, DeclTy, Value,
+  auto Ret = CheckConstantExpression(Info, DeclLoc, DeclTy, Value,
                                  ConstantExprKind::Normal) &&
          CheckMemoryLeaks(Info);
+
+  if (Ret && Value.hasValue())
+    Ctx.addExprResultToCache(this, Value);
+
+  return Ret;
 }
 
 bool VarDecl::evaluateDestruction(