From b474372d7b052b50f24dea13719673711c677c7d Mon Sep 17 00:00:00 2001
From: Rahul Joshi <jurahul@google.com>
Date: Mon, 15 Jun 2020 18:25:14 +0000
Subject: [PATCH] [LLVM] Change isa<> to a variadic function template

Change isa<> to a variadic function template, so that it can be used to test against one of multiple types as follows:
   isa<Type0, Type1, Type2>(Val)

Differential Revision: https://reviews.llvm.org/D81045
---
 include/llvm/Support/Casting.h         | 14 ++++++++++----
 lib/Analysis/ScalarEvolution.cpp       |  6 ++++--
 lib/Target/PowerPC/PPCBoolRetToInt.cpp |  2 +-
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/include/llvm/Support/Casting.h b/include/llvm/Support/Casting.h
index 41f1b6740c6..d6f7793d5df 100644
--- a/include/llvm/Support/Casting.h
+++ b/include/llvm/Support/Casting.h
@@ -132,24 +132,30 @@ struct isa_impl_wrap<To, FromTy, FromTy> {
   }
 };
 
-// isa<X> - Return true if the parameter to the template is an instance of the
-// template type argument.  Used like this:
+// isa<X> - Return true if the parameter to the template is an instance of one
+// of the template type arguments.  Used like this:
 //
 //  if (isa<Type>(myVal)) { ... }
+//  if (isa<Type0, Type1, Type2>(myVal)) { ... }
 //
 template <class X, class Y> LLVM_NODISCARD inline bool isa(const Y &Val) {
   return isa_impl_wrap<X, const Y,
                        typename simplify_type<const Y>::SimpleType>::doit(Val);
 }
 
+template <typename First, typename Second, typename... Rest, typename Y>
+LLVM_NODISCARD inline bool isa(const Y &Val) {
+  return isa<First>(Val) || isa<Second, Rest...>(Val);
+}
+
 // isa_and_nonnull<X> - Functionally identical to isa, except that a null value
 // is accepted.
 //
-template <class X, class Y>
+template <typename... X, class Y>
 LLVM_NODISCARD inline bool isa_and_nonnull(const Y &Val) {
   if (!Val)
     return false;
-  return isa<X>(Val);
+  return isa<X...>(Val);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 85f9794aa8d..3625b5e4203 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -3860,7 +3860,8 @@ bool ScalarEvolution::containsAddRecurrence(const SCEV *S) {
   if (I != HasRecMap.end())
     return I->second;
 
-  bool FoundAddRec = SCEVExprContains(S, isa<SCEVAddRecExpr, const SCEV *>);
+  bool FoundAddRec =
+      SCEVExprContains(S, [](const SCEV *S) { return isa<SCEVAddRecExpr>(S); });
   HasRecMap.insert({S, FoundAddRec});
   return FoundAddRec;
 }
@@ -11201,8 +11202,9 @@ static bool findArrayDimensionsRec(ScalarEvolution &SE,
 // Returns true when one of the SCEVs of Terms contains a SCEVUnknown parameter.
 static inline bool containsParameters(SmallVectorImpl<const SCEV *> &Terms) {
   for (const SCEV *T : Terms)
-    if (SCEVExprContains(T, isa<SCEVUnknown, const SCEV *>))
+    if (SCEVExprContains(T, [](const SCEV *S) { return isa<SCEVUnknown>(S); }))
       return true;
+
   return false;
 }
 
diff --git a/lib/Target/PowerPC/PPCBoolRetToInt.cpp b/lib/Target/PowerPC/PPCBoolRetToInt.cpp
index 104cf2ba3c0..2259a29f838 100644
--- a/lib/Target/PowerPC/PPCBoolRetToInt.cpp
+++ b/lib/Target/PowerPC/PPCBoolRetToInt.cpp
@@ -220,7 +220,7 @@ class PPCBoolRetToInt : public FunctionPass {
     auto Defs = findAllDefs(U);
 
     // If the values are all Constants or Arguments, don't bother
-    if (llvm::none_of(Defs, isa<Instruction, Value *>))
+    if (llvm::none_of(Defs, [](Value *V) { return isa<Instruction>(V); }))
       return false;
 
     // Presently, we only know how to handle PHINode, Constant, Arguments and