[clang][Interp] Implement bitwise Or operations

Analogous to the bitAnd implementation, do the same for bitwise or.

Differential Revision: https://reviews.llvm.org/D135361

clang/lib/AST/Interp/ByteCodeExprGen.cpp

@@ -223,6 +223,7 @@ bool ByteCodeExprGen<Emitter>::VisitBinaryOperator(const BinaryOperator *BO) {
     case BO_And:
       return Discard(this->emitBitAnd(*T, BO));
     case BO_Or:
+      return Discard(this->emitBitOr(*T, BO));
     case BO_LAnd:
     case BO_LOr:
     default:

clang/lib/AST/Interp/Integral.h

@@ -222,6 +222,11 @@ template <unsigned Bits, bool Signed> class Integral final {
     return false;
   }
 
+  static bool bitOr(Integral A, Integral B, unsigned OpBits, Integral *R) {
+    *R = Integral(A.V | B.V);
+    return false;
+  }
+
   static bool neg(Integral A, Integral *R) {
     *R = -A;
     return false;

clang/lib/AST/Interp/Interp.h

@@ -170,6 +170,23 @@ bool BitAnd(InterpState &S, CodePtr OpPC) {
   return false;
 }
 
+/// 1) Pops the RHS from the stack.
+/// 2) Pops the LHS from the stack.
+/// 3) Pushes 'LHS | RHS' on the stack
+template <PrimType Name, class T = typename PrimConv<Name>::T>
+bool BitOr(InterpState &S, CodePtr OpPC) {
+  const T &RHS = S.Stk.pop<T>();
+  const T &LHS = S.Stk.pop<T>();
+
+  unsigned Bits = RHS.bitWidth();
+  T Result;
+  if (!T::bitOr(LHS, RHS, Bits, &Result)) {
+    S.Stk.push<T>(Result);
+    return true;
+  }
+  return false;
+}
+
 /// 1) Pops the RHS from the stack.
 /// 2) Pops the LHS from the stack.
 /// 3) Pushes 'LHS % RHS' on the stack (the remainder of dividing LHS by RHS).

clang/lib/AST/Interp/Opcodes.td

@@ -412,6 +412,7 @@ def Rem : Opcode {
   let HasGroup = 1;
 }
 def BitAnd : IntegerOpcode;
+def BitOr : IntegerOpcode;
 def Div : Opcode {
   let Types = [NumberTypeClass];
   let HasGroup = 1;

clang/test/AST/Interp/literals.cpp

@@ -269,3 +269,12 @@ namespace band {
   static_assert((1337 & -1) == 1337, "");
   static_assert((0 & gimme(12)) == 0, "");
 };
+
+namespace bitOr {
+  static_assert((10 | 1) == 11, "");
+  static_assert((10 | 10) == 10, "");
+
+  static_assert((1337 | -1) == -1, "");
+  static_assert((0 | gimme(12)) == 12, "");
+  static_assert((12 | true) == 13, "");
+};