[clang][bytecode] Implement constexpr vector unary operators +, -, ~, !

clang/lib/AST/ByteCode/Compiler.cpp

@@ -4991,6 +4991,8 @@ bool Compiler<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
   const Expr *SubExpr = E->getSubExpr();
   if (SubExpr->getType()->isAnyComplexType())
     return this->VisitComplexUnaryOperator(E);
+  if (SubExpr->getType()->isVectorType())
+    return this->VisitVectorUnaryOperator(E);
   std::optional<PrimType> T = classify(SubExpr->getType());
 
   switch (E->getOpcode()) {
@@ -5312,6 +5314,110 @@ bool Compiler<Emitter>::VisitComplexUnaryOperator(const UnaryOperator *E) {
   return true;
 }
 
+template <class Emitter>
+bool Compiler<Emitter>::VisitVectorUnaryOperator(const UnaryOperator *E) {
+  const Expr *SubExpr = E->getSubExpr();
+  assert(SubExpr->getType()->isVectorType());
+
+  if (DiscardResult)
+    return this->discard(SubExpr);
+
+  auto UnaryOp = E->getOpcode();
+  if (UnaryOp != UO_Plus && UnaryOp != UO_Minus && UnaryOp != UO_LNot &&
+      UnaryOp != UO_Not)
+    return this->emitInvalid(E);
+
+  // Nothing to do here.
+  if (UnaryOp == UO_Plus)
+    return this->delegate(SubExpr);
+
+  if (!Initializing) {
+    std::optional<unsigned> LocalIndex = allocateLocal(SubExpr);
+    if (!LocalIndex)
+      return false;
+    if (!this->emitGetPtrLocal(*LocalIndex, E))
+      return false;
+  }
+
+  // The offset of the temporary, if we created one.
+  unsigned SubExprOffset =
+      this->allocateLocalPrimitive(SubExpr, PT_Ptr, true, false);
+  if (!this->visit(SubExpr))
+    return false;
+  if (!this->emitSetLocal(PT_Ptr, SubExprOffset, E))
+    return false;
+
+  const auto *VecTy = SubExpr->getType()->getAs<VectorType>();
+  PrimType ElemT = classifyVectorElementType(SubExpr->getType());
+  auto getElem = [=](unsigned Offset, unsigned Index) -> bool {
+    if (!this->emitGetLocal(PT_Ptr, Offset, E))
+      return false;
+    return this->emitArrayElemPop(ElemT, Index, E);
+  };
+
+  switch (UnaryOp) {
+  case UO_Minus:
+    for (unsigned I = 0; I != VecTy->getNumElements(); ++I) {
+      if (!getElem(SubExprOffset, I))
+        return false;
+      if (!this->emitNeg(ElemT, E))
+        return false;
+      if (!this->emitInitElem(ElemT, I, E))
+        return false;
+    }
+    break;
+  case UO_LNot: { // !x
+    // In C++, the logic operators !, &&, || are available for vectors. !v is
+    // equivalent to v == 0.
+    //
+    // The result of the comparison is a vector of the same width and number of
+    // elements as the comparison operands with a signed integral element type.
+    //
+    // https://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html
+    QualType ResultVecTy = E->getType();
+    PrimType ResultVecElemT =
+        classifyPrim(ResultVecTy->getAs<VectorType>()->getElementType());
+    for (unsigned I = 0; I != VecTy->getNumElements(); ++I) {
+      if (!getElem(SubExprOffset, I))
+        return false;
+      // operator ! on vectors returns -1 for 'truth', so negate it.
+      if (!this->emitPrimCast(ElemT, PT_Bool, Ctx.getASTContext().BoolTy, E))
+        return false;
+      if (!this->emitInv(E))
+        return false;
+      if (!this->emitPrimCast(PT_Bool, ElemT, VecTy->getElementType(), E))
+        return false;
+      if (!this->emitNeg(ElemT, E))
+        return false;
+      if (ElemT != ResultVecElemT &&
+          !this->emitPrimCast(ElemT, ResultVecElemT, ResultVecTy, E))
+        return false;
+      if (!this->emitInitElem(ResultVecElemT, I, E))
+        return false;
+    }
+    break;
+  }
+  case UO_Not: // ~x
+    for (unsigned I = 0; I != VecTy->getNumElements(); ++I) {
+      if (!getElem(SubExprOffset, I))
+        return false;
+      if (ElemT == PT_Bool) {
+        if (!this->emitInv(E))
+          return false;
+      } else {
+        if (!this->emitComp(ElemT, E))
+          return false;
+      }
+      if (!this->emitInitElem(ElemT, I, E))
+        return false;
+    }
+    break;
+  default:
+    llvm_unreachable("Unsupported unary operators should be handled up front");
+  }
+  return true;
+}
+
 template <class Emitter>
 bool Compiler<Emitter>::visitDeclRef(const ValueDecl *D, const Expr *E) {
   if (DiscardResult)

clang/lib/AST/ByteCode/Compiler.h

@@ -139,6 +139,7 @@ class Compiler : public ConstStmtVisitor<Compiler<Emitter>, bool>,
   bool VisitGNUNullExpr(const GNUNullExpr *E);
   bool VisitCXXThisExpr(const CXXThisExpr *E);
   bool VisitUnaryOperator(const UnaryOperator *E);
+  bool VisitVectorUnaryOperator(const UnaryOperator *E);
   bool VisitComplexUnaryOperator(const UnaryOperator *E);
   bool VisitDeclRefExpr(const DeclRefExpr *E);
   bool VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E);
@@ -349,6 +350,11 @@ class Compiler : public ConstStmtVisitor<Compiler<Emitter>, bool>,
     return *this->classify(ElemType);
   }
 
+  PrimType classifyVectorElementType(QualType T) const {
+    assert(T->isVectorType());
+    return *this->classify(T->getAs<VectorType>()->getElementType());
+  }
+
   bool emitComplexReal(const Expr *SubExpr);
   bool emitComplexBoolCast(const Expr *E);
   bool emitComplexComparison(const Expr *LHS, const Expr *RHS,

clang/test/AST/ByteCode/constexpr-vectors.cpp

@@ -0,0 +1,90 @@
+// RUN: %clang_cc1 %s -triple x86_64-linux-gnu -std=c++14 -fsyntax-only -verify
+// RUN: %clang_cc1 %s -triple x86_64-linux-gnu -fexperimental-new-constant-interpreter -std=c++14 -fsyntax-only -verify
+
+using FourCharsVecSize __attribute__((vector_size(4))) = char;
+using FourIntsVecSize __attribute__((vector_size(16))) = int;
+using FourLongLongsVecSize __attribute__((vector_size(32))) = long long;
+using FourFloatsVecSize __attribute__((vector_size(16))) = float;
+using FourDoublesVecSize __attribute__((vector_size(32))) = double;
+using FourI128VecSize __attribute__((vector_size(64))) = __int128;
+
+using FourCharsExtVec __attribute__((ext_vector_type(4))) = char;
+using FourIntsExtVec __attribute__((ext_vector_type(4))) = int;
+using FourI128ExtVec __attribute__((ext_vector_type(4))) = __int128;
+
+// Only int vs float makes a difference here, so we only need to test 1 of each.
+// Test Char to make sure the mixed-nature of shifts around char is evident.
+void CharUsage() {
+  constexpr auto H = FourCharsVecSize{-1, -1, 0, -1};
+  constexpr auto InvH = -H;
+  static_assert(InvH[0] == 1 && InvH[1] == 1 && InvH[2] == 0 && InvH[3] == 1, "");
+
+  constexpr auto ae = ~FourCharsVecSize{1, 2, 10, 20};
+  static_assert(ae[0] == -2 && ae[1] == -3 && ae[2] == -11 && ae[3] == -21, "");
+
+  constexpr auto af = !FourCharsVecSize{0, 1, 8, -1};
+  static_assert(af[0] == -1 && af[1] == 0 && af[2] == 0 && af[3] == 0, "");
+}
+
+void CharExtVecUsage() {
+  constexpr auto H = FourCharsExtVec{-1, -1, 0, -1};
+  constexpr auto InvH = -H;
+  static_assert(InvH[0] == 1 && InvH[1] == 1 && InvH[2] == 0 && InvH[3] == 1, "");
+
+  constexpr auto ae = ~FourCharsExtVec{1, 2, 10, 20};
+  static_assert(ae[0] == -2 && ae[1] == -3 && ae[2] == -11 && ae[3] == -21, "");
+
+  constexpr auto af = !FourCharsExtVec{0, 1, 8, -1};
+  static_assert(af[0] == -1 && af[1] == 0 && af[2] == 0 && af[3] == 0, "");
+}
+
+void FloatUsage() {
+  constexpr auto Y = FourFloatsVecSize{1.200000e+01, 1.700000e+01, -1.000000e+00, -1.000000e+00};
+  constexpr auto Z = -Y;
+  static_assert(Z[0] == -1.200000e+01 && Z[1] == -1.700000e+01 && Z[2] == 1.000000e+00 && Z[3] == 1.000000e+00, "");
+
+  // Operator ~ is illegal on floats.
+  constexpr auto ae = ~FourFloatsVecSize{0, 1, 8, -1}; // expected-error {{invalid argument type}}
+
+  constexpr auto af = !FourFloatsVecSize{0, 1, 8, -1};
+  static_assert(af[0] == -1 && af[1] == 0 && af[2] == 0 && af[3] == 0, "");
+}
+
+void FloatVecUsage() {
+  constexpr auto Y = FourFloatsVecSize{1.200000e+01, 1.700000e+01, -1.000000e+00, -1.000000e+00};
+  constexpr auto Z = -Y;
+  static_assert(Z[0] == -1.200000e+01 && Z[1] == -1.700000e+01 && Z[2] == 1.000000e+00 && Z[3] == 1.000000e+00, "");
+
+  // Operator ~ is illegal on floats.
+  constexpr auto ae = ~FourFloatsVecSize{0, 1, 8, -1}; // expected-error {{invalid argument type}}
+
+  constexpr auto af = !FourFloatsVecSize{0, 1, 8, -1};
+  static_assert(af[0] == -1 && af[1] == 0 && af[2] == 0 && af[3] == 0, "");
+}
+
+void I128Usage() {
+  // Operator ~ is illegal on floats, so no test for that.
+  constexpr auto c = ~FourI128VecSize{1, 2, 10, 20};
+   static_assert(c[0] == -2 && c[1] == -3 && c[2] == -11 && c[3] == -21, "");
+
+  constexpr auto d = !FourI128VecSize{0, 1, 8, -1};
+  static_assert(d[0] == -1 && d[1] == 0 && d[2] == 0 && d[3] == 0, "");
+}
+
+void I128VecUsage() {
+  // Operator ~ is illegal on floats, so no test for that.
+  constexpr auto c = ~FourI128ExtVec{1, 2, 10, 20};
+  static_assert(c[0] == -2 && c[1] == -3 && c[2] == -11 && c[3] == -21, "");
+
+  constexpr auto d = !FourI128ExtVec{0, 1, 8, -1};
+  static_assert(d[0] == -1 && d[1] == 0 && d[2] == 0 && d[3] == 0, "");
+}
+
+using FourBoolsExtVec __attribute__((ext_vector_type(4))) = bool;
+void BoolVecUsage() {
+  constexpr auto j = !FourBoolsExtVec{true, false, true, false};
+  static_assert(j[0] == false && j[1] == true && j[2] == false && j[3] == true, "");
+
+  constexpr auto k = ~FourBoolsExtVec{true, false, true, false};
+  static_assert(k[0] == false && k[1] == true && k[2] == false && k[3] == true, "");
+}