diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index f3d5d4c56606cc..9e8f152852fd1e 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -12395,6 +12395,9 @@ def err_hlsl_operator_unsupported : Error<
 
 def err_hlsl_param_qualifier_mismatch :
   Error<"conflicting parameter qualifier %0 on parameter %1">;
+def err_hlsl_vector_compound_assignment_truncation : Error<
+  "left hand operand of type %0 to compound assignment cannot be truncated "
+  "when used with right hand operand of type %1">;
 
 def warn_hlsl_impcast_vector_truncation : Warning<
   "implicit conversion truncates vector: %0 to %1">, InGroup<Conversion>;
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 8b8824c04a3324..aedc4c16d4e9d5 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2979,7 +2979,7 @@ def flax_vector_conversions_EQ : Joined<["-"], "flax-vector-conversions=">, Grou
                     "LangOptions::LaxVectorConversionKind::Integer",
                     "LangOptions::LaxVectorConversionKind::All"]>,
   MarshallingInfoEnum<LangOpts<"LaxVectorConversions">,
-                      open_cl.KeyPath #
+                      !strconcat("(", open_cl.KeyPath, " || ", hlsl.KeyPath, ")") #
                           " ? LangOptions::LaxVectorConversionKind::None" #
                           " : LangOptions::LaxVectorConversionKind::All">;
 def flax_vector_conversions : Flag<["-"], "flax-vector-conversions">, Group<f_Group>,
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index e1c3a99cfa167e..a9ce3681338d46 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -7423,7 +7423,8 @@ class Sema final : public SemaBase {
                                               SourceLocation Loc,
                                               BinaryOperatorKind Opc);
   QualType CheckVectorLogicalOperands(ExprResult &LHS, ExprResult &RHS,
-                                      SourceLocation Loc);
+                                      SourceLocation Loc,
+                                      BinaryOperatorKind Opc);
 
   /// Context in which we're performing a usual arithmetic conversion.
   enum ArithConvKind {
diff --git a/clang/include/clang/Sema/SemaHLSL.h b/clang/include/clang/Sema/SemaHLSL.h
index 311cd58bbcac2c..fa957abc9791af 100644
--- a/clang/include/clang/Sema/SemaHLSL.h
+++ b/clang/include/clang/Sema/SemaHLSL.h
@@ -63,6 +63,11 @@ class SemaHLSL : public SemaBase {
       std::initializer_list<llvm::Triple::EnvironmentType> AllowedStages);
   void DiagnoseAvailabilityViolations(TranslationUnitDecl *TU);
 
+  QualType handleVectorBinOpConversion(ExprResult &LHS, ExprResult &RHS,
+                                       QualType LHSType, QualType RHSType,
+                                       bool IsCompAssign);
+  void emitLogicalOperatorFixIt(Expr *LHS, Expr *RHS, BinaryOperatorKind Opc);
+
   void handleNumThreadsAttr(Decl *D, const ParsedAttr &AL);
   void handleWaveSizeAttr(Decl *D, const ParsedAttr &AL);
   void handleSV_DispatchThreadIDAttr(Decl *D, const ParsedAttr &AL);
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 66df9c969256a2..e072fb65b81328 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -10133,6 +10133,10 @@ QualType Sema::CheckVectorOperands(ExprResult &LHS, ExprResult &RHS,
   const VectorType *RHSVecType = RHSType->getAs<VectorType>();
   assert(LHSVecType || RHSVecType);
 
+  if (getLangOpts().HLSL)
+    return HLSL().handleVectorBinOpConversion(LHS, RHS, LHSType, RHSType,
+                                              IsCompAssign);
+
   // AltiVec-style "vector bool op vector bool" combinations are allowed
   // for some operators but not others.
   if (!AllowBothBool && LHSVecType &&
@@ -12863,7 +12867,8 @@ static void diagnoseXorMisusedAsPow(Sema &S, const ExprResult &XorLHS,
 }
 
 QualType Sema::CheckVectorLogicalOperands(ExprResult &LHS, ExprResult &RHS,
-                                          SourceLocation Loc) {
+                                          SourceLocation Loc,
+                                          BinaryOperatorKind Opc) {
   // Ensure that either both operands are of the same vector type, or
   // one operand is of a vector type and the other is of its element type.
   QualType vType = CheckVectorOperands(LHS, RHS, Loc, false,
@@ -12883,6 +12888,15 @@ QualType Sema::CheckVectorLogicalOperands(ExprResult &LHS, ExprResult &RHS,
   if (!getLangOpts().CPlusPlus &&
       !(isa<ExtVectorType>(vType->getAs<VectorType>())))
     return InvalidLogicalVectorOperands(Loc, LHS, RHS);
+  // Beginning with HLSL 2021, HLSL disallows logical operators on vector
+  // operands and instead requires the use of the `and`, `or`, `any`, `all`, and
+  // `select` functions.
+  if (getLangOpts().HLSL &&
+      getLangOpts().getHLSLVersion() >= LangOptionsBase::HLSL_2021) {
+    (void)InvalidOperands(Loc, LHS, RHS);
+    HLSL().emitLogicalOperatorFixIt(LHS.get(), RHS.get(), Opc);
+    return QualType();
+  }
 
   return GetSignedVectorType(LHS.get()->getType());
 }
@@ -13054,7 +13068,7 @@ inline QualType Sema::CheckLogicalOperands(ExprResult &LHS, ExprResult &RHS,
   // Check vector operands differently.
   if (LHS.get()->getType()->isVectorType() ||
       RHS.get()->getType()->isVectorType())
-    return CheckVectorLogicalOperands(LHS, RHS, Loc);
+    return CheckVectorLogicalOperands(LHS, RHS, Loc, Opc);
 
   bool EnumConstantInBoolContext = false;
   for (const ExprResult &HS : {LHS, RHS}) {
diff --git a/clang/lib/Sema/SemaHLSL.cpp b/clang/lib/Sema/SemaHLSL.cpp
index 1d8ccdda45573f..f17b606a8f262a 100644
--- a/clang/lib/Sema/SemaHLSL.cpp
+++ b/clang/lib/Sema/SemaHLSL.cpp
@@ -401,6 +401,194 @@ void SemaHLSL::DiagnoseAttrStageMismatch(
       << (AllowedStages.size() != 1) << join(StageStrings, ", ");
 }
 
+template <CastKind Kind>
+static void castVector(Sema &S, ExprResult &E, QualType &Ty, unsigned Sz) {
+  if (const auto *VTy = Ty->getAs<VectorType>())
+    Ty = VTy->getElementType();
+  Ty = S.getASTContext().getExtVectorType(Ty, Sz);
+  E = S.ImpCastExprToType(E.get(), Ty, Kind);
+}
+
+template <CastKind Kind>
+static QualType castElement(Sema &S, ExprResult &E, QualType Ty) {
+  E = S.ImpCastExprToType(E.get(), Ty, Kind);
+  return Ty;
+}
+
+static QualType handleFloatVectorBinOpConversion(
+    Sema &SemaRef, ExprResult &LHS, ExprResult &RHS, QualType LHSType,
+    QualType RHSType, QualType LElTy, QualType RElTy, bool IsCompAssign) {
+  bool LHSFloat = LElTy->isRealFloatingType();
+  bool RHSFloat = RElTy->isRealFloatingType();
+
+  if (LHSFloat && RHSFloat) {
+    if (IsCompAssign ||
+        SemaRef.getASTContext().getFloatingTypeOrder(LElTy, RElTy) > 0)
+      return castElement<CK_FloatingCast>(SemaRef, RHS, LHSType);
+
+    return castElement<CK_FloatingCast>(SemaRef, LHS, RHSType);
+  }
+
+  if (LHSFloat)
+    return castElement<CK_IntegralToFloating>(SemaRef, RHS, LHSType);
+
+  assert(RHSFloat);
+  if (IsCompAssign)
+    return castElement<clang::CK_FloatingToIntegral>(SemaRef, RHS, LHSType);
+
+  return castElement<CK_IntegralToFloating>(SemaRef, LHS, RHSType);
+}
+
+static QualType handleIntegerVectorBinOpConversion(
+    Sema &SemaRef, ExprResult &LHS, ExprResult &RHS, QualType LHSType,
+    QualType RHSType, QualType LElTy, QualType RElTy, bool IsCompAssign) {
+
+  int IntOrder = SemaRef.Context.getIntegerTypeOrder(LElTy, RElTy);
+  bool LHSSigned = LElTy->hasSignedIntegerRepresentation();
+  bool RHSSigned = RElTy->hasSignedIntegerRepresentation();
+  auto &Ctx = SemaRef.getASTContext();
+
+  // If both types have the same signedness, use the higher ranked type.
+  if (LHSSigned == RHSSigned) {
+    if (IsCompAssign || IntOrder >= 0)
+      return castElement<CK_IntegralCast>(SemaRef, RHS, LHSType);
+
+    return castElement<CK_IntegralCast>(SemaRef, LHS, RHSType);
+  }
+
+  // If the unsigned type has greater than or equal rank of the signed type, use
+  // the unsigned type.
+  if (IntOrder != (LHSSigned ? 1 : -1)) {
+    if (IsCompAssign || RHSSigned)
+      return castElement<CK_IntegralCast>(SemaRef, RHS, LHSType);
+    return castElement<CK_IntegralCast>(SemaRef, LHS, RHSType);
+  }
+
+  // At this point the signed type has higher rank than the unsigned type, which
+  // means it will be the same size or bigger. If the signed type is bigger, it
+  // can represent all the values of the unsigned type, so select it.
+  if (Ctx.getIntWidth(LElTy) != Ctx.getIntWidth(RElTy)) {
+    if (IsCompAssign || LHSSigned)
+      return castElement<CK_IntegralCast>(SemaRef, RHS, LHSType);
+    return castElement<CK_IntegralCast>(SemaRef, LHS, RHSType);
+  }
+
+  // This is a bit of an odd duck case in HLSL. It shouldn't happen, but can due
+  // to C/C++ leaking through. The place this happens today is long vs long
+  // long. When arguments are vector<unsigned long, N> and vector<long long, N>,
+  // the long long has higher rank than long even though they are the same size.
+
+  // If this is a compound assignment cast the right hand side to the left hand
+  // side's type.
+  if (IsCompAssign)
+    return castElement<CK_IntegralCast>(SemaRef, RHS, LHSType);
+
+  // If this isn't a compound assignment we convert to unsigned long long.
+  QualType ElTy = Ctx.getCorrespondingUnsignedType(LHSSigned ? LElTy : RElTy);
+  QualType NewTy = Ctx.getExtVectorType(
+      ElTy, RHSType->castAs<VectorType>()->getNumElements());
+  (void)castElement<CK_IntegralCast>(SemaRef, RHS, NewTy);
+
+  return castElement<CK_IntegralCast>(SemaRef, LHS, NewTy);
+}
+
+static CastKind getScalarCastKind(ASTContext &Ctx, QualType DestTy,
+                                  QualType SrcTy) {
+  if (DestTy->isRealFloatingType() && SrcTy->isRealFloatingType())
+    return CK_FloatingCast;
+  if (DestTy->isIntegralType(Ctx) && SrcTy->isIntegralType(Ctx))
+    return CK_IntegralCast;
+  if (DestTy->isRealFloatingType())
+    return CK_IntegralToFloating;
+  assert(SrcTy->isRealFloatingType() && DestTy->isIntegralType(Ctx));
+  return CK_FloatingToIntegral;
+}
+
+QualType SemaHLSL::handleVectorBinOpConversion(ExprResult &LHS, ExprResult &RHS,
+                                               QualType LHSType,
+                                               QualType RHSType,
+                                               bool IsCompAssign) {
+  const auto *LVecTy = LHSType->getAs<VectorType>();
+  const auto *RVecTy = RHSType->getAs<VectorType>();
+  auto &Ctx = getASTContext();
+
+  // If the LHS is not a vector and this is a compound assignment, we truncate
+  // the argument to a scalar then convert it to the LHS's type.
+  if (!LVecTy && IsCompAssign) {
+    QualType RElTy = RHSType->castAs<VectorType>()->getElementType();
+    RHS = SemaRef.ImpCastExprToType(RHS.get(), RElTy, CK_HLSLVectorTruncation);
+    RHSType = RHS.get()->getType();
+    if (Ctx.hasSameUnqualifiedType(LHSType, RHSType))
+      return LHSType;
+    RHS = SemaRef.ImpCastExprToType(RHS.get(), LHSType,
+                                    getScalarCastKind(Ctx, LHSType, RHSType));
+    return LHSType;
+  }
+
+  unsigned EndSz = std::numeric_limits<unsigned>::max();
+  unsigned LSz = 0;
+  if (LVecTy)
+    LSz = EndSz = LVecTy->getNumElements();
+  if (RVecTy)
+    EndSz = std::min(RVecTy->getNumElements(), EndSz);
+  assert(EndSz != std::numeric_limits<unsigned>::max() &&
+         "one of the above should have had a value");
+
+  // In a compound assignment, the left operand does not change type, the right
+  // operand is converted to the type of the left operand.
+  if (IsCompAssign && LSz != EndSz) {
+    Diag(LHS.get()->getBeginLoc(),
+         diag::err_hlsl_vector_compound_assignment_truncation)
+        << LHSType << RHSType;
+    return QualType();
+  }
+
+  if (RVecTy && RVecTy->getNumElements() > EndSz)
+    castVector<CK_HLSLVectorTruncation>(SemaRef, RHS, RHSType, EndSz);
+  if (!IsCompAssign && LVecTy && LVecTy->getNumElements() > EndSz)
+    castVector<CK_HLSLVectorTruncation>(SemaRef, LHS, LHSType, EndSz);
+
+  if (!RVecTy)
+    castVector<CK_VectorSplat>(SemaRef, RHS, RHSType, EndSz);
+  if (!IsCompAssign && !LVecTy)
+    castVector<CK_VectorSplat>(SemaRef, LHS, LHSType, EndSz);
+
+  // If we're at the same type after resizing we can stop here.
+  if (Ctx.hasSameUnqualifiedType(LHSType, RHSType))
+    return Ctx.getCommonSugaredType(LHSType, RHSType);
+
+  QualType LElTy = LHSType->castAs<VectorType>()->getElementType();
+  QualType RElTy = RHSType->castAs<VectorType>()->getElementType();
+
+  // Handle conversion for floating point vectors.
+  if (LElTy->isRealFloatingType() || RElTy->isRealFloatingType())
+    return handleFloatVectorBinOpConversion(SemaRef, LHS, RHS, LHSType, RHSType,
+                                            LElTy, RElTy, IsCompAssign);
+
+  assert(LElTy->isIntegralType(Ctx) && RElTy->isIntegralType(Ctx) &&
+         "HLSL Vectors can only contain integer or floating point types");
+  return handleIntegerVectorBinOpConversion(SemaRef, LHS, RHS, LHSType, RHSType,
+                                            LElTy, RElTy, IsCompAssign);
+}
+
+void SemaHLSL::emitLogicalOperatorFixIt(Expr *LHS, Expr *RHS,
+                                        BinaryOperatorKind Opc) {
+  assert((Opc == BO_LOr || Opc == BO_LAnd) &&
+         "Called with non-logical operator");
+  llvm::SmallVector<char, 256> Buff;
+  llvm::raw_svector_ostream OS(Buff);
+  PrintingPolicy PP(SemaRef.getLangOpts());
+  StringRef NewFnName = Opc == BO_LOr ? "or" : "and";
+  OS << NewFnName << "(";
+  LHS->printPretty(OS, nullptr, PP);
+  OS << ", ";
+  RHS->printPretty(OS, nullptr, PP);
+  OS << ")";
+  SourceRange FullRange = SourceRange(LHS->getBeginLoc(), RHS->getEndLoc());
+  SemaRef.Diag(LHS->getBeginLoc(), diag::note_function_suggestion)
+      << NewFnName << FixItHint::CreateReplacement(FullRange, OS.str());
+}
+
 void SemaHLSL::handleNumThreadsAttr(Decl *D, const ParsedAttr &AL) {
   llvm::VersionTuple SMVersion =
       getASTContext().getTargetInfo().getTriple().getOSVersion();
diff --git a/clang/test/SemaHLSL/Language/UsualArithmeticConversions.hlsl b/clang/test/SemaHLSL/Language/UsualArithmeticConversions.hlsl
new file mode 100644
index 00000000000000..d9f20a4cb79ecb
--- /dev/null
+++ b/clang/test/SemaHLSL/Language/UsualArithmeticConversions.hlsl
@@ -0,0 +1,383 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -finclude-default-header -fnative-half-type %s -DERRORS -Wconversion -Wdouble-promotion -verify
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -std=hlsl2018 -finclude-default-header -fnative-half-type %s -DERRORS -Wconversion -Wdouble-promotion -verify
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -finclude-default-header -fnative-half-type %s -ast-dump | FileCheck %s
+
+#if __HLSL_VERSION <= 2021
+// expected-warning@*{{support for HLSL language version hlsl2018 is incomplete, recommend using hlsl202x instead}}
+#endif
+
+//----------------------------------------------------------------------------//
+// Case 1: float4 * int4 and inverse.
+//
+// In both cases here the int is converted to a float and the computation
+// produces a float value.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f4f4i4 'float4 (float4, int4)'
+// CHECK: BinaryOperator {{.*}} 'float4':'vector<float, 4>' '*'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float4':'vector<float, 4>' lvalue ParmVar {{.*}} 'A' 'float4':'vector<float, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'B' 'int4':'vector<int, 4>'
+export float4 f4f4i4(float4 A, int4 B) {
+  return A * B; // expected-warning{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float4' (aka 'vector<float, 4>') may lose precision}}
+}
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f4i4f4 'float4 (float4, int4)'
+// CHECK: BinaryOperator {{.*}} 'float4':'vector<float, 4>' '*'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'B' 'int4':'vector<int, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float4':'vector<float, 4>' lvalue ParmVar {{.*}} 'A' 'float4':'vector<float, 4>'
+export float4 f4i4f4(float4 A, int4 B) {
+  return B * A; // expected-warning{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float4' (aka 'vector<float, 4>') may lose precision}}
+}
+
+//----------------------------------------------------------------------------//
+// Case 2: float4 * int2 and inverse.
+//
+// In both cases the float vector is trunctated to a float2 and the integer
+// vector is converted to a float2.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f2f4i2 'float2 (float4, int2)'
+// CHECK: BinaryOperator {{.*}} 'vector<float, 2>' '*'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<float, 2>' <HLSLVectorTruncation>
+// CHECK-NEXT: ImplicitCastExpr {{.*}}'float4':'vector<float, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float4':'vector<float, 4>' lvalue ParmVar {{.*}} 'A' 'float4':'vector<float, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<float, 2>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int2':'vector<int, 2>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int2':'vector<int, 2>' lvalue ParmVar {{.*}} 'B' 'int2':'vector<int, 2>'
+export float2 f2f4i2(float4 A, int2 B) {
+  // expected-warning@#f2f4i2 {{implicit conversion from 'int2' (aka 'vector<int, 2>') to 'vector<float, 2>' (vector of 2 'float' values) may lose precision}}
+  // expected-warning@#f2f4i2 {{implicit conversion truncates vector: 'float4' (aka 'vector<float, 4>') to 'vector<float, 2>' (vector of 2 'float' values)}}
+  return A * B; // #f2f4i2
+}
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f2i2f4 'float2 (float4, int2)'
+// CHECK: BinaryOperator {{.*}} 'vector<float, 2>' '*'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<float, 2>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int2':'vector<int, 2>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int2':'vector<int, 2>' lvalue ParmVar {{.*}} 'B' 'int2':'vector<int, 2>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<float, 2>' <HLSLVectorTruncation>
+// CHECK-NEXT: ImplicitCastExpr {{.*}}'float4':'vector<float, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float4':'vector<float, 4>' lvalue ParmVar {{.*}} 'A' 'float4':'vector<float, 4>'
+export float2 f2i2f4(float4 A, int2 B) {
+  // expected-warning@#f2i2f4 {{implicit conversion from 'int2' (aka 'vector<int, 2>') to 'vector<float, 2>' (vector of 2 'float' values) may lose precision}}
+  // expected-warning@#f2i2f4 {{implicit conversion truncates vector: 'float4' (aka 'vector<float, 4>') to 'vector<float, 2>' (vector of 2 'float' values)}}
+  return B * A; // #f2i2f4
+}
+
+//----------------------------------------------------------------------------//
+// Case 3: Integers of mismatched sign, equivalent size, but the unsigned type
+// has lower conversion rank.
+//
+// This is the odd-ball case for HLSL that isn't really in spec, but we should
+// handle gracefully. The lower-ranked unsigned type is converted to the
+// equivalent unsigned type of higher rank, and the signed type is also
+// converted to that unsigned type (meaning `unsigned long` becomes `unsinged
+// long long`, and `long long` becomes `unsigned long long`).
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used wierdo 'int4 (vector<unsigned long, 4>, vector<long long, 4>)'
+// CHECK: BinaryOperator {{.*}} 'vector<unsigned long long, 4>' '*'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<unsigned long long, 4>' <IntegralCast>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<unsigned long, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr{{.*}} 'vector<unsigned long, 4>' lvalue ParmVar {{.*}} 'A' 'vector<unsigned long, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<unsigned long long, 4>' <IntegralCast>
+// CHECK-NEXT: ImplicitCastExpr{{.*}}> 'vector<long long, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}}'vector<long long, 4>' lvalue ParmVar {{.*}} 'B' 'vector<long long, 4>'
+export int4 wierdo(vector<unsigned long, 4> A, vector<long long, 4> B) {
+  // expected-warning@#wierdo {{implicit conversion loses integer precision: 'vector<unsigned long long, 4>' (vector of 4 'unsigned long long' values) to 'vector<int, 4>' (vector of 4 'int' values)}}
+  // expected-warning@#wierdo {{implicit conversion changes signedness: 'vector<long long, 4>' (vector of 4 'long long' values) to 'vector<unsigned long long, 4>' (vector of 4 'unsigned long long' values)}}
+  return A * B; // #wierdo
+}
+
+//----------------------------------------------------------------------------//
+// Case 4: Compound assignment of float4 with an int4.
+//
+// In compound assignment the RHS is converted to match the LHS.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f4f4i4compound 'float4 (float4, int4)'
+// CHECK: CompoundAssignOperator {{.*}} 'float4':'vector<float, 4>' lvalue '+=' ComputeLHSTy='float4':'vector<float, 4>' ComputeResultTy='float4':'vector<float, 4>'
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float4':'vector<float, 4>' lvalue ParmVar {{.*}} 'A' 'float4':'vector<float, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'B' 'int4':'vector<int, 4>'
+export float4 f4f4i4compound(float4 A, int4 B) {
+  A += B; // expected-warning{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float4' (aka 'vector<float, 4>') may lose precision}}
+  return A;
+}
+
+
+//----------------------------------------------------------------------------//
+// Case 5: Compound assignment of float2 with an int4.
+//
+// In compound assignment the RHS is converted to match the LHS.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f4f2i4compound 'float4 (float2, int4)'
+// CHECK: CompoundAssignOperator {{.*}} 'float2':'vector<float, 2>' lvalue '+=' ComputeLHSTy='float2':'vector<float, 2>' ComputeResultTy='float2':'vector<float, 2>'
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float2':'vector<float, 2>' lvalue ParmVar {{.*}} 'A' 'float2':'vector<float, 2>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float2':'vector<float, 2>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<int, 2>' <HLSLVectorTruncation>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'B' 'int4':'vector<int, 4>'
+export float4 f4f2i4compound(float2 A, int4 B) {
+  // expected-warning@#f4f2i4compound{{implicit conversion truncates vector: 'int4' (aka 'vector<int, 4>') to 'float2' (aka 'vector<float, 2>')}}
+  // expected-warning@#f4f2i4compound{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float2' (aka 'vector<float, 2>') may lose precision}}
+  A += B; // #f4f2i4compound
+  return A.xyxy;
+}
+
+//----------------------------------------------------------------------------//
+// Case 6: float2 * int4
+//
+// The int4 vector is trunctated to int2 then converted to float2.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f4f2i4 'float2 (float2, int4)'
+// CHECK: BinaryOperator {{.*}} 'float2':'vector<float, 2>' '*'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float2':'vector<float, 2>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float2':'vector<float, 2>' lvalue ParmVar {{.*}} 'A' 'float2':'vector<float, 2>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float2':'vector<float, 2>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<int, 2>' <HLSLVectorTruncation>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'B' 'int4':'vector<int, 4>'
+export float2 f4f2i4(float2 A, int4 B) {
+  // expected-warning@#f4f2i4{{implicit conversion truncates vector: 'int4' (aka 'vector<int, 4>') to 'float2' (aka 'vector<float, 2>')}}
+  // expected-warning@#f4f2i4{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float2' (aka 'vector<float, 2>') may lose precision}}
+  return A * B; // #f4f2i4
+}
+
+//----------------------------------------------------------------------------//
+// Case 7: Compound assignment of half4 with float4, and inverse.
+//
+// In compound assignment the RHS is converted to match the LHS.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f4h4f4compound 'float4 (half4, float4)'
+// CHECK: CompoundAssignOperator {{.*}} 'half4':'vector<half, 4>' lvalue '+=' ComputeLHSTy='half4':'vector<half, 4>' ComputeResultTy='half4':'vector<half, 4>'
+// CHECK-NEXT: DeclRefExpr {{.*}} 'half4':'vector<half, 4>' lvalue ParmVar {{.*}} 'A' 'half4':'vector<half, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'half4':'vector<half, 4>' <FloatingCast>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float4':'vector<float, 4>' lvalue ParmVar {{.*}} 'B' 'float4':'vector<float, 4>'
+export float4 f4h4f4compound(half4 A, float4 B) {
+  A += B; // expected-warning{{implicit conversion loses floating-point precision: 'float4' (aka 'vector<float, 4>') to 'half4' (aka 'vector<half, 4>')}}
+  return B;
+}
+
+// CHECK-LABEL: FunctionDecl {{.*}} used f4f4h4compound 'float4 (float4, half4)'
+// CHECK: CompoundAssignOperator {{.*}} 'float4':'vector<float, 4>' lvalue '+=' ComputeLHSTy='float4':'vector<float, 4>' ComputeResultTy='float4':'vector<float, 4>'
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float4':'vector<float, 4>' lvalue ParmVar {{.*}} 'A' 'float4':'vector<float, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <FloatingCast>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'half4':'vector<half, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'half4':'vector<half, 4>' lvalue ParmVar {{.*}} 'B' 'half4':'vector<half, 4>'
+export float4 f4f4h4compound(float4 A, half4 B) {
+  A += B; // expected-warning{{implicit conversion increases floating-point precision: 'half4' (aka 'vector<half, 4>') to 'float4' (aka 'vector<float, 4>')}}
+  return A;
+}
+
+//----------------------------------------------------------------------------//
+// Case 8: int64_t4 * uint4
+//
+// The unsigned argument is promoted to the higher ranked signed type since it
+// can express all values of the unsgined argument.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used l4l4i4 'int64_t4 (int64_t4, uint4)'
+// CHECK: BinaryOperator {{.*}} 'int64_t4':'vector<int64_t, 4>' '*'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int64_t4':'vector<int64_t, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int64_t4':'vector<int64_t, 4>' lvalue ParmVar {{.*}} 'A' 'int64_t4':'vector<int64_t, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int64_t4':'vector<int64_t, 4>' <IntegralCast>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'uint4':'vector<uint, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'uint4':'vector<uint, 4>' lvalue ParmVar {{.*}} 'B' 'uint4':'vector<uint, 4>'
+export int64_t4 l4l4i4(int64_t4 A, uint4 B) {
+  return A * B;
+}
+
+//----------------------------------------------------------------------------//
+// Case 9: Compound assignment of int4 from int64_t4
+//
+// In compound assignment the RHS is converted to match the LHS.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used i4i4l4compound 'int4 (int4, int64_t4)'
+// CHECK: CompoundAssignOperator {{.*}} 'int4':'vector<int, 4>' lvalue '+=' ComputeLHSTy='int4':'vector<int, 4>' ComputeResultTy='int4':'vector<int, 4>'
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'A' 'int4':'vector<int, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <IntegralCast>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int64_t4':'vector<int64_t, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int64_t4':'vector<int64_t, 4>' lvalue ParmVar {{.*}} 'B' 'int64_t4':'vector<int64_t, 4>'
+export int4 i4i4l4compound(int4 A, int64_t4 B) {
+  A += B; // expected-warning{{implicit conversion loses integer precision: 'int64_t4' (aka 'vector<int64_t, 4>') to 'int4' (aka 'vector<int, 4>')}}
+  return A;
+}
+
+//----------------------------------------------------------------------------//
+// Case 10: Compound assignment of vector<unsigned long, 4> with argument of
+// vector<long long, 4>
+//
+// In compound assignment the RHS is converted to match the LHS. This one is
+// also the weird case because it is out of spec, but we should handle it
+// gracefully.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used wierdocompound 'vector<unsigned long, 4> (vector<unsigned long, 4>, vector<long long, 4>)'
+// CHECK: CompoundAssignOperator {{.*}} 'vector<unsigned long, 4>' lvalue '+=' ComputeLHSTy='vector<unsigned long, 4>' ComputeResultTy='vector<unsigned long, 4>'
+// CHECK-NEXT: DeclRefExpr {{.*}} 'vector<unsigned long, 4>' lvalue ParmVar {{.*}} 'A' 'vector<unsigned long, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<unsigned long, 4>' <IntegralCast>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<long long, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'vector<long long, 4>' lvalue ParmVar {{.*}} 'B' 'vector<long long, 4>'
+export vector<unsigned long, 4> wierdocompound(vector<unsigned long, 4> A, vector<long long, 4> B) {
+  // expected-warning@#wierdocompound{{implicit conversion changes signedness: 'vector<long long, 4>' (vector of 4 'long long' values) to 'vector<unsigned long, 4>' (vector of 4 'unsigned long' values)}}
+  A += B; // #wierdocompound
+  return A;
+}
+
+//----------------------------------------------------------------------------//
+// Case 11: Compound assignment of scalar with vector argument.
+//
+// Because the LHS of a compound assignment cannot change type, the RHS must be
+// implicitly convertable to the LHS type.
+//----------------------------------------------------------------------------//
+
+// CHECK-LABEL: FunctionDecl {{.*}} used ffi2compound 'float (float, int2)'
+// CHECK: CompoundAssignOperator {{.*}} 'float' lvalue '+=' ComputeLHSTy='float' ComputeResultTy='float'
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float' lvalue ParmVar {{.*}} 'A' 'float'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int' <HLSLVectorTruncation>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int2':'vector<int, 2>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int2':'vector<int, 2>' lvalue ParmVar {{.*}} 'B' 'int2':'vector<int, 2>'
+export float ffi2compound(float A, int2 B) {
+  A += B; // expected-warning {{implicit conversion turns vector to scalar: 'int2' (aka 'vector<int, 2>') to 'float'}}
+  return A;
+}
+
+// CHECK-LABEL: FunctionDecl {{.*}} used iif2compound 'int (int, float2)'
+// CHECK: CompoundAssignOperator {{.*}} 'int' lvalue '+=' ComputeLHSTy='int' ComputeResultTy='int'
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int' lvalue ParmVar {{.*}} 'A' 'int'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int' <FloatingToIntegral>
+// CHECK-NEXT: mplicitCastExpr {{.*}} 'float' <HLSLVectorTruncation>
+// CHECK-NEXT: ImplicitCastExpr{{.*}} 'float2':'vector<float, 2>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float2':'vector<float, 2>' lvalue ParmVar {{.*}} 'B' 'float2':'vector<float, 2>'
+export int iif2compound(int A, float2 B) {
+  A += B; // expected-warning{{implicit conversion turns vector to scalar: 'float2' (aka 'vector<float, 2>') to 'int'}}
+  return A;
+}
+
+
+//----------------------------------------------------------------------------//
+// Case 12: Compound assignment of vector of larger size than the argument.
+//
+// Because the LHS of a compound assignment cannot change type, the RHS must be
+// implicitly convertable to the LHS type. This fails since the RHS type can't
+// be vector-extended implicitly.
+//----------------------------------------------------------------------------//
+
+#ifdef ERRORS
+// The only cases that are really illegal here are when the RHS is a vector that
+// is larger than the LHS or when the LHS is a scalar.
+
+export float2 f2f4i2compound(float4 A, int2 B) {
+  A += B; // expected-error{{left hand operand of type 'float4' (aka 'vector<float, 4>') to compound assignment cannot be truncated when used with right hand operand of type 'int2' (aka 'vector<int, 2>')}}
+  return A.xy;
+}
+
+#endif
+
+//----------------------------------------------------------------------------//
+// Case 13: Comparison operators for mismatched arguments follow the same rules.
+//
+// Compare operators convert each argument following the usual arithmetic
+// conversions.
+//----------------------------------------------------------------------------//
+
+// Note: these cases work and generate correct code, but the way they get there
+// may change with https://github.com/llvm/llvm-project/issues/91639, because
+// representing boolean vectors as 32-bit integer vectors will allow more
+// efficient code generation.
+
+// CHECK-LABEL: FunctionDecl {{.*}} used b4f4i4Compare 'bool4 (float4, int4)'
+// CHECK: ImplicitCastExpr {{.*}} 'vector<bool, 4>' <IntegralToBoolean>
+// CHECK-NEXT: BinaryOperator {{.*}} 'vector<int, 4>' '<'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float4':'vector<float, 4>' lvalue ParmVar {{.*}} 'A' 'float4':'vector<float, 4>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float4':'vector<float, 4>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'B' 'int4':'vector<int, 4>'
+export bool4 b4f4i4Compare(float4 A, int4 B) {
+  return A < B; // expected-warning{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float4' (aka 'vector<float, 4>') may lose precision}}
+}
+
+
+// CHECK-LABEL: FunctionDecl {{.*}} used b2f2i4Compare 'bool2 (float2, int4)'
+// CHECK: ImplicitCastExpr {{.*}} 'vector<bool, 2>' <IntegralToBoolean>
+// CHECK-NEXT: BinaryOperator {{.*}} 'vector<int, 2>' '<='
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float2':'vector<float, 2>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float2':'vector<float, 2>' lvalue ParmVar {{.*}} 'A' 'float2':'vector<float, 2>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float2':'vector<float, 2>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<int, 2>' <HLSLVectorTruncation>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'B' 'int4':'vector<int, 4>'
+
+export bool2 b2f2i4Compare(float2 A, int4 B) {
+  // expected-warning@#b2f2i4Compare{{implicit conversion truncates vector: 'int4' (aka 'vector<int, 4>') to 'float2' (aka 'vector<float, 2>')}}
+  // expected-warning@#b2f2i4Compare{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float2' (aka 'vector<float, 2>') may lose precision}}
+  return A <= B; // #b2f2i4Compare
+}
+
+// CHECK-LABEL: FunctionDecl {{.*}} used b4fi4Compare 'bool4 (float, int4)'
+// CHECK: ImplicitCastExpr {{.*}} 'vector<bool, 4>' <IntegralToBoolean>
+// CHECK-NEXT: BinaryOperator {{.*}} 'vector<int, 4>' '>'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<float, 4>' <VectorSplat>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'float' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'float' lvalue ParmVar {{.*}} 'A' 'float'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'vector<float, 4>' <IntegralToFloating>
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'int4':'vector<int, 4>' <LValueToRValue>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'int4':'vector<int, 4>' lvalue ParmVar {{.*}} 'B' 'int4':'vector<int, 4>'
+export bool4 b4fi4Compare(float A, int4 B) {
+  return A > B; // expected-warning{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'vector<float, 4>' (vector of 4 'float' values) may lose precision}}
+}
+
+//----------------------------------------------------------------------------//
+// Case 14: Logical operators on vectors are disallowed in HLSL 2021+
+//----------------------------------------------------------------------------//
+
+#ifdef ERRORS
+
+#if __HLSL_VERSION >= 2021
+// expected-error@#b4f4i4Logical{{invalid operands to binary expression ('float4' (aka 'vector<float, 4>') and 'int4' (aka 'vector<int, 4>'))}}
+// expected-note@#b4f4i4Logical{{did you mean or?}}
+#else
+// expected-warning@#b4f4i4Logical{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float4' (aka 'vector<float, 4>') may lose precision}}
+#endif
+
+export bool4 b4f4i4Logical(float4 A, int4 B) {
+  return A || B; // #b4f4i4Logical
+}
+
+#if __HLSL_VERSION >= 2021
+// expected-error@#b2f2i4Logical{{invalid operands to binary expression ('float2' (aka 'vector<float, 2>') and 'int4' (aka 'vector<int, 4>'))}}
+// expected-note@#b2f2i4Logical{{did you mean and?}}
+#else
+// expected-warning@#b2f2i4Logical{{implicit conversion truncates vector: 'int4' (aka 'vector<int, 4>') to 'float2' (aka 'vector<float, 2>')}}
+// expected-warning@#b2f2i4Logical{{implicit conversion from 'int4' (aka 'vector<int, 4>') to 'float2' (aka 'vector<float, 2>') may lose precision}}
+#endif
+
+export bool2 b2f2i4Logical(float2 A, int4 B) {
+  return A && B; // #b2f2i4Logical
+}
+
+#if __HLSL_VERSION >= 2021
+// expected-error@#b2b2b2Logical{{invalid operands to binary expression ('bool2' (aka 'vector<bool, 2>') and 'bool2')}}
+// expected-note@#b2b2b2Logical{{did you mean and?}}
+#endif
+
+export bool2 b2b2b2Logical(bool2 A, bool2 B) {
+  return A && B; // #b2b2b2Logical
+}
+
+#endif