[HLSL] get inout/out ABI for array parameters working

clang/include/clang/AST/Type.h

@@ -3754,6 +3754,8 @@ class ArrayParameterType : public ConstantArrayType {
   static bool classof(const Type *T) {
     return T->getTypeClass() == ArrayParameter;
   }
+
+  QualType getConstantArrayType(const ASTContext &Ctx) const;
 };
 
 /// Represents a C array with an unspecified size.  For example 'int A[]' has

clang/lib/AST/Type.cpp

@@ -267,6 +267,12 @@ void ConstantArrayType::Profile(llvm::FoldingSetNodeID &ID,
     SizeExpr->Profile(ID, Context, true);
 }
 
+QualType ArrayParameterType::getConstantArrayType(const ASTContext &Ctx) const {
+  return Ctx.getConstantArrayType(getElementType(), getSize(), getSizeExpr(),
+                                  getSizeModifier(),
+                                  getIndexTypeQualifiers().getAsOpaqueValue());
+}
+
 DependentSizedArrayType::DependentSizedArrayType(QualType et, QualType can,
                                                  Expr *e, ArraySizeModifier sm,
                                                  unsigned tq,

clang/lib/CodeGen/CGCall.cpp

@@ -4725,15 +4725,17 @@ void CodeGenFunction::EmitCallArg(CallArgList &args, const Expr *E,
     return emitWritebackArg(*this, args, CRE);
   }
 
-  assert(type->isReferenceType() == E->isGLValue() &&
-         "reference binding to unmaterialized r-value!");
-
   // Add writeback for HLSLOutParamExpr.
+  // Needs to be before the assert below because HLSLOutArgExpr is an LValue
+  // and is not a reference.
   if (const HLSLOutArgExpr *OE = dyn_cast<HLSLOutArgExpr>(E)) {
     EmitHLSLOutArgExpr(OE, args, type);
     return;
   }
 
+  assert(type->isReferenceType() == E->isGLValue() &&
+         "reference binding to unmaterialized r-value!");
+
   if (E->isGLValue()) {
     assert(E->getObjectKind() == OK_Ordinary);
     return args.add(EmitReferenceBindingToExpr(E), type);
@@ -5322,6 +5324,14 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
           IRCallArgs[FirstIRArg] = Val;
           break;
         }
+      } else if (I->getType()->isArrayParameterType()) {
+        // Don't produce a temporary for ArrayParameterType arguments.
+        // ArrayParameterType arguments are only created from
+        // HLSL_ArrayRValue casts and HLSLOutArgExpr expressions, both
+        // of which create temporaries already. This allows us to just use the
+        // scalar for the decayed array pointer as the argument directly.
+        IRCallArgs[FirstIRArg] = I->getKnownRValue().getScalarVal();
+        break;
       }
 
       // For non-aggregate args and aggregate args meeting conditions above

clang/lib/CodeGen/CGExpr.cpp

@@ -5827,9 +5827,12 @@ LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
 // This function implements trivial copy assignment for HLSL's
 // assignable constant arrays.
 LValue CodeGenFunction::EmitHLSLArrayAssignLValue(const BinaryOperator *E) {
-  LValue TrivialAssignmentRHS = EmitLValue(E->getRHS());
+  // Don't emit an LValue for the RHS because it might not be an LValue
   LValue LHS = EmitLValue(E->getLHS());
-  EmitAggregateAssign(LHS, TrivialAssignmentRHS, E->getLHS()->getType());
+  // In C the RHS of an assignment operator is an RValue.
+  // EmitAggregateAssign takes anan LValue for the RHS. Instead we can call
+  // EmitInitializationToLValue to emit an RValue into an LValue.
+  EmitInitializationToLValue(E->getRHS(), LHS);
   return LHS;
 }
 

clang/lib/Sema/Sema.cpp

@@ -723,6 +723,15 @@ ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
   QualType ExprTy = Context.getCanonicalType(E->getType());
   QualType TypeTy = Context.getCanonicalType(Ty);
 
+  // This cast is used in place of a regular LValue to RValue cast for
+  // HLSL Array Parameter Types. It needs to be emitted even if
+  // ExprTy == TypeTy, except if E is an HLSLOutArgExpr
+  // Emitting a cast in that case will prevent HLSLOutArgExpr from
+  // being handled properly in EmitCallArg
+  if (Kind == CK_HLSLArrayRValue && !isa<HLSLOutArgExpr>(E))
+    return ImplicitCastExpr::Create(Context, Ty, Kind, E, BasePath, VK,
+                                    CurFPFeatureOverrides());
+
   if (ExprTy == TypeTy)
     return E;
 

clang/lib/Sema/SemaExprCXX.cpp

@@ -4431,10 +4431,21 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
     break;
 
   case ICK_HLSL_Array_RValue:
-    FromType = Context.getArrayParameterType(FromType);
-    From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
-                             /*BasePath=*/nullptr, CCK)
-               .get();
+    if (ToType->isArrayParameterType()) {
+      FromType = Context.getArrayParameterType(FromType);
+      From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
+                               /*BasePath=*/nullptr, CCK)
+                 .get();
+    } else { // FromType must be ArrayParameterType
+      assert(FromType->isArrayParameterType() &&
+             "FromType must be ArrayParameterType in ICK_HLSL_Array_RValue \
+              if it is not ToType");
+      const ArrayParameterType *APT = cast<ArrayParameterType>(FromType);
+      FromType = APT->getConstantArrayType(Context);
+      From = ImpCastExprToType(From, FromType, CK_HLSLArrayRValue, VK_PRValue,
+                               /*BasePath=*/nullptr, CCK)
+                 .get();
+    }
     break;
 
   case ICK_Function_To_Pointer:

clang/lib/Sema/SemaOverload.cpp

@@ -2236,33 +2236,24 @@ static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
       return false;
     }
   }
-  // Lvalue-to-rvalue conversion (C++11 4.1):
-  //   A glvalue (3.10) of a non-function, non-array type T can
-  //   be converted to a prvalue.
-  bool argIsLValue = From->isGLValue();
-  if (argIsLValue && !FromType->canDecayToPointerType() &&
-      S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
-    SCS.First = ICK_Lvalue_To_Rvalue;
-
-    // C11 6.3.2.1p2:
-    //   ... if the lvalue has atomic type, the value has the non-atomic version
-    //   of the type of the lvalue ...
-    if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
-      FromType = Atomic->getValueType();
 
-    // If T is a non-class type, the type of the rvalue is the
-    // cv-unqualified version of T. Otherwise, the type of the rvalue
-    // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
-    // just strip the qualifiers because they don't matter.
-    FromType = FromType.getUnqualifiedType();
-  } else if (S.getLangOpts().HLSL && FromType->isConstantArrayType() &&
-             ToType->isConstantArrayType()) {
+  bool argIsLValue = From->isGLValue();
+  // To handle conversion from ArrayParameterType to ConstantArrayType
+  // this block must be above the one below because Array parameters
+  // do not decay and when handling HLSLOutArgExprs and
+  // the From expression is an LValue.
+  if (S.getLangOpts().HLSL && FromType->isConstantArrayType() &&
+      ToType->isConstantArrayType()) {
     // HLSL constant array parameters do not decay, so if the argument is a
     // constant array and the parameter is an ArrayParameterType we have special
     // handling here.
     if (ToType->isArrayParameterType()) {
       FromType = S.Context.getArrayParameterType(FromType);
       SCS.First = ICK_HLSL_Array_RValue;
+    } else if (FromType->isArrayParameterType()) {
+      const ArrayParameterType *APT = cast<ArrayParameterType>(FromType);
+      FromType = APT->getConstantArrayType(S.Context);
+      SCS.First = ICK_HLSL_Array_RValue;
     } else {
       SCS.First = ICK_Identity;
     }
@@ -2273,6 +2264,25 @@ static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
 
     SCS.setAllToTypes(ToType);
     return true;
+  } else if (argIsLValue && !FromType->canDecayToPointerType() &&
+             S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
+    // Lvalue-to-rvalue conversion (C++11 4.1):
+    //   A glvalue (3.10) of a non-function, non-array type T can
+    //   be converted to a prvalue.
+
+    SCS.First = ICK_Lvalue_To_Rvalue;
+
+    // C11 6.3.2.1p2:
+    //   ... if the lvalue has atomic type, the value has the non-atomic version
+    //   of the type of the lvalue ...
+    if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
+      FromType = Atomic->getValueType();
+
+    // If T is a non-class type, the type of the rvalue is the
+    // cv-unqualified version of T. Otherwise, the type of the rvalue
+    // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
+    // just strip the qualifiers because they don't matter.
+    FromType = FromType.getUnqualifiedType();
   } else if (FromType->isArrayType()) {
     // Array-to-pointer conversion (C++ 4.2)
     SCS.First = ICK_Array_To_Pointer;

clang/lib/Sema/SemaType.cpp

@@ -5681,6 +5681,9 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
   assert(!T.isNull() && "T must not be null at the end of this function");
   if (!AreDeclaratorChunksValid)
     return Context.getTrivialTypeSourceInfo(T);
+
+  if (state.didParseHLSLParamMod() && !T->isConstantArrayType())
+    T = S.HLSL().getInoutParameterType(T);
   return GetTypeSourceInfoForDeclarator(state, T, TInfo);
 }
 
@@ -8634,7 +8637,6 @@ static void HandleHLSLParamModifierAttr(TypeProcessingState &State,
     return;
   if (Attr.getSemanticSpelling() == HLSLParamModifierAttr::Keyword_inout ||
       Attr.getSemanticSpelling() == HLSLParamModifierAttr::Keyword_out) {
-    CurType = S.HLSL().getInoutParameterType(CurType);
     State.setParsedHLSLParamMod(true);
   }
 }

clang/test/AST/HLSL/ArrayOutArgExpr.hlsl

@@ -0,0 +1,63 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library -x hlsl -ast-dump %s | FileCheck %s
+
+// CHECK-LABEL: increment
+void increment(inout int Arr[2]) {
+  for (int I = 0; I < 2; I++)
+    Arr[0] += 2;
+}
+
+// CHECK-LABEL: call
+// CHECK: CallExpr 0x{{.*}} {{.*}} 'void'
+// CHECK: ImplicitCastExpr 0x{{.*}} {{.*}} 'void (*)(inout int[2])' <FunctionToPointerDecay>
+// CHECK: DeclRefExpr 0x{{.*}} {{.*}} 'void (inout int[2])' lvalue Function 0x{{.*}} 'increment' 'void (inout int[2])'
+// CHECK: HLSLOutArgExpr 0x{{.*}} {{.*}} 'int[2]' lvalue inout
+// CHECK: OpaqueValueExpr [[A:0x.*]] {{.*}} 'int[2]' lvalue
+// CHECK: DeclRefExpr [[B:0x.*]] {{.*}} 'int[2]' lvalue Var [[E:0x.*]] 'A' 'int[2]'
+// CHECK: OpaqueValueExpr [[C:0x.*]] {{.*}} 'int[2]' lvalue
+// CHECK: ImplicitCastExpr [[D:0x.*]] {{.*}} 'int[2]' <HLSLArrayRValue>
+// CHECK: OpaqueValueExpr [[A]] {{.*}} 'int[2]' lvalue
+// CHECK: DeclRefExpr [[B]] {{.*}} 'int[2]' lvalue Var [[E]] 'A' 'int[2]'
+// CHECK: BinaryOperator 0x{{.*}} {{.*}} 'int[2]' lvalue '='
+// CHECK: OpaqueValueExpr [[A]] {{.*}} 'int[2]' lvalue
+// CHECK: DeclRefExpr 0x{{.*}} {{.*}} 'int[2]' lvalue Var [[E]] 'A' 'int[2]'
+// CHECK: ImplicitCastExpr 0x{{.*}} {{.*}} 'int[2]' <HLSLArrayRValue>
+// CHECK: OpaqueValueExpr [[C]] {{.*}} 'int[2]' lvalue
+// CHECK: ImplicitCastExpr [[D]] {{.*}} 'int[2]' <HLSLArrayRValue>
+// CHECK: OpaqueValueExpr [[A]] {{.*}} 'int[2]' lvalue
+// CHECK: DeclRefExpr [[B]] {{.*}} 'int[2]' lvalue Var [[E]] 'A' 'int[2]'
+export int call() {
+  int A[2] = { 0, 1 };
+  increment(A);
+  return A[0];
+}
+
+// CHECK-LABEL: fn2
+void fn2(out int Arr[2]) {
+  Arr[0] += 5;
+  Arr[1] += 6;
+}
+
+// CHECK-LABEL: call2
+// CHECK: CallExpr 0x{{.*}} {{.*}} 'void'
+// CHECK: ImplicitCastExpr 0x{{.*}} {{.*}} 'void (*)(out int[2])' <FunctionToPointerDecay>
+// CHECK: DeclRefExpr 0x{{.*}} {{.*}} 'void (out int[2])' lvalue Function 0x{{.*}} 'fn2' 'void (out int[2])'
+// CHECK: HLSLOutArgExpr 0x{{.*}} {{.*}} 'int[2]' lvalue out
+// CHECK: OpaqueValueExpr [[A:0x.*]] {{.*}} 'int[2]' lvalue
+// CHECK: DeclRefExpr [[B:0x.*]] {{.*}} 'int[2]' lvalue Var [[E:0x.*]] 'A' 'int[2]'
+// CHECK: OpaqueValueExpr [[C:0x.*]] {{.*}} 'int[2]' lvalue
+// CHECK: ImplicitCastExpr [[D:0x.*]] {{.*}} 'int[2]' <HLSLArrayRValue>
+// CHECK: OpaqueValueExpr [[A]] {{.*}} 'int[2]' lvalue
+// CHECK: DeclRefExpr [[B]] {{.*}} 'int[2]' lvalue Var [[E]] 'A' 'int[2]'
+// CHECK: BinaryOperator 0x{{.*}} {{.*}} 'int[2]' lvalue '='
+// CHECK: OpaqueValueExpr [[A]] {{.*}} 'int[2]' lvalue
+// CHECK: DeclRefExpr [[B]] {{.*}} 'int[2]' lvalue Var [[E]] 'A' 'int[2]'
+// CHECK: ImplicitCastExpr 0x{{.*}} {{.*}} 'int[2]' <HLSLArrayRValue>
+// CHECK: OpaqueValueExpr [[C]] {{.*}} 'int[2]' lvalue
+// CHECK: ImplicitCastExpr [[D]] {{.*}} 'int[2]' <HLSLArrayRValue>
+// CHECK: OpaqueValueExpr [[A]] {{.*}} 'int[2]' lvalue
+// CHECK: DeclRefExpr [[B]] {{.*}} 'int[2]' lvalue Var [[E]] 'A' 'int[2]'
+export int call2() {
+  int A[2] = { 0, 1 };
+  fn2(A);
+  return 1;
+}

clang/test/CodeGenHLSL/ArrayAssignable.hlsl

@@ -100,18 +100,16 @@ void arr_assign6() {
 }
 
 // CHECK-LABEL: define void {{.*}}arr_assign7
-// CHECK: [[Arr3:%.*]] = alloca [2 x [2 x i32]], align 4
-// CHECK-NEXT: [[Arr4:%.*]] = alloca [2 x [2 x i32]], align 4
-// CHECK-NEXT: [[Tmp:%.*]] = alloca [2 x i32], align 4
+// CHECK: [[Arr:%.*]] = alloca [2 x [2 x i32]], align 4
+// CHECK-NEXT: [[Arr2:%.*]] = alloca [2 x [2 x i32]], align 4
 // CHECK-NOT: alloca
-// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Arr3]], ptr align 4 {{@.*}}, i32 16, i1 false)
-// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Arr4]], ptr align 4 {{@.*}}, i32 16, i1 false)
-// CHECK-NEXT: store i32 6, ptr [[Tmp]], align 4
-// CHECK-NEXT: [[AIE:%.*]] = getelementptr inbounds i32, ptr [[Tmp]], i32 1
-// CHECK-NEXT: store i32 6, ptr [[AIE]], align 4
-// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Arr3]], ptr align 4 [[Arr4]], i32 16, i1 false)
-// CHECK-NEXT: [[Idx:%.*]] = getelementptr inbounds [2 x [2 x i32]], ptr [[Arr3]], i32 0, i32 0
-// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Idx]], ptr align 4 [[Tmp]], i32 8, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Arr]], ptr align 4 {{@.*}}, i32 16, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Arr2]], ptr align 4 {{@.*}}, i32 16, i1 false)
+// CHECK-NEXT: call void @llvm.memcpy.p0.p0.i32(ptr align 4 [[Arr]], ptr align 4 [[Arr2]], i32 16, i1 false)
+// CHECK-NEXT: [[Idx:%.*]] = getelementptr inbounds [2 x [2 x i32]], ptr [[Arr]], i32 0, i32 0
+// CHECK-NEXT: store i32 6, ptr [[Idx]], align 4
+// CHECK-NEXT: [[Idx2:%.*]] = getelementptr inbounds i32, ptr %arrayidx, i32 1
+// CHECK-NEXT: store i32 6, ptr [[Idx2]], align 4
 // CHECK-NEXT: ret void
 void arr_assign7() {
   int Arr[2][2] = {{0, 1}, {2, 3}};