[HLSL] Add matrix constructors using initalizer lists

fixes #159434

In HLSL matrices are matrix_type in all respects except that they support a constructor style syntax for initializing matrices.

This change adds a translation of vector constructor arguments into initializer lists.

This supports the following HLSL syntax:
(1) HLSL matrices support constructor syntax
(2) HLSL matrices are expanded to constituate components in constructor

using the same initalizer list behavior defined in transformInitList
allows us to support struct element initalization via HLSLElementwiseCast

Author: farzonl

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -2418,9 +2418,9 @@ def err_init_conversion_failed : Error<
   "cannot initialize %select{a variable|a parameter|template parameter|"
   "return object|statement expression result|an "
   "exception object|a member subobject|an array element|a new value|a value|a "
-  "base class|a constructor delegation|a vector element|a block element|a "
-  "block element|a complex element|a lambda capture|a compound literal "
-  "initializer|a related result|a parameter of CF audited function|a "
+  "base class|a constructor delegation|a vector element|a matrix element|a "
+  "block element|a block element|a complex element|a lambda capture|a compound"
+  " literal initializer|a related result|a parameter of CF audited function|a "
   "structured binding|a member subobject}0 "
   "%diff{of type $ with an %select{rvalue|lvalue}2 of type $|"
   "with an %select{rvalue|lvalue}2 of incompatible type}1,3"
@@ -6543,9 +6543,9 @@ def warn_extern_init : Warning<"'extern' variable has an initializer">,
 def err_variable_object_no_init : Error<
   "variable-sized object may not be initialized">;
 def err_excess_initializers : Error<
-  "excess elements in %select{array|vector|scalar|union|struct}0 initializer">;
+  "excess elements in %select{array|vector|matrix|scalar|union|struct}0 initializer">;
 def ext_excess_initializers : ExtWarn<
-  "excess elements in %select{array|vector|scalar|union|struct}0 initializer">,
+  "excess elements in %select{array|vector|matrix|scalar|union|struct}0 initializer">,
   InGroup<ExcessInitializers>;
 def err_excess_initializers_for_sizeless_type : Error<
   "excess elements in initializer for indivisible sizeless type %0">;
@@ -11086,8 +11086,8 @@ def err_first_argument_to_cwsc_pdtor_call : Error<
 def err_second_argument_to_cwsc_not_pointer : Error<
   "second argument to __builtin_call_with_static_chain must be of pointer type">;
 
-def err_vector_incorrect_num_elements : Error<
-  "%select{too many|too few}0 elements in vector %select{initialization|operand}3 (expected %1 elements, have %2)">;
+def err_tensor_incorrect_num_elements : Error<
+  "%select{too many|too few}0 elements in %select{vector|matrix}1 %select{initialization|operand}4 (expected %2 elements, have %3)">;
 def err_altivec_empty_initializer : Error<"expected initializer">;
 
 def err_vector_incorrect_bit_count : Error<

clang/include/clang/Sema/Initialization.h

@@ -91,6 +91,10 @@ class alignas(8) InitializedEntity {
     /// or vector.
     EK_VectorElement,
 
+    /// The entity being initialized is an element of a matrix.
+    /// or matrix.
+    EK_MatrixElement,
+
     /// The entity being initialized is a field of block descriptor for
     /// the copied-in c++ object.
     EK_BlockElement,
@@ -205,8 +209,8 @@ class alignas(8) InitializedEntity {
     /// virtual base.
     llvm::PointerIntPair<const CXXBaseSpecifier *, 1> Base;
 
-    /// When Kind == EK_ArrayElement, EK_VectorElement, or
-    /// EK_ComplexElement, the index of the array or vector element being
+    /// When Kind == EK_ArrayElement, EK_VectorElement, or EK_MatrixElement,
+    /// or EK_ComplexElement, the index of the array or vector element being
     /// initialized.
     unsigned Index;
 
@@ -536,15 +540,15 @@ class alignas(8) InitializedEntity {
   /// element's index.
   unsigned getElementIndex() const {
     assert(getKind() == EK_ArrayElement || getKind() == EK_VectorElement ||
-           getKind() == EK_ComplexElement);
+           getKind() == EK_MatrixElement || getKind() == EK_ComplexElement);
     return Index;
   }
 
   /// If this is already the initializer for an array or vector
   /// element, sets the element index.
   void setElementIndex(unsigned Index) {
     assert(getKind() == EK_ArrayElement || getKind() == EK_VectorElement ||
-           getKind() == EK_ComplexElement);
+           getKind() == EK_MatrixElement || getKind() == EK_ComplexElement);
     this->Index = Index;
   }
 

clang/lib/Sema/CheckExprLifetime.cpp

@@ -155,6 +155,7 @@ getEntityLifetime(const InitializedEntity *Entity,
   case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
   case InitializedEntity::EK_LambdaCapture:
   case InitializedEntity::EK_VectorElement:
+  case InitializedEntity::EK_MatrixElement:
   case InitializedEntity::EK_ComplexElement:
     return {nullptr, LK_FullExpression};
 

clang/lib/Sema/SemaHLSL.cpp

@@ -21,6 +21,7 @@
 #include "clang/AST/Expr.h"
 #include "clang/AST/HLSLResource.h"
 #include "clang/AST/Type.h"
+#include "clang/AST/TypeBase.h"
 #include "clang/AST/TypeLoc.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/DiagnosticSema.h"
@@ -3323,6 +3324,11 @@ static void BuildFlattenedTypeList(QualType BaseTy,
       List.insert(List.end(), VT->getNumElements(), VT->getElementType());
       continue;
     }
+    if (const auto *MT = dyn_cast<ConstantMatrixType>(T)) {
+      List.insert(List.end(), MT->getNumElementsFlattened(),
+                  MT->getElementType());
+      continue;
+    }
     if (const auto *RD = T->getAsCXXRecordDecl()) {
       if (RD->isStandardLayout())
         RD = RD->getStandardLayoutBaseWithFields();
@@ -4124,6 +4130,32 @@ class InitListTransformer {
       }
       return true;
     }
+    if (auto *MTy = Ty->getAs<ConstantMatrixType>()) {
+      unsigned Rows = MTy->getNumRows();
+      unsigned Cols = MTy->getNumColumns();
+      QualType ElemTy = MTy->getElementType();
+
+      for (unsigned C = 0; C < Cols; ++C) {
+        for (unsigned R = 0; R < Rows; ++R) {
+          // row index literal
+          Expr *RowIdx = IntegerLiteral::Create(
+              Ctx, llvm::APInt(Ctx.getIntWidth(Ctx.IntTy), R), Ctx.IntTy,
+              E->getBeginLoc());
+          // column index literal
+          Expr *ColIdx = IntegerLiteral::Create(
+              Ctx, llvm::APInt(Ctx.getIntWidth(Ctx.IntTy), C), Ctx.IntTy,
+              E->getBeginLoc());
+          ExprResult ElExpr = S.CreateBuiltinMatrixSubscriptExpr(
+              E, RowIdx, ColIdx, E->getEndLoc());
+          if (ElExpr.isInvalid())
+            return false;
+          if (!buildInitializerListImpl(ElExpr.get()))
+            return false;
+          ElExpr.get()->setType(ElemTy);
+        }
+      }
+      return true;
+    }
 
     if (auto *ArrTy = dyn_cast<ConstantArrayType>(Ty.getTypePtr())) {
       uint64_t Size = ArrTy->getZExtSize();
@@ -4177,14 +4209,17 @@ class InitListTransformer {
       return *(ArgIt++);
 
     llvm::SmallVector<Expr *> Inits;
-    assert(!isa<MatrixType>(Ty) && "Matrix types not yet supported in HLSL");
     Ty = Ty.getDesugaredType(Ctx);
-    if (Ty->isVectorType() || Ty->isConstantArrayType()) {
+    if (Ty->isVectorType() || Ty->isConstantArrayType() ||
+        Ty->isConstantMatrixType()) {
       QualType ElTy;
       uint64_t Size = 0;
       if (auto *ATy = Ty->getAs<VectorType>()) {
         ElTy = ATy->getElementType();
         Size = ATy->getNumElements();
+      } else if (auto *CMTy = Ty->getAs<ConstantMatrixType>()) {
+        ElTy = CMTy->getElementType();
+        Size = CMTy->getNumElementsFlattened();
       } else {
         auto *VTy = cast<ConstantArrayType>(Ty.getTypePtr());
         ElTy = VTy->getElementType();