[spirv-writer] Fixes to constant constructor determination.

The change from `cast` to type constructor casts causes our current
determination if a constructor is constant to no longer be correct.

This Cl updates the determination to match the current spec and adds a
bunch of unit tests to verify the behaviour..

Bug: tint:270
Change-Id: I8ce74eb7c3f849ce62815868313449d8ca2de6be
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/30020
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Sarah Mashayekhi <sarahmashay@google.com>
Commit-Queue: dan sinclair <dsinclair@chromium.org>

src/writer/spirv/builder.cc

@@ -1128,6 +1128,64 @@ uint32_t Builder::GenerateConstructorExpression(
   return 0;
 }
 
+bool Builder::is_constructor_const(ast::Expression* expr, bool is_global_init) {
+  if (!expr->IsConstructor()) {
+    return false;
+  }
+  if (expr->AsConstructor()->IsScalarConstructor()) {
+    return true;
+  }
+
+  auto* tc = expr->AsConstructor()->AsTypeConstructor();
+  auto* result_type = tc->type()->UnwrapAliasPtrAlias();
+  for (size_t i = 0; i < tc->values().size(); ++i) {
+    auto* e = tc->values()[i].get();
+
+    if (!e->IsConstructor()) {
+      if (is_global_init) {
+        error_ = "constructor must be a constant expression";
+        return false;
+      }
+      return false;
+    }
+    if (!is_constructor_const(e, is_global_init)) {
+      return false;
+    }
+    if (has_error()) {
+      return false;
+    }
+
+    if (result_type->IsVector() && !e->AsConstructor()->IsScalarConstructor()) {
+      return false;
+    }
+
+    // This should all be handled by |is_constructor_const| call above
+    if (!e->AsConstructor()->IsScalarConstructor()) {
+      continue;
+    }
+
+    auto* sc = e->AsConstructor()->AsScalarConstructor();
+    ast::type::Type* subtype = result_type->UnwrapAliasPtrAlias();
+    if (subtype->IsVector()) {
+      subtype = subtype->AsVector()->type()->UnwrapAliasPtrAlias();
+    } else if (subtype->IsMatrix()) {
+      subtype = subtype->AsMatrix()->type()->UnwrapAliasPtrAlias();
+    } else if (subtype->IsArray()) {
+      subtype = subtype->AsArray()->type()->UnwrapAliasPtrAlias();
+    } else if (subtype->IsStruct()) {
+      subtype = subtype->AsStruct()
+                    ->impl()
+                    ->members()[i]
+                    ->type()
+                    ->UnwrapAliasPtrAlias();
+    }
+    if (subtype != sc->result_type()->UnwrapAliasPtrAlias()) {
+      return false;
+    }
+  }
+  return true;
+}
+
 uint32_t Builder::GenerateTypeConstructorExpression(
     ast::TypeConstructorExpression* init,
     bool is_global_init) {
@@ -1143,30 +1201,13 @@ uint32_t Builder::GenerateTypeConstructorExpression(
   out << "__const";
 
   auto* result_type = init->type()->UnwrapAliasPtrAlias();
-
+  bool constructor_is_const = is_constructor_const(init, is_global_init);
-  OperandList ops;
+  if (has_error()) {
-  bool constructor_is_const = true;
-  for (const auto& e : values) {
-    if (!e->IsConstructor()) {
-      if (is_global_init) {
-        error_ = "constructor must be a constant expression";
     return 0;
   }
-      constructor_is_const = false;
-      break;
-    } else if (result_type->IsVector()) {
-      // Even if we have constructor parameters if the types are different then
-      // the constructor is not const as we'll generate OpBitcast or
-      // OpCopyObject instructions.
-      auto* subtype = result_type->AsVector()->type()->UnwrapAliasPtrAlias();
-      if (subtype != e->result_type()->UnwrapAliasPtrAlias()) {
-        constructor_is_const = false;
-        break;
-      }
-    }
-  }
 
   bool can_cast_or_copy = result_type->is_scalar();
+
   if (result_type->IsVector() && result_type->AsVector()->type()->is_scalar()) {
     auto* value_type = values[0]->result_type()->UnwrapAliasPtrAlias();
     can_cast_or_copy =
@@ -1190,6 +1231,7 @@ uint32_t Builder::GenerateTypeConstructorExpression(
     result_type = result_type->AsVector()->type();
   }
 
+  OperandList ops;
   for (const auto& e : values) {
     uint32_t id = 0;
     if (constructor_is_const) {

src/writer/spirv/builder.h

@@ -437,6 +437,12 @@ class Builder {
   SpvImageFormat convert_image_format_to_spv(
       const ast::type::ImageFormat format);
 
+  /// Determines if the given type constructor is created from constant values
+  /// @param expr the expression to check
+  /// @param is_global_init if this is a global initializer
+  /// @returns true if the constructor is constant
+  bool is_constructor_const(ast::Expression* expr, bool is_global_init);
+
  private:
   /// @returns an Operand with a new result ID in it. Increments the next_id_
   /// automatically.

src/writer/spirv/builder_assign_test.cc

@@ -178,7 +178,6 @@ OpStore %1 %13
 TEST_F(BuilderTest, Assign_Var_Complex_Constructor) {
   ast::type::F32Type f32;
   ast::type::VectorType vec3(&f32, 3);
-  ast::type::VectorType vec(&vec3, 3);
 
   ast::ExpressionList vals;
   vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
@@ -187,35 +186,11 @@ TEST_F(BuilderTest, Assign_Var_Complex_Constructor) {
       std::make_unique<ast::FloatLiteral>(&f32, 2.0f)));
   vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
       std::make_unique<ast::FloatLiteral>(&f32, 3.0f)));
-  auto first =
-      std::make_unique<ast::TypeConstructorExpression>(&vec3, std::move(vals));
-
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 3.0f)));
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 2.0f)));
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));
-  auto second =
-      std::make_unique<ast::TypeConstructorExpression>(&vec3, std::move(vals));
-
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 2.0f)));
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 3.0f)));
-  auto third =
-      std::make_unique<ast::TypeConstructorExpression>(&vec3, std::move(vals));
-
-  vals.push_back(std::move(first));
-  vals.push_back(std::move(second));
-  vals.push_back(std::move(third));
 
   auto init =
-      std::make_unique<ast::TypeConstructorExpression>(&vec, std::move(vals));
+      std::make_unique<ast::TypeConstructorExpression>(&vec3, std::move(vals));
 
-  ast::Variable v("var", ast::StorageClass::kOutput, &vec);
+  ast::Variable v("var", ast::StorageClass::kOutput, &vec3);
 
   ast::AssignmentStatement assign(
       std::make_unique<ast::IdentifierExpression>("var"), std::move(init));
@@ -234,21 +209,17 @@ TEST_F(BuilderTest, Assign_Var_Complex_Constructor) {
   EXPECT_TRUE(b.GenerateAssignStatement(&assign)) << b.error();
   EXPECT_FALSE(b.has_error());
 
-  EXPECT_EQ(DumpInstructions(b.types()), R"(%5 = OpTypeFloat 32
+  EXPECT_EQ(DumpInstructions(b.types()), R"(%4 = OpTypeFloat 32
-%4 = OpTypeVector %5 3
 %3 = OpTypeVector %4 3
 %2 = OpTypePointer Output %3
-%6 = OpConstantNull %3
+%5 = OpConstantNull %3
-%1 = OpVariable %2 Output %6
+%1 = OpVariable %2 Output %5
-%7 = OpConstant %5 1
+%6 = OpConstant %4 1
-%8 = OpConstant %5 2
+%7 = OpConstant %4 2
-%9 = OpConstant %5 3
+%8 = OpConstant %4 3
-%10 = OpConstantComposite %4 %7 %8 %9
+%9 = OpConstantComposite %3 %6 %7 %8
-%11 = OpConstantComposite %4 %9 %8 %7
-%12 = OpConstantComposite %4 %8 %7 %9
-%13 = OpConstantComposite %3 %10 %11 %12
 )");
-  EXPECT_EQ(DumpInstructions(b.functions()[0].instructions()), R"(OpStore %1 %13
+  EXPECT_EQ(DumpInstructions(b.functions()[0].instructions()), R"(OpStore %1 %9
 )");
 }
 

src/writer/spirv/builder_constructor_expression_test.cc

@@ -95,6 +95,49 @@ TEST_F(BuilderTest, Constructor_Type) {
 )");
 }
 
+TEST_F(BuilderTest, Constructor_Type_WithCasts) {
+  ast::type::F32Type f32;
+  ast::type::I32Type i32;
+  ast::type::VectorType vec(&f32, 2);
+
+  ast::ExpressionList type_vals;
+  type_vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 1)));
+
+  ast::ExpressionList vals;
+  vals.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(type_vals)));
+
+  type_vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 1)));
+  vals.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(type_vals)));
+
+  ast::TypeConstructorExpression t(&vec, std::move(vals));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  EXPECT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  b.push_function(Function{});
+
+  EXPECT_EQ(b.GenerateExpression(&t), 7u);
+  ASSERT_FALSE(b.has_error()) << b.error();
+
+  EXPECT_EQ(DumpInstructions(b.types()), R"(%2 = OpTypeFloat 32
+%1 = OpTypeVector %2 2
+%4 = OpTypeInt 32 1
+%5 = OpConstant %4 1
+)");
+  EXPECT_EQ(DumpInstructions(b.functions()[0].instructions()),
+            R"(%3 = OpConvertSToF %2 %5
+%6 = OpConvertSToF %2 %5
+%7 = OpCompositeConstruct %1 %3 %6
+)");
+}
+
 TEST_F(BuilderTest, Constructor_Type_WithAlias) {
   ast::type::I32Type i32;
   ast::type::F32Type f32;
@@ -2384,6 +2427,407 @@ TEST_F(BuilderTest, Constructor_Type_Convert_Vectors_U32_to_F32) {
 )");
 }
 
+TEST_F(BuilderTest, IsConstructorConst_GlobalVectorWithAllConstConstructors) {
+  // vec3<f32>(1.0, 2.0, 3.0)  -> true
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 3.f)));
+  ast::TypeConstructorExpression t(&vec, std::move(params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_TRUE(b.is_constructor_const(&t, true));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_GlobalVector_WithIdent) {
+  // vec3<f32>(a, b, c)  -> false -- ERROR
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::IdentifierExpression>("a"));
+  params.push_back(std::make_unique<ast::IdentifierExpression>("b"));
+  params.push_back(std::make_unique<ast::IdentifierExpression>("c"));
+  ast::TypeConstructorExpression t(&vec, std::move(params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_FALSE(b.is_constructor_const(&t, true));
+  EXPECT_TRUE(b.has_error());
+  EXPECT_EQ(b.error(), "constructor must be a constant expression");
+}
+
+TEST_F(BuilderTest, IsConstructorConst_GlobalArrayWithAllConstConstructors) {
+  // array<vec3<f32>, 2>(vec3<f32>(1.0, 2.0, 3.0), vec3<f32>(1.0, 2.0, 3.0))
+  //   -> true
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+  ast::type::ArrayType ary(&vec, 2);
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 3.f)));
+  auto first =
+      std::make_unique<ast::TypeConstructorExpression>(&vec, std::move(params));
+
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 3.f)));
+  auto second =
+      std::make_unique<ast::TypeConstructorExpression>(&vec, std::move(params));
+
+  ast::ExpressionList ary_params;
+  ary_params.push_back(std::move(first));
+  ary_params.push_back(std::move(second));
+  ast::TypeConstructorExpression t(&ary, std::move(ary_params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_TRUE(b.is_constructor_const(&t, true));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest,
+       IsConstructorConst_GlobalVectorWithMatchingTypeConstructors) {
+  // vec3<f32>(f32(1.0), f32(2.0))  -> false
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 2);
+
+  ast::ExpressionList vec_params;
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.0)));
+  vec_params.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(params)));
+
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2.0)));
+  vec_params.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(params)));
+
+  ast::TypeConstructorExpression t(&vec, std::move(vec_params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_FALSE(b.is_constructor_const(&t, true));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_GlobalWithTypeCastConstructor) {
+  // vec3<f32>(f32(1), f32(2)) -> false
+  ast::type::F32Type f32;
+  ast::type::I32Type i32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::ExpressionList vec_params;
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 1)));
+  vec_params.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(params)));
+
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 2)));
+  vec_params.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(params)));
+
+  ast::TypeConstructorExpression t(&vec, std::move(vec_params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_FALSE(b.is_constructor_const(&t, true));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_VectorWithAllConstConstructors) {
+  // vec3<f32>(1.0, 2.0, 3.0)  -> true
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 3.f)));
+  ast::TypeConstructorExpression t(&vec, std::move(params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_TRUE(b.is_constructor_const(&t, false));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_Vector_WithIdent) {
+  // vec3<f32>(a, b, c)  -> false
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::IdentifierExpression>("a"));
+  params.push_back(std::make_unique<ast::IdentifierExpression>("b"));
+  params.push_back(std::make_unique<ast::IdentifierExpression>("c"));
+  ast::TypeConstructorExpression t(&vec, std::move(params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_FALSE(b.is_constructor_const(&t, false));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_ArrayWithAllConstConstructors) {
+  // array<vec3<f32>, 2>(vec3<f32>(1.0, 2.0, 3.0), vec3<f32>(1.0, 2.0, 3.0))
+  //   -> true
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+  ast::type::ArrayType ary(&vec, 2);
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 3.f)));
+  auto first =
+      std::make_unique<ast::TypeConstructorExpression>(&vec, std::move(params));
+
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 1.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2.f)));
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 3.f)));
+  auto second =
+      std::make_unique<ast::TypeConstructorExpression>(&vec, std::move(params));
+
+  ast::ExpressionList ary_params;
+  ary_params.push_back(std::move(first));
+  ary_params.push_back(std::move(second));
+  ast::TypeConstructorExpression t(&ary, std::move(ary_params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_TRUE(b.is_constructor_const(&t, false));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_VectorWith_TypeCastConstConstructors) {
+  // vec2<f32>(f32(1.0), f32(2.0))  -> false
+  ast::type::F32Type f32;
+  ast::type::I32Type i32;
+  ast::type::VectorType vec(&f32, 2);
+
+  ast::ExpressionList vec_params;
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 1)));
+  vec_params.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(params)));
+
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 2)));
+  vec_params.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(params)));
+
+  ast::TypeConstructorExpression t(&vec, std::move(vec_params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_FALSE(b.is_constructor_const(&t, false));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_WithTypeCastConstructor) {
+  // vec3<f32>(f32(1), f32(2)) -> false
+  ast::type::F32Type f32;
+  ast::type::I32Type i32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::ExpressionList vec_params;
+
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 1)));
+  vec_params.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(params)));
+
+  params.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 2)));
+  vec_params.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &f32, std::move(params)));
+
+  ast::TypeConstructorExpression t(&vec, std::move(vec_params));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_FALSE(b.is_constructor_const(&t, false));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_BitCastScalars) {
+  ast::type::I32Type i32;
+  ast::type::U32Type u32;
+  ast::type::VectorType vec(&u32, 2);
+
+  ast::ExpressionList vals;
+  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 1)));
+  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::SintLiteral>(&i32, 1)));
+
+  ast::TypeConstructorExpression t(&vec, std::move(vals));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_FALSE(b.is_constructor_const(&t, false));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_Struct) {
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::StructMemberDecorationList decos;
+  ast::StructMemberList members;
+  members.push_back(
+      std::make_unique<ast::StructMember>("a", &f32, std::move(decos)));
+  members.push_back(
+      std::make_unique<ast::StructMember>("b", &vec, std::move(decos)));
+
+  auto s = std::make_unique<ast::Struct>(std::move(members));
+  ast::type::StructType s_type(std::move(s));
+  s_type.set_name("my_struct");
+
+  ast::ExpressionList vec_vals;
+  vec_vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2)));
+  vec_vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2)));
+  vec_vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2)));
+
+  ast::ExpressionList vals;
+  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2)));
+  vals.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &vec, std::move(vec_vals)));
+
+  ast::TypeConstructorExpression t(&s_type, std::move(vals));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_TRUE(b.is_constructor_const(&t, false));
+  EXPECT_FALSE(b.has_error());
+}
+
+TEST_F(BuilderTest, IsConstructorConst_Struct_WithIdentSubExpression) {
+  ast::type::F32Type f32;
+  ast::type::VectorType vec(&f32, 3);
+
+  ast::StructMemberDecorationList decos;
+  ast::StructMemberList members;
+  members.push_back(
+      std::make_unique<ast::StructMember>("a", &f32, std::move(decos)));
+  members.push_back(
+      std::make_unique<ast::StructMember>("b", &vec, std::move(decos)));
+
+  auto s = std::make_unique<ast::Struct>(std::move(members));
+  ast::type::StructType s_type(std::move(s));
+  s_type.set_name("my_struct");
+
+  ast::ExpressionList vec_vals;
+  vec_vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2)));
+  vec_vals.push_back(std::make_unique<ast::IdentifierExpression>("a"));
+  vec_vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2)));
+
+  ast::ExpressionList vals;
+  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2)));
+  vals.push_back(std::make_unique<ast::TypeConstructorExpression>(
+      &vec, std::move(vec_vals)));
+
+  ast::TypeConstructorExpression t(&s_type, std::move(vals));
+
+  Context ctx;
+  ast::Module mod;
+  TypeDeterminer td(&ctx, &mod);
+  ASSERT_TRUE(td.DetermineResultType(&t)) << td.error();
+
+  Builder b(&mod);
+  EXPECT_FALSE(b.is_constructor_const(&t, false));
+  EXPECT_FALSE(b.has_error());
+}
+
 }  // namespace
 }  // namespace spirv
 }  // namespace writer

src/writer/spirv/builder_global_variable_test.cc

@@ -176,7 +176,6 @@ TEST_F(BuilderTest, GlobalVar_Const) {
 TEST_F(BuilderTest, GlobalVar_Complex_Constructor) {
   ast::type::F32Type f32;
   ast::type::VectorType vec3(&f32, 3);
-  ast::type::VectorType vec(&vec3, 3);
 
   ast::ExpressionList vals;
   vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
@@ -185,33 +184,8 @@ TEST_F(BuilderTest, GlobalVar_Complex_Constructor) {
       std::make_unique<ast::FloatLiteral>(&f32, 2.0f)));
   vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
       std::make_unique<ast::FloatLiteral>(&f32, 3.0f)));
-  auto first =
-      std::make_unique<ast::TypeConstructorExpression>(&vec3, std::move(vals));
-
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 3.0f)));
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 2.0f)));
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));
-  auto second =
-      std::make_unique<ast::TypeConstructorExpression>(&vec3, std::move(vals));
-
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 2.0f)));
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));
-  vals.push_back(std::make_unique<ast::ScalarConstructorExpression>(
-      std::make_unique<ast::FloatLiteral>(&f32, 3.0f)));
-  auto third =
-      std::make_unique<ast::TypeConstructorExpression>(&vec3, std::move(vals));
-
-  vals.push_back(std::move(first));
-  vals.push_back(std::move(second));
-  vals.push_back(std::move(third));
-
   auto init =
-      std::make_unique<ast::TypeConstructorExpression>(&vec, std::move(vals));
+      std::make_unique<ast::TypeConstructorExpression>(&vec3, std::move(vals));
 
   Context ctx;
   ast::Module mod;
@@ -227,16 +201,12 @@ TEST_F(BuilderTest, GlobalVar_Complex_Constructor) {
   EXPECT_TRUE(b.GenerateGlobalVariable(&v)) << b.error();
   ASSERT_FALSE(b.has_error()) << b.error();
 
-  EXPECT_EQ(DumpInstructions(b.types()), R"(%3 = OpTypeFloat 32
+  EXPECT_EQ(DumpInstructions(b.types()), R"(%2 = OpTypeFloat 32
-%2 = OpTypeVector %3 3
 %1 = OpTypeVector %2 3
-%4 = OpConstant %3 1
+%3 = OpConstant %2 1
-%5 = OpConstant %3 2
+%4 = OpConstant %2 2
-%6 = OpConstant %3 3
+%5 = OpConstant %2 3
-%7 = OpConstantComposite %2 %4 %5 %6
+%6 = OpConstantComposite %1 %3 %4 %5
-%8 = OpConstantComposite %2 %6 %5 %4
-%9 = OpConstantComposite %2 %5 %4 %6
-%10 = OpConstantComposite %1 %7 %8 %9
 )");
 }