Add instance step mode to vertex pulling transform
Bug: dawn:480
Change-Id: Icf650b7f340528e6a49d68d155fd9becc212e623
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/26440
Reviewed-by: dan sinclair <dsinclair@chromium.org>
Commit-Queue: dan sinclair <dsinclair@chromium.org>
diff --git a/src/ast/transform/vertex_pulling_transform.cc b/src/ast/transform/vertex_pulling_transform.cc
index fc571d5..528c7e5 100644
--- a/src/ast/transform/vertex_pulling_transform.cc
+++ b/src/ast/transform/vertex_pulling_transform.cc
@@ -48,6 +48,7 @@
static const char kStructBufferName[] = "data";
static const char kPullingPosVarName[] = "tint_pulling_pos";
static const char kDefaultVertexIndexName[] = "tint_pulling_vertex_index";
+static const char kDefaultInstanceIndexName[] = "tint_pulling_instance_index";
} // namespace
VertexPullingTransform::VertexPullingTransform(Context* ctx, Module* mod)
@@ -100,7 +101,8 @@
// TODO(idanr): Make sure we covered all error cases, to guarantee the
// following stages will pass
- FindOrInsertVertexIndex();
+ FindOrInsertVertexIndexIfUsed();
+ FindOrInsertInstanceIndexIfUsed();
ConvertVertexInputVariablesToPrivate();
AddVertexStorageBuffers();
AddVertexPullingPreamble(vertex_func);
@@ -116,7 +118,19 @@
return kVertexBufferNamePrefix + std::to_string(index);
}
-void VertexPullingTransform::FindOrInsertVertexIndex() {
+void VertexPullingTransform::FindOrInsertVertexIndexIfUsed() {
+ bool uses_vertex_step_mode = false;
+ for (const VertexBufferLayoutDescriptor& buffer_layout :
+ vertex_state_->vertex_buffers) {
+ if (buffer_layout.step_mode == InputStepMode::kVertex) {
+ uses_vertex_step_mode = true;
+ break;
+ }
+ }
+ if (!uses_vertex_step_mode) {
+ return;
+ }
+
// Look for an existing vertex index builtin
for (auto& v : mod_->global_variables()) {
if (!v->IsDecorated() || v->storage_class() != StorageClass::kInput) {
@@ -145,6 +159,47 @@
mod_->AddGlobalVariable(std::move(var));
}
+void VertexPullingTransform::FindOrInsertInstanceIndexIfUsed() {
+ bool uses_instance_step_mode = false;
+ for (const VertexBufferLayoutDescriptor& buffer_layout :
+ vertex_state_->vertex_buffers) {
+ if (buffer_layout.step_mode == InputStepMode::kInstance) {
+ uses_instance_step_mode = true;
+ break;
+ }
+ }
+ if (!uses_instance_step_mode) {
+ return;
+ }
+
+ // Look for an existing instance index builtin
+ for (auto& v : mod_->global_variables()) {
+ if (!v->IsDecorated() || v->storage_class() != StorageClass::kInput) {
+ continue;
+ }
+
+ for (auto& d : v->AsDecorated()->decorations()) {
+ if (d->IsBuiltin() && d->AsBuiltin()->value() == Builtin::kInstanceIdx) {
+ instance_index_name_ = v->name();
+ return;
+ }
+ }
+ }
+
+ // We didn't find an instance index builtin, so create one
+ instance_index_name_ = kDefaultInstanceIndexName;
+
+ auto var = std::make_unique<DecoratedVariable>(std::make_unique<Variable>(
+ instance_index_name_, StorageClass::kInput, GetI32Type()));
+
+ VariableDecorationList decorations;
+ decorations.push_back(
+ std::make_unique<BuiltinDecoration>(Builtin::kInstanceIdx));
+
+ var->set_decorations(std::move(decorations));
+ mod_->AddGlobalVariable(std::move(var));
+}
+
void VertexPullingTransform::ConvertVertexInputVariablesToPrivate() {
for (auto& v : mod_->global_variables()) {
if (!v->IsDecorated() || v->storage_class() != StorageClass::kInput) {
@@ -228,12 +283,17 @@
}
auto* v = it->second;
+ // Identifier to index by
+ auto index_identifier = std::make_unique<IdentifierExpression>(
+ buffer_layout.step_mode == InputStepMode::kVertex
+ ? vertex_index_name_
+ : instance_index_name_);
+
// An expression for the start of the read in the buffer in bytes
auto pos_value = std::make_unique<BinaryExpression>(
BinaryOp::kAdd,
std::make_unique<BinaryExpression>(
- BinaryOp::kMultiply,
- std::make_unique<IdentifierExpression>(vertex_index_name_),
+ BinaryOp::kMultiply, std::move(index_identifier),
GenUint(static_cast<uint32_t>(buffer_layout.array_stride))),
GenUint(static_cast<uint32_t>(attribute_desc.offset)));
diff --git a/src/ast/transform/vertex_pulling_transform.h b/src/ast/transform/vertex_pulling_transform.h
index 636ddc4..4ad6321 100644
--- a/src/ast/transform/vertex_pulling_transform.h
+++ b/src/ast/transform/vertex_pulling_transform.h
@@ -159,7 +159,10 @@
std::string GetVertexBufferName(uint32_t index);
/// Inserts vertex_idx binding, or finds the existing one
- void FindOrInsertVertexIndex();
+ void FindOrInsertVertexIndexIfUsed();
+
+ /// Inserts instance_idx binding, or finds the existing one
+ void FindOrInsertInstanceIndexIfUsed();
/// Converts var<in> with a location decoration to var<private>
void ConvertVertexInputVariablesToPrivate();
@@ -237,6 +240,7 @@
std::string error_;
std::string vertex_index_name_;
+ std::string instance_index_name_;
std::unordered_map<uint32_t, Variable*> location_to_var_;
std::unique_ptr<VertexStateDescriptor> vertex_state_;
diff --git a/src/ast/transform/vertex_pulling_transform_test.cc b/src/ast/transform/vertex_pulling_transform_test.cc
index c0cc841..cafefda 100644
--- a/src/ast/transform/vertex_pulling_transform_test.cc
+++ b/src/ast/transform/vertex_pulling_transform_test.cc
@@ -201,27 +201,14 @@
mod()->to_str());
}
-// We expect the transform to use an existing vertex_idx builtin variable if it
-// finds one
-TEST_F(VertexPullingTransformTest, ExistingVertexIndex) {
+TEST_F(VertexPullingTransformTest, OneInstancedAttribute) {
InitBasicModule();
type::F32Type f32;
AddVertexInputVariable(0, "var_a", &f32);
- type::I32Type i32;
- auto vertex_index_var =
- std::make_unique<DecoratedVariable>(std::make_unique<Variable>(
- "custom_vertex_index", StorageClass::kInput, &i32));
-
- VariableDecorationList decorations;
- decorations.push_back(
- std::make_unique<BuiltinDecoration>(Builtin::kVertexIdx));
-
- vertex_index_var->set_decorations(std::move(decorations));
- mod()->AddGlobalVariable(std::move(vertex_index_var));
-
- InitTransform({{{4, InputStepMode::kVertex, {{VertexFormat::kF32, 0, 0}}}}});
+ InitTransform(
+ {{{4, InputStepMode::kInstance, {{VertexFormat::kF32, 0, 0}}}}});
EXPECT_TRUE(transform()->Run());
@@ -233,6 +220,122 @@
}
DecoratedVariable{
Decorations{
+ BuiltinDecoration{instance_idx}
+ }
+ tint_pulling_instance_index
+ in
+ __i32
+ }
+ DecoratedVariable{
+ Decorations{
+ BindingDecoration{0}
+ SetDecoration{0}
+ }
+ tint_pulling_vertex_buffer_0
+ storage_buffer
+ __struct_
+ }
+ EntryPoint{vertex as main = vtx_main}
+ Function vtx_main -> __void
+ ()
+ {
+ Block{
+ VariableDeclStatement{
+ Variable{
+ tint_pulling_pos
+ function
+ __i32
+ }
+ }
+ Assignment{
+ Identifier{tint_pulling_pos}
+ Binary{
+ Binary{
+ Identifier{tint_pulling_instance_index}
+ multiply
+ ScalarConstructor{4}
+ }
+ add
+ ScalarConstructor{0}
+ }
+ }
+ Assignment{
+ Identifier{var_a}
+ As<__f32>{
+ ArrayAccessor{
+ MemberAccessor{
+ Identifier{tint_pulling_vertex_buffer_0}
+ Identifier{data}
+ }
+ Binary{
+ Identifier{tint_pulling_pos}
+ divide
+ ScalarConstructor{4}
+ }
+ }
+ }
+ }
+ }
+ }
+}
+)",
+ mod()->to_str());
+}
+
+// We expect the transform to use an existing builtin variables if it finds them
+TEST_F(VertexPullingTransformTest, ExistingVertexIndexAndInstanceIndex) {
+ InitBasicModule();
+
+ type::F32Type f32;
+ AddVertexInputVariable(0, "var_a", &f32);
+ AddVertexInputVariable(1, "var_b", &f32);
+
+ type::I32Type i32;
+ {
+ auto vertex_index_var =
+ std::make_unique<DecoratedVariable>(std::make_unique<Variable>(
+ "custom_vertex_index", StorageClass::kInput, &i32));
+
+ VariableDecorationList decorations;
+ decorations.push_back(
+ std::make_unique<BuiltinDecoration>(Builtin::kVertexIdx));
+
+ vertex_index_var->set_decorations(std::move(decorations));
+ mod()->AddGlobalVariable(std::move(vertex_index_var));
+ }
+
+ {
+ auto instance_index_var =
+ std::make_unique<DecoratedVariable>(std::make_unique<Variable>(
+ "custom_instance_index", StorageClass::kInput, &i32));
+
+ VariableDecorationList decorations;
+ decorations.push_back(
+ std::make_unique<BuiltinDecoration>(Builtin::kInstanceIdx));
+
+ instance_index_var->set_decorations(std::move(decorations));
+ mod()->AddGlobalVariable(std::move(instance_index_var));
+ }
+
+ InitTransform(
+ {{{4, InputStepMode::kVertex, {{VertexFormat::kF32, 0, 0}}},
+ {4, InputStepMode::kInstance, {{VertexFormat::kF32, 0, 1}}}}});
+
+ EXPECT_TRUE(transform()->Run());
+
+ EXPECT_EQ(R"(Module{
+ Variable{
+ var_a
+ private
+ __f32
+ }
+ Variable{
+ var_b
+ private
+ __f32
+ }
+ DecoratedVariable{
+ Decorations{
BuiltinDecoration{vertex_idx}
}
custom_vertex_index
@@ -241,6 +344,14 @@
}
DecoratedVariable{
Decorations{
+ BuiltinDecoration{instance_idx}
+ }
+ custom_instance_index
+ in
+ __i32
+ }
+ DecoratedVariable{
+ Decorations{
BindingDecoration{0}
SetDecoration{0}
}
@@ -248,6 +359,15 @@
storage_buffer
__struct_
}
+ DecoratedVariable{
+ Decorations{
+ BindingDecoration{1}
+ SetDecoration{0}
+ }
+ tint_pulling_vertex_buffer_1
+ storage_buffer
+ __struct_
+ }
EntryPoint{vertex as main = vtx_main}
Function vtx_main -> __void
()
@@ -288,6 +408,34 @@
}
}
}
+ Assignment{
+ Identifier{tint_pulling_pos}
+ Binary{
+ Binary{
+ Identifier{custom_instance_index}
+ multiply
+ ScalarConstructor{4}
+ }
+ add
+ ScalarConstructor{0}
+ }
+ }
+ Assignment{
+ Identifier{var_b}
+ As<__f32>{
+ ArrayAccessor{
+ MemberAccessor{
+ Identifier{tint_pulling_vertex_buffer_1}
+ Identifier{data}
+ }
+ Binary{
+ Identifier{tint_pulling_pos}
+ divide
+ ScalarConstructor{4}
+ }
+ }
+ }
+ }
}
}
}
