Emit UnaryDerivative in WGSL writer.
This CL updates the WGSL writer to emit the unary derivative expression.
Bug: tint:4
Change-Id: I18c0fd56d88f98a6c5d37e176d98ab7b3077a50c
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/17120
Reviewed-by: David Neto <dneto@google.com>
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 97c9a32..e8c005c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -416,6 +416,7 @@
writer/wgsl/generator_impl_member_accessor_test.cc
writer/wgsl/generator_impl_relational_test.cc
writer/wgsl/generator_impl_type_test.cc
+ writer/wgsl/generator_impl_unary_derivative_test.cc
writer/wgsl/generator_impl_variable_test.cc
)
endif()
diff --git a/src/writer/wgsl/generator_impl.cc b/src/writer/wgsl/generator_impl.cc
index f60126e..9e6a1be 100644
--- a/src/writer/wgsl/generator_impl.cc
+++ b/src/writer/wgsl/generator_impl.cc
@@ -44,6 +44,7 @@
#include "src/ast/type/vector_type.h"
#include "src/ast/type_initializer_expression.h"
#include "src/ast/uint_literal.h"
+#include "src/ast/unary_derivative_expression.h"
namespace tint {
namespace writer {
@@ -144,6 +145,9 @@
if (expr->IsRelational()) {
return EmitRelational(expr->AsRelational());
}
+ if (expr->IsUnaryDerivative()) {
+ return EmitUnaryDerivative(expr->AsUnaryDerivative());
+ }
error_ = "unknown expression type";
return false;
@@ -535,6 +539,33 @@
return true;
}
+bool GeneratorImpl::EmitUnaryDerivative(ast::UnaryDerivativeExpression* expr) {
+ switch (expr->op()) {
+ case ast::UnaryDerivative::kDpdx:
+ out_ << "dpdx";
+ break;
+ case ast::UnaryDerivative::kDpdy:
+ out_ << "dpdy";
+ break;
+ case ast::UnaryDerivative::kFwidth:
+ out_ << "fwidth";
+ break;
+ }
+
+ if (expr->modifier() != ast::DerivativeModifier::kNone) {
+ out_ << "<" << expr->modifier() << ">";
+ }
+
+ out_ << "(";
+
+ if (!EmitExpression(expr->param())) {
+ return false;
+ }
+
+ out_ << ")";
+ return true;
+}
+
} // namespace wgsl
} // namespace writer
} // namespace tint
diff --git a/src/writer/wgsl/generator_impl.h b/src/writer/wgsl/generator_impl.h
index 698de59..c2836a2 100644
--- a/src/writer/wgsl/generator_impl.h
+++ b/src/writer/wgsl/generator_impl.h
@@ -126,6 +126,10 @@
/// @param expr the type initializer expression
/// @returns true if the initializer is emitted
bool EmitTypeInitializer(ast::TypeInitializerExpression* expr);
+ /// Handles a unary derivative expression
+ /// @param expr the expression to emit
+ /// @returns true if the expressionw as emitted
+ bool EmitUnaryDerivative(ast::UnaryDerivativeExpression* expr);
/// Handles generating a variable
/// @param var the variable to generate
/// @returns true if the variable was emitted
diff --git a/src/writer/wgsl/generator_impl_unary_derivative_test.cc b/src/writer/wgsl/generator_impl_unary_derivative_test.cc
new file mode 100644
index 0000000..b7af8dc
--- /dev/null
+++ b/src/writer/wgsl/generator_impl_unary_derivative_test.cc
@@ -0,0 +1,83 @@
+// Copyright 2020 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <memory>
+
+#include "gtest/gtest.h"
+#include "src/ast/identifier_expression.h"
+#include "src/ast/unary_derivative_expression.h"
+#include "src/writer/wgsl/generator_impl.h"
+
+namespace tint {
+namespace writer {
+namespace wgsl {
+namespace {
+
+struct UnaryDerivativeData {
+ const char* name;
+ ast::UnaryDerivative derivative;
+};
+inline std::ostream& operator<<(std::ostream& out, UnaryDerivativeData data) {
+ out << data.derivative;
+ return out;
+}
+using UnaryDerivativeTest = testing::TestWithParam<UnaryDerivativeData>;
+TEST_P(UnaryDerivativeTest, Emit_ModifierNone) {
+ auto params = GetParam();
+
+ auto expr = std::make_unique<ast::IdentifierExpression>("expr");
+
+ ast::UnaryDerivativeExpression derivative(
+ params.derivative, ast::DerivativeModifier::kNone, std::move(expr));
+
+ GeneratorImpl g;
+ ASSERT_TRUE(g.EmitExpression(&derivative)) << g.error();
+ EXPECT_EQ(g.result(), std::string(params.name) + "(expr)");
+}
+TEST_P(UnaryDerivativeTest, Emit_ModifierFine) {
+ auto params = GetParam();
+
+ auto expr = std::make_unique<ast::IdentifierExpression>("expr");
+
+ ast::UnaryDerivativeExpression derivative(
+ params.derivative, ast::DerivativeModifier::kFine, std::move(expr));
+
+ GeneratorImpl g;
+ ASSERT_TRUE(g.EmitExpression(&derivative)) << g.error();
+ EXPECT_EQ(g.result(), std::string(params.name) + "<fine>(expr)");
+}
+TEST_P(UnaryDerivativeTest, Emit_ModifierCoarse) {
+ auto params = GetParam();
+
+ auto expr = std::make_unique<ast::IdentifierExpression>("expr");
+
+ ast::UnaryDerivativeExpression derivative(
+ params.derivative, ast::DerivativeModifier::kCoarse, std::move(expr));
+
+ GeneratorImpl g;
+ ASSERT_TRUE(g.EmitExpression(&derivative)) << g.error();
+ EXPECT_EQ(g.result(), std::string(params.name) + "<coarse>(expr)");
+}
+INSTANTIATE_TEST_SUITE_P(
+ GeneratorImplTest,
+ UnaryDerivativeTest,
+ testing::Values(UnaryDerivativeData{"dpdx", ast::UnaryDerivative::kDpdx},
+ UnaryDerivativeData{"dpdy", ast::UnaryDerivative::kDpdy},
+ UnaryDerivativeData{"fwidth",
+ ast::UnaryDerivative::kFwidth}));
+
+} // namespace
+} // namespace wgsl
+} // namespace writer
+} // namespace tint
