[msl-writer] Emit loop statements.
This CL adds the code to convert a loop/continuing statement into MSL.
Bug: tint:8
Change-Id: I9fa595908c6d834d9543b583c8baf8c19f8cae6c
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/24122
Reviewed-by: David Neto <dneto@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 4643fca..7c13039 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -897,6 +897,7 @@
"src/writer/msl/generator_impl_identifier_test.cc",
"src/writer/msl/generator_impl_if_test.cc",
"src/writer/msl/generator_impl_kill_test.cc",
+ "src/writer/msl/generator_impl_loop_test.cc",
"src/writer/msl/generator_impl_member_accessor_test.cc",
"src/writer/msl/generator_impl_return_test.cc",
"src/writer/msl/generator_impl_test.cc",
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 5a64fba..82f26d0 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -505,6 +505,7 @@
writer/msl/generator_impl_identifier_test.cc
writer/msl/generator_impl_if_test.cc
writer/msl/generator_impl_kill_test.cc
+ writer/msl/generator_impl_loop_test.cc
writer/msl/generator_impl_member_accessor_test.cc
writer/msl/generator_impl_return_test.cc
writer/msl/generator_impl_test.cc
diff --git a/src/writer/msl/generator_impl.cc b/src/writer/msl/generator_impl.cc
index 04eba00..466688e 100644
--- a/src/writer/msl/generator_impl.cc
+++ b/src/writer/msl/generator_impl.cc
@@ -27,6 +27,7 @@
#include "src/ast/function.h"
#include "src/ast/identifier_expression.h"
#include "src/ast/if_statement.h"
+#include "src/ast/loop_statement.h"
#include "src/ast/member_accessor_expression.h"
#include "src/ast/return_statement.h"
#include "src/ast/sint_literal.h"
@@ -407,6 +408,59 @@
return true;
}
+bool GeneratorImpl::EmitLoop(ast::LoopStatement* stmt) {
+ loop_emission_counter_++;
+
+ if (stmt->has_continuing()) {
+ make_indent();
+
+ // Continuing variables get their own scope.
+ out_ << "{" << std::endl;
+ increment_indent();
+
+ make_indent();
+ out_ << "bool tint_msl_is_first_" << loop_emission_counter_ << " = true;"
+ << std::endl;
+ }
+
+ make_indent();
+ out_ << "for(;;) {" << std::endl;
+ increment_indent();
+
+ if (stmt->has_continuing()) {
+ make_indent();
+ out_ << "if (!tint_msl_is_first_" << loop_emission_counter_ << ")";
+
+ if (!EmitStatementBlockAndNewline(stmt->continuing())) {
+ return false;
+ }
+
+ make_indent();
+ out_ << "tint_msl_is_first_" << loop_emission_counter_ << " = false;"
+ << std::endl;
+ out_ << std::endl;
+ }
+
+ for (const auto& s : stmt->body()) {
+ if (!EmitStatement(s.get())) {
+ return false;
+ }
+ }
+
+ decrement_indent();
+ make_indent();
+ out_ << "}" << std::endl;
+
+ // Close the scope for any continuing variables.
+ if (stmt->has_continuing()) {
+ decrement_indent();
+ make_indent();
+ out_ << "}" << std::endl;
+ }
+
+ return true;
+}
+
bool GeneratorImpl::EmitKill(ast::KillStatement*) {
make_indent();
// TODO(dsinclair): Verify this is correct when the kill semantics are defined
@@ -519,6 +573,9 @@
if (stmt->IsKill()) {
return EmitKill(stmt->AsKill());
}
+ if (stmt->IsLoop()) {
+ return EmitLoop(stmt->AsLoop());
+ }
if (stmt->IsReturn()) {
return EmitReturn(stmt->AsReturn());
}
diff --git a/src/writer/msl/generator_impl.h b/src/writer/msl/generator_impl.h
index 77391b5..d74ff04 100644
--- a/src/writer/msl/generator_impl.h
+++ b/src/writer/msl/generator_impl.h
@@ -104,6 +104,10 @@
/// @param lit the literal to emit
/// @returns true if the literal was successfully emitted
bool EmitLiteral(ast::Literal* lit);
+ /// Handles a loop statement
+ /// @param stmt the statement to emit
+ /// @returns true if the statement was emtited
+ bool EmitLoop(ast::LoopStatement* stmt);
/// Handles a member accessor expression
/// @param expr the member accessor expression
/// @returns true if the member accessor was emitted
@@ -147,6 +151,7 @@
private:
const ast::Module* module_ = nullptr;
+ uint32_t loop_emission_counter_ = 0;
};
} // namespace msl
diff --git a/src/writer/msl/generator_impl_loop_test.cc b/src/writer/msl/generator_impl_loop_test.cc
new file mode 100644
index 0000000..cbbbfb1
--- /dev/null
+++ b/src/writer/msl/generator_impl_loop_test.cc
@@ -0,0 +1,173 @@
+// 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/assignment_statement.h"
+#include "src/ast/float_literal.h"
+#include "src/ast/identifier_expression.h"
+#include "src/ast/kill_statement.h"
+#include "src/ast/loop_statement.h"
+#include "src/ast/return_statement.h"
+#include "src/ast/type/f32_type.h"
+#include "src/ast/variable.h"
+#include "src/ast/variable_decl_statement.h"
+#include "src/writer/msl/generator_impl.h"
+
+namespace tint {
+namespace writer {
+namespace msl {
+namespace {
+
+using MslGeneratorImplTest = testing::Test;
+
+TEST_F(MslGeneratorImplTest, Emit_Loop) {
+ ast::StatementList body;
+ body.push_back(std::make_unique<ast::KillStatement>());
+
+ ast::LoopStatement l(std::move(body), {});
+
+ GeneratorImpl g;
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&l)) << g.error();
+ EXPECT_EQ(g.result(), R"( for(;;) {
+ discard_fragment();
+ }
+)");
+}
+
+TEST_F(MslGeneratorImplTest, Emit_LoopWithContinuing) {
+ ast::StatementList body;
+ body.push_back(std::make_unique<ast::KillStatement>());
+
+ ast::StatementList continuing;
+ continuing.push_back(std::make_unique<ast::ReturnStatement>());
+
+ ast::LoopStatement l(std::move(body), std::move(continuing));
+
+ GeneratorImpl g;
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&l)) << g.error();
+ EXPECT_EQ(g.result(), R"( {
+ bool tint_msl_is_first_1 = true;
+ for(;;) {
+ if (!tint_msl_is_first_1) {
+ return;
+ }
+ tint_msl_is_first_1 = false;
+
+ discard_fragment();
+ }
+ }
+)");
+}
+
+TEST_F(MslGeneratorImplTest, Emit_LoopNestedWithContinuing) {
+ ast::type::F32Type f32;
+
+ ast::StatementList body;
+ body.push_back(std::make_unique<ast::KillStatement>());
+
+ ast::StatementList continuing;
+ continuing.push_back(std::make_unique<ast::ReturnStatement>());
+
+ auto inner = std::make_unique<ast::LoopStatement>(std::move(body),
+ std::move(continuing));
+
+ body.push_back(std::move(inner));
+
+ auto lhs = std::make_unique<ast::IdentifierExpression>("lhs");
+ auto rhs = std::make_unique<ast::IdentifierExpression>("rhs");
+ continuing.push_back(std::make_unique<ast::AssignmentStatement>(
+ std::move(lhs), std::move(rhs)));
+
+ ast::LoopStatement outer(std::move(body), std::move(continuing));
+
+ GeneratorImpl g;
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&outer)) << g.error();
+ EXPECT_EQ(g.result(), R"( {
+ bool tint_msl_is_first_1 = true;
+ for(;;) {
+ if (!tint_msl_is_first_1) {
+ lhs = rhs;
+ }
+ tint_msl_is_first_1 = false;
+
+ {
+ bool tint_msl_is_first_2 = true;
+ for(;;) {
+ if (!tint_msl_is_first_2) {
+ return;
+ }
+ tint_msl_is_first_2 = false;
+
+ discard_fragment();
+ }
+ }
+ }
+ }
+)");
+}
+
+// TODO(dsinclair): Make this work when we have variable declarations.
+TEST_F(MslGeneratorImplTest, DISABLED_Emit_LoopWithVarUsedInContinuing) {
+ ast::type::F32Type f32;
+
+ auto var = std::make_unique<ast::Variable>(
+ "lhs", ast::StorageClass::kFunction, &f32);
+ var->set_constructor(std::make_unique<ast::ScalarConstructorExpression>(
+ std::make_unique<ast::FloatLiteral>(&f32, 2.4)));
+
+ ast::StatementList body;
+ body.push_back(std::make_unique<ast::VariableDeclStatement>(std::move(var)));
+ body.push_back(std::make_unique<ast::VariableDeclStatement>(
+ std::make_unique<ast::Variable>("other", ast::StorageClass::kFunction,
+ &f32)));
+
+ ast::StatementList continuing;
+ auto lhs = std::make_unique<ast::IdentifierExpression>("lhs");
+ auto rhs = std::make_unique<ast::IdentifierExpression>("rhs");
+ continuing.push_back(std::make_unique<ast::AssignmentStatement>(
+ std::move(lhs), std::move(rhs)));
+
+ ast::LoopStatement outer(std::move(body), std::move(continuing));
+
+ GeneratorImpl g;
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&outer)) << g.error();
+ EXPECT_EQ(g.result(), R"( {
+ float lhs;
+ bool tint_msl_is_first_1 = true;
+ for(;;) {
+ if (!tint_msl_is_first_1) {
+ lhs = rhs;
+ }
+ tint_msl_is_first_1 = false;
+
+ lhs = 2.4;
+ float other;
+ }
+ }
+)");
+}
+} // namespace
+} // namespace msl
+} // namespace writer
+} // namespace tint
