[hlsl-writer] Add loop support.
This CL adds support for the LoopStatement emission in HLSL.
Bug: tint:7
Change-Id: Ie42b24abff3a69c9cbfe3d3c8ab6fb9b1823e61d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/25849
Reviewed-by: David Neto <dneto@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 8383657..8789413 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1054,6 +1054,7 @@
"src/writer/hlsl/generator_impl_discard_test.cc",
"src/writer/hlsl/generator_impl_identifier_test.cc",
"src/writer/hlsl/generator_impl_if_test.cc",
+ "src/writer/hlsl/generator_impl_loop_test.cc",
"src/writer/hlsl/generator_impl_member_accessor_test.cc",
"src/writer/hlsl/generator_impl_return_test.cc",
"src/writer/hlsl/generator_impl_switch_test.cc",
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 884f2e9..5a70f60 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -562,6 +562,7 @@
writer/hlsl/generator_impl_discard_test.cc
writer/hlsl/generator_impl_identifier_test.cc
writer/hlsl/generator_impl_if_test.cc
+ writer/hlsl/generator_impl_loop_test.cc
writer/hlsl/generator_impl_member_accessor_test.cc
writer/hlsl/generator_impl_return_test.cc
writer/hlsl/generator_impl_switch_test.cc
diff --git a/src/writer/hlsl/generator_impl.cc b/src/writer/hlsl/generator_impl.cc
index b0b03f8..fd77319 100644
--- a/src/writer/hlsl/generator_impl.cc
+++ b/src/writer/hlsl/generator_impl.cc
@@ -24,6 +24,7 @@
#include "src/ast/float_literal.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"
@@ -529,6 +530,60 @@
return true;
}
+bool GeneratorImpl::EmitLoop(ast::LoopStatement* stmt) {
+ loop_emission_counter_++;
+
+ std::string guard = namer_.NameFor("tint_hlsl_is_first_" +
+ std::to_string(loop_emission_counter_));
+
+ if (stmt->has_continuing()) {
+ make_indent();
+
+ // Continuing variables get their own scope.
+ out_ << "{" << std::endl;
+ increment_indent();
+
+ make_indent();
+ out_ << "bool " << guard << " = true;" << std::endl;
+ }
+
+ make_indent();
+ out_ << "for(;;) {" << std::endl;
+ increment_indent();
+
+ if (stmt->has_continuing()) {
+ make_indent();
+ out_ << "if (!" << guard << ") ";
+
+ if (!EmitBlockAndNewline(stmt->continuing())) {
+ return false;
+ }
+
+ make_indent();
+ out_ << guard << " = 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::EmitMemberAccessor(ast::MemberAccessorExpression* expr) {
if (!EmitExpression(expr->structure())) {
return false;
@@ -581,6 +636,9 @@
if (stmt->IsIf()) {
return EmitIf(stmt->AsIf());
}
+ if (stmt->IsLoop()) {
+ return EmitLoop(stmt->AsLoop());
+ }
if (stmt->IsReturn()) {
return EmitReturn(stmt->AsReturn());
}
diff --git a/src/writer/hlsl/generator_impl.h b/src/writer/hlsl/generator_impl.h
index e2efa9c..6c305a1 100644
--- a/src/writer/hlsl/generator_impl.h
+++ b/src/writer/hlsl/generator_impl.h
@@ -114,6 +114,10 @@
/// @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 emitted
+ bool EmitLoop(ast::LoopStatement* stmt);
/// Handles generating an identifier expression
/// @param expr the identifier expression
/// @returns true if the identifeir was emitted
@@ -171,6 +175,7 @@
ast::Module* module_ = nullptr;
std::string current_ep_name_;
bool generating_entry_point_ = false;
+ uint32_t loop_emission_counter_ = 0;
ScopeStack<ast::Variable*> global_variables_;
std::unordered_map<std::string, EntryPointData> ep_name_to_in_data_;
std::unordered_map<std::string, EntryPointData> ep_name_to_out_data_;
diff --git a/src/writer/hlsl/generator_impl_loop_test.cc b/src/writer/hlsl/generator_impl_loop_test.cc
new file mode 100644
index 0000000..1f9dabf
--- /dev/null
+++ b/src/writer/hlsl/generator_impl_loop_test.cc
@@ -0,0 +1,184 @@
+// 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/discard_statement.h"
+#include "src/ast/float_literal.h"
+#include "src/ast/identifier_expression.h"
+#include "src/ast/loop_statement.h"
+#include "src/ast/module.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/hlsl/generator_impl.h"
+
+namespace tint {
+namespace writer {
+namespace hlsl {
+namespace {
+
+using HlslGeneratorImplTest = testing::Test;
+
+TEST_F(HlslGeneratorImplTest, Emit_Loop) {
+ auto body = std::make_unique<ast::BlockStatement>();
+ body->append(std::make_unique<ast::DiscardStatement>());
+
+ ast::LoopStatement l(std::move(body), {});
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&l)) << g.error();
+ EXPECT_EQ(g.result(), R"( for(;;) {
+ discard;
+ }
+)");
+}
+
+TEST_F(HlslGeneratorImplTest, Emit_LoopWithContinuing) {
+ auto body = std::make_unique<ast::BlockStatement>();
+ body->append(std::make_unique<ast::DiscardStatement>());
+
+ auto continuing = std::make_unique<ast::BlockStatement>();
+ continuing->append(std::make_unique<ast::ReturnStatement>());
+
+ ast::LoopStatement l(std::move(body), std::move(continuing));
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&l)) << g.error();
+ EXPECT_EQ(g.result(), R"( {
+ bool tint_hlsl_is_first_1 = true;
+ for(;;) {
+ if (!tint_hlsl_is_first_1) {
+ return;
+ }
+ tint_hlsl_is_first_1 = false;
+
+ discard;
+ }
+ }
+)");
+}
+
+TEST_F(HlslGeneratorImplTest, Emit_LoopNestedWithContinuing) {
+ ast::type::F32Type f32;
+
+ auto body = std::make_unique<ast::BlockStatement>();
+ body->append(std::make_unique<ast::DiscardStatement>());
+
+ auto continuing = std::make_unique<ast::BlockStatement>();
+ continuing->append(std::make_unique<ast::ReturnStatement>());
+
+ auto inner = std::make_unique<ast::LoopStatement>(std::move(body),
+ std::move(continuing));
+
+ body = std::make_unique<ast::BlockStatement>();
+ body->append(std::move(inner));
+
+ auto lhs = std::make_unique<ast::IdentifierExpression>("lhs");
+ auto rhs = std::make_unique<ast::IdentifierExpression>("rhs");
+
+ continuing = std::make_unique<ast::BlockStatement>();
+ continuing->append(std::make_unique<ast::AssignmentStatement>(
+ std::move(lhs), std::move(rhs)));
+
+ ast::LoopStatement outer(std::move(body), std::move(continuing));
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&outer)) << g.error();
+ EXPECT_EQ(g.result(), R"( {
+ bool tint_hlsl_is_first_1 = true;
+ for(;;) {
+ if (!tint_hlsl_is_first_1) {
+ lhs = rhs;
+ }
+ tint_hlsl_is_first_1 = false;
+
+ {
+ bool tint_hlsl_is_first_2 = true;
+ for(;;) {
+ if (!tint_hlsl_is_first_2) {
+ return;
+ }
+ tint_hlsl_is_first_2 = false;
+
+ discard;
+ }
+ }
+ }
+ }
+)");
+}
+
+// TODO(dsinclair): Handle pulling declared variables up and out of the for() if
+// there is a continuing block.
+TEST_F(HlslGeneratorImplTest, 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)));
+
+ auto body = std::make_unique<ast::BlockStatement>();
+ body->append(std::make_unique<ast::VariableDeclStatement>(std::move(var)));
+ body->append(std::make_unique<ast::VariableDeclStatement>(
+ std::make_unique<ast::Variable>("other", ast::StorageClass::kFunction,
+ &f32)));
+
+ auto lhs = std::make_unique<ast::IdentifierExpression>("lhs");
+ auto rhs = std::make_unique<ast::IdentifierExpression>("rhs");
+
+ auto continuing = std::make_unique<ast::BlockStatement>();
+ continuing->append(std::make_unique<ast::AssignmentStatement>(
+ std::move(lhs), std::move(rhs)));
+
+ ast::LoopStatement outer(std::move(body), std::move(continuing));
+
+ ast::Module m;
+ GeneratorImpl g(&m);
+ g.increment_indent();
+
+ ASSERT_TRUE(g.EmitStatement(&outer)) << g.error();
+ EXPECT_EQ(g.result(), R"( {
+ float lhs;
+ bool tint_hlsl_is_first_1 = true;
+ for(;;) {
+ if (!tint_hlsl_is_first_1) {
+ lhs = rhs;
+ }
+ tint_hlsl_is_first_1 = false;
+
+ lhs = 2.40000010f;
+ float other;
+ }
+ }
+)");
+}
+
+} // namespace
+} // namespace hlsl
+} // namespace writer
+} // namespace tint
diff --git a/src/writer/msl/generator_impl_loop_test.cc b/src/writer/msl/generator_impl_loop_test.cc
index a44277f..1cf6609 100644
--- a/src/writer/msl/generator_impl_loop_test.cc
+++ b/src/writer/msl/generator_impl_loop_test.cc
@@ -132,7 +132,8 @@
)");
}
-// TODO(dsinclair): Make this work when we have variable declarations.
+// TODO(dsinclair): Handle pulling declared variables up and out of the for() if
+// there is a continuing block.
TEST_F(MslGeneratorImplTest, DISABLED_Emit_LoopWithVarUsedInContinuing) {
ast::type::F32Type f32;
@@ -170,7 +171,7 @@
}
tint_msl_is_first_1 = false;
- lhs = 2.4;
+ lhs = 2.40000010f;
float other;
}
}
