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-rw-r--r--src/shader_recompiler/frontend/ir/structured_control_flow.cpp742
1 files changed, 742 insertions, 0 deletions
diff --git a/src/shader_recompiler/frontend/ir/structured_control_flow.cpp b/src/shader_recompiler/frontend/ir/structured_control_flow.cpp
new file mode 100644
index 000000000..2e9ce2525
--- /dev/null
+++ b/src/shader_recompiler/frontend/ir/structured_control_flow.cpp
@@ -0,0 +1,742 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <memory>
+#include <ranges>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include <fmt/format.h>
+
+#include <boost/intrusive/list.hpp>
+
+#include "shader_recompiler/frontend/ir/basic_block.h"
+#include "shader_recompiler/frontend/ir/ir_emitter.h"
+#include "shader_recompiler/object_pool.h"
+
+namespace Shader::IR {
+namespace {
+struct Statement;
+
+// Use normal_link because we are not guaranteed to destroy the tree in order
+using ListBaseHook =
+ boost::intrusive::list_base_hook<boost::intrusive::link_mode<boost::intrusive::normal_link>>;
+
+using Tree = boost::intrusive::list<Statement,
+ // Allow using Statement without a definition
+ boost::intrusive::base_hook<ListBaseHook>,
+ // Avoid linear complexity on splice, size is never called
+ boost::intrusive::constant_time_size<false>>;
+using Node = Tree::iterator;
+using ConstNode = Tree::const_iterator;
+
+enum class StatementType {
+ Code,
+ Goto,
+ Label,
+ If,
+ Loop,
+ Break,
+ Return,
+ Function,
+ Identity,
+ Not,
+ Or,
+ SetVariable,
+ Variable,
+};
+
+bool HasChildren(StatementType type) {
+ switch (type) {
+ case StatementType::If:
+ case StatementType::Loop:
+ case StatementType::Function:
+ return true;
+ default:
+ return false;
+ }
+}
+
+struct Goto {};
+struct Label {};
+struct If {};
+struct Loop {};
+struct Break {};
+struct Return {};
+struct FunctionTag {};
+struct Identity {};
+struct Not {};
+struct Or {};
+struct SetVariable {};
+struct Variable {};
+
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 26495) // Always initialize a member variable, expected in Statement
+#endif
+struct Statement : ListBaseHook {
+ Statement(Block* code_, Statement* up_) : code{code_}, up{up_}, type{StatementType::Code} {}
+ Statement(Goto, Statement* cond_, Node label_, Statement* up_)
+ : label{label_}, cond{cond_}, up{up_}, type{StatementType::Goto} {}
+ Statement(Label, u32 id_, Statement* up_) : id{id_}, up{up_}, type{StatementType::Label} {}
+ Statement(If, Statement* cond_, Tree&& children_, Statement* up_)
+ : children{std::move(children_)}, cond{cond_}, up{up_}, type{StatementType::If} {}
+ Statement(Loop, Statement* cond_, Tree&& children_, Statement* up_)
+ : children{std::move(children_)}, cond{cond_}, up{up_}, type{StatementType::Loop} {}
+ Statement(Break, Statement* cond_, Statement* up_)
+ : cond{cond_}, up{up_}, type{StatementType::Break} {}
+ Statement(Return) : type{StatementType::Return} {}
+ Statement(FunctionTag) : children{}, type{StatementType::Function} {}
+ Statement(Identity, Condition cond_) : guest_cond{cond_}, type{StatementType::Identity} {}
+ Statement(Not, Statement* op_) : op{op_}, type{StatementType::Not} {}
+ Statement(Or, Statement* op_a_, Statement* op_b_)
+ : op_a{op_a_}, op_b{op_b_}, type{StatementType::Or} {}
+ Statement(SetVariable, u32 id_, Statement* op_, Statement* up_)
+ : op{op_}, id{id_}, up{up_}, type{StatementType::SetVariable} {}
+ Statement(Variable, u32 id_) : id{id_}, type{StatementType::Variable} {}
+
+ ~Statement() {
+ if (HasChildren(type)) {
+ std::destroy_at(&children);
+ }
+ }
+
+ union {
+ Block* code;
+ Node label;
+ Tree children;
+ Condition guest_cond;
+ Statement* op;
+ Statement* op_a;
+ };
+ union {
+ Statement* cond;
+ Statement* op_b;
+ u32 id;
+ };
+ Statement* up{};
+ StatementType type;
+};
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
+std::string DumpExpr(const Statement* stmt) {
+ switch (stmt->type) {
+ case StatementType::Identity:
+ return fmt::format("{}", stmt->guest_cond);
+ case StatementType::Not:
+ return fmt::format("!{}", DumpExpr(stmt->op));
+ case StatementType::Or:
+ return fmt::format("{} || {}", DumpExpr(stmt->op_a), DumpExpr(stmt->op_b));
+ case StatementType::Variable:
+ return fmt::format("goto_L{}", stmt->id);
+ default:
+ return "<invalid type>";
+ }
+}
+
+std::string DumpTree(const Tree& tree, u32 indentation = 0) {
+ std::string ret;
+ std::string indent(indentation, ' ');
+ for (auto stmt = tree.begin(); stmt != tree.end(); ++stmt) {
+ switch (stmt->type) {
+ case StatementType::Code:
+ ret += fmt::format("{} Block {:04x};\n", indent, stmt->code->LocationBegin());
+ break;
+ case StatementType::Goto:
+ ret += fmt::format("{} if ({}) goto L{};\n", indent, DumpExpr(stmt->cond),
+ stmt->label->id);
+ break;
+ case StatementType::Label:
+ ret += fmt::format("{}L{}:\n", indent, stmt->id);
+ break;
+ case StatementType::If:
+ ret += fmt::format("{} if ({}) {{\n", indent, DumpExpr(stmt->cond));
+ ret += DumpTree(stmt->children, indentation + 4);
+ ret += fmt::format("{} }}\n", indent);
+ break;
+ case StatementType::Loop:
+ ret += fmt::format("{} do {{\n", indent);
+ ret += DumpTree(stmt->children, indentation + 4);
+ ret += fmt::format("{} }} while ({});\n", indent, DumpExpr(stmt->cond));
+ break;
+ case StatementType::Break:
+ ret += fmt::format("{} if ({}) break;\n", indent, DumpExpr(stmt->cond));
+ break;
+ case StatementType::Return:
+ ret += fmt::format("{} return;\n", indent);
+ break;
+ case StatementType::SetVariable:
+ ret += fmt::format("{} goto_L{} = {};\n", indent, stmt->id, DumpExpr(stmt->op));
+ break;
+ case StatementType::Function:
+ case StatementType::Identity:
+ case StatementType::Not:
+ case StatementType::Or:
+ case StatementType::Variable:
+ throw LogicError("Statement can't be printed");
+ }
+ }
+ return ret;
+}
+
+bool HasNode(const Tree& tree, ConstNode stmt) {
+ const auto end{tree.end()};
+ for (auto it = tree.begin(); it != end; ++it) {
+ if (it == stmt || (HasChildren(it->type) && HasNode(it->children, stmt))) {
+ return true;
+ }
+ }
+ return false;
+}
+
+Node FindStatementWithLabel(Tree& tree, ConstNode goto_stmt) {
+ const ConstNode label_stmt{goto_stmt->label};
+ const ConstNode end{tree.end()};
+ for (auto it = tree.begin(); it != end; ++it) {
+ if (it == label_stmt || (HasChildren(it->type) && HasNode(it->children, label_stmt))) {
+ return it;
+ }
+ }
+ throw LogicError("Lift label not in tree");
+}
+
+void SanitizeNoBreaks(const Tree& tree) {
+ if (std::ranges::find(tree, StatementType::Break, &Statement::type) != tree.end()) {
+ throw NotImplementedException("Capturing statement with break nodes");
+ }
+}
+
+size_t Level(Node stmt) {
+ size_t level{0};
+ Statement* node{stmt->up};
+ while (node) {
+ ++level;
+ node = node->up;
+ }
+ return level;
+}
+
+bool IsDirectlyRelated(Node goto_stmt, Node label_stmt) {
+ const size_t goto_level{Level(goto_stmt)};
+ const size_t label_level{Level(label_stmt)};
+ size_t min_level;
+ size_t max_level;
+ Node min;
+ Node max;
+ if (label_level < goto_level) {
+ min_level = label_level;
+ max_level = goto_level;
+ min = label_stmt;
+ max = goto_stmt;
+ } else { // goto_level < label_level
+ min_level = goto_level;
+ max_level = label_level;
+ min = goto_stmt;
+ max = label_stmt;
+ }
+ while (max_level > min_level) {
+ --max_level;
+ max = max->up;
+ }
+ return min->up == max->up;
+}
+
+bool IsIndirectlyRelated(Node goto_stmt, Node label_stmt) {
+ return goto_stmt->up != label_stmt->up && !IsDirectlyRelated(goto_stmt, label_stmt);
+}
+
+bool SearchNode(const Tree& tree, ConstNode stmt, size_t& offset) {
+ ++offset;
+
+ const auto end = tree.end();
+ for (ConstNode it = tree.begin(); it != end; ++it) {
+ ++offset;
+ if (stmt == it) {
+ return true;
+ }
+ if (HasChildren(it->type) && SearchNode(it->children, stmt, offset)) {
+ return true;
+ }
+ }
+ return false;
+}
+
+class GotoPass {
+public:
+ explicit GotoPass(std::span<Block* const> blocks, ObjectPool<Statement, 64>& stmt_pool)
+ : pool{stmt_pool} {
+ std::vector gotos{BuildUnorderedTreeGetGotos(blocks)};
+ fmt::print(stdout, "BEFORE\n{}\n", DumpTree(root_stmt.children));
+ for (const Node& goto_stmt : gotos | std::views::reverse) {
+ RemoveGoto(goto_stmt);
+ }
+ fmt::print(stdout, "AFTER\n{}\n", DumpTree(root_stmt.children));
+ }
+
+ Statement& RootStatement() noexcept {
+ return root_stmt;
+ }
+
+private:
+ void RemoveGoto(Node goto_stmt) {
+ // Force goto_stmt and label_stmt to be directly related
+ const Node label_stmt{goto_stmt->label};
+ if (IsIndirectlyRelated(goto_stmt, label_stmt)) {
+ // Move goto_stmt out using outward-movement transformation until it becomes
+ // directly related to label_stmt
+ while (!IsDirectlyRelated(goto_stmt, label_stmt)) {
+ goto_stmt = MoveOutward(goto_stmt);
+ }
+ }
+ // Force goto_stmt and label_stmt to be siblings
+ if (IsDirectlyRelated(goto_stmt, label_stmt)) {
+ const size_t label_level{Level(label_stmt)};
+ size_t goto_level{Level(goto_stmt)};
+ if (goto_level > label_level) {
+ // Move goto_stmt out of its level using outward-movement transformations
+ while (goto_level > label_level) {
+ goto_stmt = MoveOutward(goto_stmt);
+ --goto_level;
+ }
+ } else { // Level(goto_stmt) < Level(label_stmt)
+ if (Offset(goto_stmt) > Offset(label_stmt)) {
+ // Lift goto_stmt to above stmt containing label_stmt using goto-lifting
+ // transformations
+ goto_stmt = Lift(goto_stmt);
+ }
+ // Move goto_stmt into label_stmt's level using inward-movement transformation
+ while (goto_level < label_level) {
+ goto_stmt = MoveInward(goto_stmt);
+ ++goto_level;
+ }
+ }
+ }
+ // TODO: Remove this
+ Node it{goto_stmt};
+ bool sibling{false};
+ do {
+ sibling |= it == label_stmt;
+ --it;
+ } while (it != goto_stmt->up->children.begin());
+ while (it != goto_stmt->up->children.end()) {
+ sibling |= it == label_stmt;
+ ++it;
+ }
+ if (!sibling) {
+ throw LogicError("Not siblings");
+ }
+
+ // goto_stmt and label_stmt are guaranteed to be siblings, eliminate
+ if (std::next(goto_stmt) == label_stmt) {
+ // Simply eliminate the goto if the label is next to it
+ goto_stmt->up->children.erase(goto_stmt);
+ } else if (Offset(goto_stmt) < Offset(label_stmt)) {
+ // Eliminate goto_stmt with a conditional
+ EliminateAsConditional(goto_stmt, label_stmt);
+ } else {
+ // Eliminate goto_stmt with a loop
+ EliminateAsLoop(goto_stmt, label_stmt);
+ }
+ }
+
+ std::vector<Node> BuildUnorderedTreeGetGotos(std::span<Block* const> blocks) {
+ // Assume all blocks have two branches
+ std::vector<Node> gotos;
+ gotos.reserve(blocks.size() * 2);
+
+ const std::unordered_map labels_map{BuildLabels(blocks)};
+ Tree& root{root_stmt.children};
+ auto insert_point{root.begin()};
+ for (Block* const block : blocks) {
+ ++insert_point; // Skip label
+ ++insert_point; // Skip set variable
+ root.insert(insert_point, *pool.Create(block, &root_stmt));
+
+ if (block->IsTerminationBlock()) {
+ root.insert(insert_point, *pool.Create(Return{}));
+ continue;
+ }
+ const Condition cond{block->BranchCondition()};
+ Statement* const true_cond{pool.Create(Identity{}, Condition{true})};
+ if (cond == Condition{true} || cond == Condition{false}) {
+ const bool is_true{cond == Condition{true}};
+ const Block* const branch{is_true ? block->TrueBranch() : block->FalseBranch()};
+ const Node label{labels_map.at(branch)};
+ Statement* const goto_stmt{pool.Create(Goto{}, true_cond, label, &root_stmt)};
+ gotos.push_back(root.insert(insert_point, *goto_stmt));
+ } else {
+ Statement* const ident_cond{pool.Create(Identity{}, cond)};
+ const Node true_label{labels_map.at(block->TrueBranch())};
+ const Node false_label{labels_map.at(block->FalseBranch())};
+ Statement* goto_true{pool.Create(Goto{}, ident_cond, true_label, &root_stmt)};
+ Statement* goto_false{pool.Create(Goto{}, true_cond, false_label, &root_stmt)};
+ gotos.push_back(root.insert(insert_point, *goto_true));
+ gotos.push_back(root.insert(insert_point, *goto_false));
+ }
+ }
+ return gotos;
+ }
+
+ std::unordered_map<const Block*, Node> BuildLabels(std::span<Block* const> blocks) {
+ // TODO: Consider storing labels intrusively inside the block
+ std::unordered_map<const Block*, Node> labels_map;
+ Tree& root{root_stmt.children};
+ u32 label_id{0};
+ for (const Block* const block : blocks) {
+ Statement* const label{pool.Create(Label{}, label_id, &root_stmt)};
+ labels_map.emplace(block, root.insert(root.end(), *label));
+ Statement* const false_stmt{pool.Create(Identity{}, Condition{false})};
+ root.push_back(*pool.Create(SetVariable{}, label_id, false_stmt, &root_stmt));
+ ++label_id;
+ }
+ return labels_map;
+ }
+
+ void UpdateTreeUp(Statement* tree) {
+ for (Statement& stmt : tree->children) {
+ stmt.up = tree;
+ }
+ }
+
+ void EliminateAsConditional(Node goto_stmt, Node label_stmt) {
+ Tree& body{goto_stmt->up->children};
+ Tree if_body;
+ if_body.splice(if_body.begin(), body, std::next(goto_stmt), label_stmt);
+ Statement* const cond{pool.Create(Not{}, goto_stmt->cond)};
+ Statement* const if_stmt{pool.Create(If{}, cond, std::move(if_body), goto_stmt->up)};
+ UpdateTreeUp(if_stmt);
+ body.insert(goto_stmt, *if_stmt);
+ body.erase(goto_stmt);
+ }
+
+ void EliminateAsLoop(Node goto_stmt, Node label_stmt) {
+ Tree& body{goto_stmt->up->children};
+ Tree loop_body;
+ loop_body.splice(loop_body.begin(), body, label_stmt, goto_stmt);
+ Statement* const cond{goto_stmt->cond};
+ Statement* const loop{pool.Create(Loop{}, cond, std::move(loop_body), goto_stmt->up)};
+ UpdateTreeUp(loop);
+ body.insert(goto_stmt, *loop);
+ body.erase(goto_stmt);
+ }
+
+ [[nodiscard]] Node MoveOutward(Node goto_stmt) {
+ switch (goto_stmt->up->type) {
+ case StatementType::If:
+ return MoveOutwardIf(goto_stmt);
+ case StatementType::Loop:
+ return MoveOutwardLoop(goto_stmt);
+ default:
+ throw LogicError("Invalid outward movement");
+ }
+ }
+
+ [[nodiscard]] Node MoveInward(Node goto_stmt) {
+ Statement* const parent{goto_stmt->up};
+ Tree& body{parent->children};
+ const Node label_nested_stmt{FindStatementWithLabel(body, goto_stmt)};
+ const Node label{goto_stmt->label};
+ const u32 label_id{label->id};
+
+ Statement* const goto_cond{goto_stmt->cond};
+ Statement* const set_var{pool.Create(SetVariable{}, label_id, goto_cond, parent)};
+ body.insert(goto_stmt, *set_var);
+
+ Tree if_body;
+ if_body.splice(if_body.begin(), body, std::next(goto_stmt), label_nested_stmt);
+ Statement* const variable{pool.Create(Variable{}, label_id)};
+ Statement* const neg_var{pool.Create(Not{}, variable)};
+ if (!if_body.empty()) {
+ Statement* const if_stmt{pool.Create(If{}, neg_var, std::move(if_body), parent)};
+ UpdateTreeUp(if_stmt);
+ body.insert(goto_stmt, *if_stmt);
+ }
+ body.erase(goto_stmt);
+
+ // Update nested if condition
+ switch (label_nested_stmt->type) {
+ case StatementType::If:
+ label_nested_stmt->cond = pool.Create(Or{}, neg_var, label_nested_stmt->cond);
+ break;
+ case StatementType::Loop:
+ break;
+ default:
+ throw LogicError("Invalid inward movement");
+ }
+ Tree& nested_tree{label_nested_stmt->children};
+ Statement* const new_goto{pool.Create(Goto{}, variable, label, &*label_nested_stmt)};
+ return nested_tree.insert(nested_tree.begin(), *new_goto);
+ }
+
+ [[nodiscard]] Node Lift(Node goto_stmt) {
+ Statement* const parent{goto_stmt->up};
+ Tree& body{parent->children};
+ const Node label{goto_stmt->label};
+ const u32 label_id{label->id};
+ const Node label_nested_stmt{FindStatementWithLabel(body, goto_stmt)};
+ const auto type{label_nested_stmt->type};
+
+ Tree loop_body;
+ loop_body.splice(loop_body.begin(), body, label_nested_stmt, goto_stmt);
+ SanitizeNoBreaks(loop_body);
+ Statement* const variable{pool.Create(Variable{}, label_id)};
+ Statement* const loop_stmt{pool.Create(Loop{}, variable, std::move(loop_body), parent)};
+ UpdateTreeUp(loop_stmt);
+ const Node loop_node{body.insert(goto_stmt, *loop_stmt)};
+
+ Statement* const new_goto{pool.Create(Goto{}, variable, label, loop_stmt)};
+ loop_stmt->children.push_front(*new_goto);
+ const Node new_goto_node{loop_stmt->children.begin()};
+
+ Statement* const set_var{pool.Create(SetVariable{}, label_id, goto_stmt->cond, loop_stmt)};
+ loop_stmt->children.push_back(*set_var);
+
+ body.erase(goto_stmt);
+ return new_goto_node;
+ }
+
+ Node MoveOutwardIf(Node goto_stmt) {
+ const Node parent{Tree::s_iterator_to(*goto_stmt->up)};
+ Tree& body{parent->children};
+ const u32 label_id{goto_stmt->label->id};
+ Statement* const goto_cond{goto_stmt->cond};
+ Statement* const set_goto_var{pool.Create(SetVariable{}, label_id, goto_cond, &*parent)};
+ body.insert(goto_stmt, *set_goto_var);
+
+ Tree if_body;
+ if_body.splice(if_body.begin(), body, std::next(goto_stmt), body.end());
+ if_body.pop_front();
+ Statement* const cond{pool.Create(Variable{}, label_id)};
+ Statement* const neg_cond{pool.Create(Not{}, cond)};
+ Statement* const if_stmt{pool.Create(If{}, neg_cond, std::move(if_body), &*parent)};
+ UpdateTreeUp(if_stmt);
+ body.insert(goto_stmt, *if_stmt);
+
+ body.erase(goto_stmt);
+
+ Statement* const new_cond{pool.Create(Variable{}, label_id)};
+ Statement* const new_goto{pool.Create(Goto{}, new_cond, goto_stmt->label, parent->up)};
+ Tree& parent_tree{parent->up->children};
+ return parent_tree.insert(std::next(parent), *new_goto);
+ }
+
+ Node MoveOutwardLoop(Node goto_stmt) {
+ Statement* const parent{goto_stmt->up};
+ Tree& body{parent->children};
+ const u32 label_id{goto_stmt->label->id};
+ Statement* const goto_cond{goto_stmt->cond};
+ Statement* const set_goto_var{pool.Create(SetVariable{}, label_id, goto_cond, parent)};
+ Statement* const cond{pool.Create(Variable{}, label_id)};
+ Statement* const break_stmt{pool.Create(Break{}, cond, parent)};
+ body.insert(goto_stmt, *set_goto_var);
+ body.insert(goto_stmt, *break_stmt);
+ body.erase(goto_stmt);
+
+ const Node loop{Tree::s_iterator_to(*goto_stmt->up)};
+ Statement* const new_goto_cond{pool.Create(Variable{}, label_id)};
+ Statement* const new_goto{pool.Create(Goto{}, new_goto_cond, goto_stmt->label, loop->up)};
+ Tree& parent_tree{loop->up->children};
+ return parent_tree.insert(std::next(loop), *new_goto);
+ }
+
+ size_t Offset(ConstNode stmt) const {
+ size_t offset{0};
+ if (!SearchNode(root_stmt.children, stmt, offset)) {
+ fmt::print(stdout, "{}\n", DumpTree(root_stmt.children));
+ throw LogicError("Node not found in tree");
+ }
+ return offset;
+ }
+
+ ObjectPool<Statement, 64>& pool;
+ Statement root_stmt{FunctionTag{}};
+};
+
+Block* TryFindForwardBlock(const Statement& stmt) {
+ const Tree& tree{stmt.up->children};
+ const ConstNode end{tree.cend()};
+ ConstNode forward_node{std::next(Tree::s_iterator_to(stmt))};
+ while (forward_node != end && !HasChildren(forward_node->type)) {
+ if (forward_node->type == StatementType::Code) {
+ return forward_node->code;
+ }
+ ++forward_node;
+ }
+ return nullptr;
+}
+
+[[nodiscard]] U1 VisitExpr(IREmitter& ir, const Statement& stmt) {
+ switch (stmt.type) {
+ case StatementType::Identity:
+ return ir.Condition(stmt.guest_cond);
+ case StatementType::Not:
+ return ir.LogicalNot(U1{VisitExpr(ir, *stmt.op)});
+ case StatementType::Or:
+ return ir.LogicalOr(VisitExpr(ir, *stmt.op_a), VisitExpr(ir, *stmt.op_b));
+ case StatementType::Variable:
+ return ir.GetGotoVariable(stmt.id);
+ default:
+ throw NotImplementedException("Statement type {}", stmt.type);
+ }
+}
+
+class TranslatePass {
+public:
+ TranslatePass(ObjectPool<Inst>& inst_pool_, ObjectPool<Block>& block_pool_,
+ ObjectPool<Statement, 64>& stmt_pool_, Statement& root_stmt,
+ const std::function<void(IR::Block*)>& func_, BlockList& block_list_)
+ : stmt_pool{stmt_pool_}, inst_pool{inst_pool_}, block_pool{block_pool_}, func{func_},
+ block_list{block_list_} {
+ Visit(root_stmt, nullptr, nullptr);
+ }
+
+private:
+ void Visit(Statement& parent, Block* continue_block, Block* break_block) {
+ Tree& tree{parent.children};
+ Block* current_block{nullptr};
+
+ for (auto it = tree.begin(); it != tree.end(); ++it) {
+ Statement& stmt{*it};
+ switch (stmt.type) {
+ case StatementType::Label:
+ // Labels can be ignored
+ break;
+ case StatementType::Code: {
+ if (current_block && current_block != stmt.code) {
+ IREmitter ir{*current_block};
+ ir.Branch(stmt.code);
+ }
+ current_block = stmt.code;
+ func(stmt.code);
+ block_list.push_back(stmt.code);
+ break;
+ }
+ case StatementType::SetVariable: {
+ if (!current_block) {
+ current_block = MergeBlock(parent, stmt);
+ }
+ IREmitter ir{*current_block};
+ ir.SetGotoVariable(stmt.id, VisitExpr(ir, *stmt.op));
+ break;
+ }
+ case StatementType::If: {
+ if (!current_block) {
+ current_block = block_pool.Create(inst_pool);
+ block_list.push_back(current_block);
+ }
+ Block* const merge_block{MergeBlock(parent, stmt)};
+
+ // Visit children
+ const size_t first_block_index{block_list.size()};
+ Visit(stmt, merge_block, break_block);
+
+ // Implement if header block
+ Block* const first_if_block{block_list.at(first_block_index)};
+ IREmitter ir{*current_block};
+ const U1 cond{VisitExpr(ir, *stmt.cond)};
+ ir.SelectionMerge(merge_block);
+ ir.BranchConditional(cond, first_if_block, merge_block);
+
+ current_block = merge_block;
+ break;
+ }
+ case StatementType::Loop: {
+ Block* const loop_header_block{block_pool.Create(inst_pool)};
+ if (current_block) {
+ IREmitter{*current_block}.Branch(loop_header_block);
+ }
+ block_list.push_back(loop_header_block);
+
+ Block* const new_continue_block{block_pool.Create(inst_pool)};
+ Block* const merge_block{MergeBlock(parent, stmt)};
+
+ // Visit children
+ const size_t first_block_index{block_list.size()};
+ Visit(stmt, new_continue_block, merge_block);
+
+ // The continue block is located at the end of the loop
+ block_list.push_back(new_continue_block);
+
+ // Implement loop header block
+ Block* const first_loop_block{block_list.at(first_block_index)};
+ IREmitter ir{*loop_header_block};
+ ir.LoopMerge(merge_block, new_continue_block);
+ ir.Branch(first_loop_block);
+
+ // Implement continue block
+ IREmitter continue_ir{*new_continue_block};
+ const U1 continue_cond{VisitExpr(continue_ir, *stmt.cond)};
+ continue_ir.BranchConditional(continue_cond, ir.block, merge_block);
+
+ current_block = merge_block;
+ break;
+ }
+ case StatementType::Break: {
+ if (!current_block) {
+ current_block = block_pool.Create(inst_pool);
+ block_list.push_back(current_block);
+ }
+ Block* const skip_block{MergeBlock(parent, stmt)};
+
+ IREmitter ir{*current_block};
+ ir.BranchConditional(VisitExpr(ir, *stmt.cond), break_block, skip_block);
+
+ current_block = skip_block;
+ break;
+ }
+ case StatementType::Return: {
+ if (!current_block) {
+ current_block = block_pool.Create(inst_pool);
+ block_list.push_back(current_block);
+ }
+ IREmitter{*current_block}.Return();
+ current_block = nullptr;
+ break;
+ }
+ default:
+ throw NotImplementedException("Statement type {}", stmt.type);
+ }
+ }
+ if (current_block && continue_block) {
+ IREmitter ir{*current_block};
+ ir.Branch(continue_block);
+ }
+ }
+
+ Block* MergeBlock(Statement& parent, Statement& stmt) {
+ if (Block* const block{TryFindForwardBlock(stmt)}) {
+ return block;
+ }
+ // Create a merge block we can visit later
+ Block* const block{block_pool.Create(inst_pool)};
+ Statement* const merge_stmt{stmt_pool.Create(block, &parent)};
+ parent.children.insert(std::next(Tree::s_iterator_to(stmt)), *merge_stmt);
+ return block;
+ }
+
+ ObjectPool<Statement, 64>& stmt_pool;
+ ObjectPool<Inst>& inst_pool;
+ ObjectPool<Block>& block_pool;
+ const std::function<void(IR::Block*)>& func;
+ BlockList& block_list;
+};
+} // Anonymous namespace
+
+BlockList VisitAST(ObjectPool<Inst>& inst_pool, ObjectPool<Block>& block_pool,
+ std::span<Block* const> unordered_blocks,
+ const std::function<void(Block*)>& func) {
+ ObjectPool<Statement, 64> stmt_pool;
+ GotoPass goto_pass{unordered_blocks, stmt_pool};
+ BlockList block_list;
+ TranslatePass translate_pass{inst_pool, block_pool, stmt_pool, goto_pass.RootStatement(),
+ func, block_list};
+ return block_list;
+}
+
+} // namespace Shader::IR