shader_ir: Add basic goto elimination

This commit is contained in:
Fernando Sahmkow 2019-06-27 18:57:47 -04:00 committed by FernandoS27
parent c17953978b
commit 4fde66e609
2 changed files with 486 additions and 40 deletions

View file

@ -11,6 +11,147 @@
namespace VideoCommon::Shader { namespace VideoCommon::Shader {
ASTZipper::ASTZipper() = default;
ASTZipper::ASTZipper(ASTNode new_first) : first{}, last{} {
first = new_first;
last = new_first;
ASTNode current = first;
while (current) {
current->manager = this;
last = current;
current = current->next;
}
}
void ASTZipper::PushBack(ASTNode new_node) {
new_node->previous = last;
if (last) {
last->next = new_node;
}
new_node->next.reset();
last = new_node;
if (!first) {
first = new_node;
}
new_node->manager = this;
}
void ASTZipper::PushFront(ASTNode new_node) {
new_node->previous.reset();
new_node->next = first;
if (first) {
first->previous = first;
}
first = new_node;
if (!last) {
last = new_node;
}
new_node->manager = this;
}
void ASTZipper::InsertAfter(ASTNode new_node, ASTNode at_node) {
if (!at_node) {
PushFront(new_node);
return;
}
new_node->previous = at_node;
if (at_node == last) {
last = new_node;
}
new_node->next = at_node->next;
at_node->next = new_node;
new_node->manager = this;
}
void ASTZipper::SetParent(ASTNode new_parent) {
ASTNode current = first;
while (current) {
current->parent = new_parent;
current = current->next;
}
}
void ASTZipper::DetachTail(ASTNode node) {
ASSERT(node->manager == this);
if (node == first) {
first.reset();
last.reset();
return;
}
last = node->previous;
node->previous.reset();
}
void ASTZipper::DetachSegment(ASTNode start, ASTNode end) {
ASSERT(start->manager == this && end->manager == this);
ASTNode prev = start->previous;
ASTNode post = end->next;
if (!prev) {
first = post;
} else {
prev->next = post;
}
if (!post) {
last = prev;
} else {
post->previous = prev;
}
start->previous.reset();
end->next.reset();
ASTNode current = start;
bool found = false;
while (current) {
current->manager = nullptr;
current->parent.reset();
found |= current == end;
current = current->next;
}
ASSERT(found);
}
void ASTZipper::DetachSingle(ASTNode node) {
ASSERT(node->manager == this);
ASTNode prev = node->previous;
ASTNode post = node->next;
node->previous.reset();
node->next.reset();
if (!prev) {
first = post;
} else {
prev->next = post;
}
if (!post) {
last = prev;
} else {
post->previous = prev;
}
node->manager = nullptr;
node->parent.reset();
}
void ASTZipper::Remove(ASTNode node) {
ASSERT(node->manager == this);
ASTNode next = node->next;
ASTNode previous = node->previous;
if (previous) {
previous->next = next;
}
if (next) {
next->previous = previous;
}
node->parent.reset();
node->manager = nullptr;
if (node == last) {
last = previous;
}
if (node == first) {
first = next;
}
}
class ExprPrinter final { class ExprPrinter final {
public: public:
ExprPrinter() = default; ExprPrinter() = default;
@ -72,32 +213,39 @@ public:
void operator()(ASTProgram& ast) { void operator()(ASTProgram& ast) {
scope++; scope++;
inner += "program {\n"; inner += "program {\n";
for (ASTNode& node : ast.nodes) { ASTNode current = ast.nodes.GetFirst();
Visit(node); while (current) {
Visit(current);
current = current->GetNext();
} }
inner += "}\n"; inner += "}\n";
scope--; scope--;
} }
void operator()(ASTIf& ast) { void operator()(ASTIfThen& ast) {
ExprPrinter expr_parser{}; ExprPrinter expr_parser{};
std::visit(expr_parser, *ast.condition); std::visit(expr_parser, *ast.condition);
inner += Ident() + "if (" + expr_parser.GetResult() + ") {\n"; inner += Ident() + "if (" + expr_parser.GetResult() + ") {\n";
scope++; scope++;
for (auto& node : ast.then_nodes) { ASTNode current = ast.nodes.GetFirst();
Visit(node); while (current) {
Visit(current);
current = current->GetNext();
} }
scope--; scope--;
if (ast.else_nodes.size() > 0) {
inner += Ident() + "} else {\n";
scope++;
for (auto& node : ast.else_nodes) {
Visit(node);
}
scope--;
} else {
inner += Ident() + "}\n"; inner += Ident() + "}\n";
} }
void operator()(ASTIfElse& ast) {
inner += Ident() + "else {\n";
scope++;
ASTNode current = ast.nodes.GetFirst();
while (current) {
Visit(current);
current = current->GetNext();
}
scope--;
inner += Ident() + "}\n";
} }
void operator()(ASTBlockEncoded& ast) { void operator()(ASTBlockEncoded& ast) {
@ -128,8 +276,10 @@ public:
std::visit(expr_parser, *ast.condition); std::visit(expr_parser, *ast.condition);
inner += Ident() + "do {\n"; inner += Ident() + "do {\n";
scope++; scope++;
for (auto& node : ast.loop_nodes) { ASTNode current = ast.nodes.GetFirst();
Visit(node); while (current) {
Visit(current);
current = current->GetNext();
} }
scope--; scope--;
inner += Ident() + "} while (" + expr_parser.GetResult() + ")\n"; inner += Ident() + "} while (" + expr_parser.GetResult() + ")\n";
@ -142,6 +292,12 @@ public:
(ast.kills ? "discard" : "exit") + ";\n"; (ast.kills ? "discard" : "exit") + ";\n";
} }
void operator()(ASTBreak& ast) {
ExprPrinter expr_parser{};
std::visit(expr_parser, *ast.condition);
inner += Ident() + "(" + expr_parser.GetResult() + ") -> break;\n";
}
std::string& Ident() { std::string& Ident() {
if (memo_scope == scope) { if (memo_scope == scope) {
return tabs_memo; return tabs_memo;
@ -177,4 +333,164 @@ std::string ASTManager::Print() {
return printer.GetResult(); return printer.GetResult();
} }
#pragma optimize("", off)
void ASTManager::Decompile() {
auto it = gotos.begin();
while (it != gotos.end()) {
ASTNode goto_node = *it;
u32 label_index = goto_node->GetGotoLabel();
ASTNode label = labels[label_index];
if (IndirectlyRelated(goto_node, label)) {
while (!DirectlyRelated(goto_node, label)) {
MoveOutward(goto_node);
}
}
if (DirectlyRelated(goto_node, label)) {
u32 goto_level = goto_node->GetLevel();
u32 label_level = goto_node->GetLevel();
while (label_level > goto_level) {
MoveOutward(goto_node);
goto_level++;
}
}
if (label->GetParent() == goto_node->GetParent()) {
bool is_loop = false;
ASTNode current = goto_node->GetPrevious();
while (current) {
if (current == label) {
is_loop = true;
break;
}
current = current->GetPrevious();
}
if (is_loop) {
EncloseDoWhile(goto_node, label);
} else {
EncloseIfThen(goto_node, label);
}
it = gotos.erase(it);
continue;
}
it++;
}
/*
for (ASTNode label : labels) {
auto& manager = label->GetManager();
manager.Remove(label);
}
labels.clear();
*/
}
bool ASTManager::IndirectlyRelated(ASTNode first, ASTNode second) {
return !(first->GetParent() == second->GetParent() || DirectlyRelated(first, second));
}
bool ASTManager::DirectlyRelated(ASTNode first, ASTNode second) {
if (first->GetParent() == second->GetParent()) {
return false;
}
u32 first_level = first->GetLevel();
u32 second_level = second->GetLevel();
u32 min_level;
u32 max_level;
ASTNode max;
ASTNode min;
if (first_level > second_level) {
min_level = second_level;
min = second;
max_level = first_level;
max = first;
} else {
min_level = first_level;
min = first;
max_level = second_level;
max = second;
}
while (min_level < max_level) {
min_level++;
min = min->GetParent();
}
return (min->GetParent() == max->GetParent());
}
void ASTManager::EncloseDoWhile(ASTNode goto_node, ASTNode label) {
ASTZipper& zipper = goto_node->GetManager();
ASTNode loop_start = label->GetNext();
if (loop_start == goto_node) {
zipper.Remove(goto_node);
return;
}
ASTNode parent = label->GetParent();
Expr condition = goto_node->GetGotoCondition();
zipper.DetachSegment(loop_start, goto_node);
ASTNode do_while_node = ASTBase::Make<ASTDoWhile>(parent, condition, ASTZipper(loop_start));
zipper.InsertAfter(do_while_node, label);
ASTZipper* sub_zipper = do_while_node->GetSubNodes();
sub_zipper->SetParent(do_while_node);
sub_zipper->Remove(goto_node);
}
void ASTManager::EncloseIfThen(ASTNode goto_node, ASTNode label) {
ASTZipper& zipper = goto_node->GetManager();
ASTNode if_end = label->GetPrevious();
if (if_end == goto_node) {
zipper.Remove(goto_node);
return;
}
ASTNode prev = goto_node->GetPrevious();
ASTNode parent = label->GetParent();
Expr condition = goto_node->GetGotoCondition();
Expr neg_condition = MakeExpr<ExprNot>(condition);
zipper.DetachSegment(goto_node, if_end);
ASTNode if_node = ASTBase::Make<ASTIfThen>(parent, condition, ASTZipper(goto_node));
zipper.InsertAfter(if_node, prev);
ASTZipper* sub_zipper = if_node->GetSubNodes();
sub_zipper->SetParent(if_node);
sub_zipper->Remove(goto_node);
}
void ASTManager::MoveOutward(ASTNode goto_node) {
ASTZipper& zipper = goto_node->GetManager();
ASTNode parent = goto_node->GetParent();
bool is_loop = parent->IsLoop();
bool is_if = parent->IsIfThen() || parent->IsIfElse();
ASTNode prev = goto_node->GetPrevious();
Expr condition = goto_node->GetGotoCondition();
u32 var_index = NewVariable();
Expr var_condition = MakeExpr<ExprVar>(var_index);
ASTNode var_node = ASTBase::Make<ASTVarSet>(parent, var_index, condition);
zipper.DetachSingle(goto_node);
zipper.InsertAfter(var_node, prev);
goto_node->SetGotoCondition(var_condition);
if (is_loop) {
ASTNode break_node = ASTBase::Make<ASTBreak>(parent, var_condition);
zipper.InsertAfter(break_node, var_node);
} else if (is_if) {
ASTNode post = var_node->GetNext();
if (post) {
zipper.DetachTail(post);
ASTNode if_node = ASTBase::Make<ASTIfThen>(parent, var_condition, ASTZipper(post));
zipper.InsertAfter(if_node, var_node);
ASTZipper* sub_zipper = if_node->GetSubNodes();
sub_zipper->SetParent(if_node);
}
} else {
UNREACHABLE();
}
ASTZipper& zipper2 = parent->GetManager();
ASTNode next = parent->GetNext();
if (is_if && next && next->IsIfElse()) {
zipper2.InsertAfter(goto_node, next);
return;
}
zipper2.InsertAfter(goto_node, parent);
}
} // namespace VideoCommon::Shader } // namespace VideoCommon::Shader

View file

@ -18,32 +18,71 @@ namespace VideoCommon::Shader {
class ASTBase; class ASTBase;
class ASTProgram; class ASTProgram;
class ASTIf; class ASTIfThen;
class ASTIfElse;
class ASTBlockEncoded; class ASTBlockEncoded;
class ASTVarSet; class ASTVarSet;
class ASTGoto; class ASTGoto;
class ASTLabel; class ASTLabel;
class ASTDoWhile; class ASTDoWhile;
class ASTReturn; class ASTReturn;
class ASTBreak;
using ASTData = std::variant<ASTProgram, ASTIf, ASTBlockEncoded, ASTVarSet, ASTGoto, ASTLabel, using ASTData = std::variant<ASTProgram, ASTIfThen, ASTIfElse, ASTBlockEncoded, ASTVarSet, ASTGoto,
ASTDoWhile, ASTReturn>; ASTLabel, ASTDoWhile, ASTReturn, ASTBreak>;
using ASTNode = std::shared_ptr<ASTBase>; using ASTNode = std::shared_ptr<ASTBase>;
class ASTProgram { enum class ASTZipperType : u32 {
public: Program,
ASTProgram() = default; IfThen,
std::list<ASTNode> nodes; IfElse,
Loop,
}; };
class ASTIf { class ASTZipper final {
public: public:
ASTIf(Expr condition, std::list<ASTNode> then_nodes, std::list<ASTNode> else_nodes) ASTZipper();
: condition(condition), then_nodes{then_nodes}, else_nodes{then_nodes} {} ASTZipper(ASTNode first);
ASTNode GetFirst() {
return first;
}
ASTNode GetLast() {
return last;
}
void PushBack(ASTNode new_node);
void PushFront(ASTNode new_node);
void InsertAfter(ASTNode new_node, ASTNode at_node);
void SetParent(ASTNode new_parent);
void DetachTail(ASTNode node);
void DetachSingle(ASTNode node);
void DetachSegment(ASTNode start, ASTNode end);
void Remove(ASTNode node);
ASTNode first{};
ASTNode last{};
};
class ASTProgram {
public:
ASTProgram() : nodes{} {};
ASTZipper nodes;
};
class ASTIfThen {
public:
ASTIfThen(Expr condition, ASTZipper nodes) : condition(condition), nodes{nodes} {}
Expr condition; Expr condition;
std::list<ASTNode> then_nodes; ASTZipper nodes;
std::list<ASTNode> else_nodes; };
class ASTIfElse {
public:
ASTIfElse(ASTZipper nodes) : nodes{nodes} {}
ASTZipper nodes;
}; };
class ASTBlockEncoded { class ASTBlockEncoded {
@ -75,10 +114,9 @@ public:
class ASTDoWhile { class ASTDoWhile {
public: public:
ASTDoWhile(Expr condition, std::list<ASTNode> loop_nodes) ASTDoWhile(Expr condition, ASTZipper nodes) : condition(condition), nodes{nodes} {}
: condition(condition), loop_nodes{loop_nodes} {}
Expr condition; Expr condition;
std::list<ASTNode> loop_nodes; ASTZipper nodes;
}; };
class ASTReturn { class ASTReturn {
@ -88,6 +126,12 @@ public:
bool kills; bool kills;
}; };
class ASTBreak {
public:
ASTBreak(Expr condition) : condition{condition} {}
Expr condition;
};
class ASTBase { class ASTBase {
public: public:
explicit ASTBase(ASTNode parent, ASTData data) : parent{parent}, data{data} {} explicit ASTBase(ASTNode parent, ASTData data) : parent{parent}, data{data} {}
@ -111,9 +155,9 @@ public:
u32 GetLevel() const { u32 GetLevel() const {
u32 level = 0; u32 level = 0;
auto next = parent; auto next_parent = parent;
while (next) { while (next_parent) {
next = next->GetParent(); next_parent = next_parent->GetParent();
level++; level++;
} }
return level; return level;
@ -123,15 +167,83 @@ public:
return &data; return &data;
} }
ASTNode GetNext() {
return next;
}
ASTNode GetPrevious() {
return previous;
}
ASTZipper& GetManager() {
return *manager;
}
u32 GetGotoLabel() const {
auto inner = std::get_if<ASTGoto>(&data);
if (inner) {
return inner->label;
}
return -1;
}
Expr GetGotoCondition() const {
auto inner = std::get_if<ASTGoto>(&data);
if (inner) {
return inner->condition;
}
return nullptr;
}
void SetGotoCondition(Expr new_condition) {
auto inner = std::get_if<ASTGoto>(&data);
if (inner) {
inner->condition = new_condition;
}
}
bool IsIfThen() const {
return std::holds_alternative<ASTIfThen>(data);
}
bool IsIfElse() const {
return std::holds_alternative<ASTIfElse>(data);
}
bool IsLoop() const {
return std::holds_alternative<ASTDoWhile>(data);
}
ASTZipper* GetSubNodes() {
if (std::holds_alternative<ASTProgram>(data)) {
return &std::get_if<ASTProgram>(&data)->nodes;
}
if (std::holds_alternative<ASTIfThen>(data)) {
return &std::get_if<ASTIfThen>(&data)->nodes;
}
if (std::holds_alternative<ASTIfElse>(data)) {
return &std::get_if<ASTIfElse>(&data)->nodes;
}
if (std::holds_alternative<ASTDoWhile>(data)) {
return &std::get_if<ASTDoWhile>(&data)->nodes;
}
return nullptr;
}
private: private:
friend class ASTZipper;
ASTData data; ASTData data;
ASTNode parent; ASTNode parent;
ASTNode next{};
ASTNode previous{};
ASTZipper* manager{};
}; };
class ASTManager final { class ASTManager final {
public: public:
explicit ASTManager() { explicit ASTManager() {
main_node = ASTBase::Make<ASTProgram>(nullptr); main_node = ASTBase::Make<ASTProgram>(ASTNode{});
program = std::get_if<ASTProgram>(main_node->GetInnerData()); program = std::get_if<ASTProgram>(main_node->GetInnerData());
} }
@ -147,31 +259,49 @@ public:
u32 index = labels_map[address]; u32 index = labels_map[address];
ASTNode label = ASTBase::Make<ASTLabel>(main_node, index); ASTNode label = ASTBase::Make<ASTLabel>(main_node, index);
labels[index] = label; labels[index] = label;
program->nodes.push_back(label); program->nodes.PushBack(label);
} }
void InsertGoto(Expr condition, u32 address) { void InsertGoto(Expr condition, u32 address) {
u32 index = labels_map[address]; u32 index = labels_map[address];
ASTNode goto_node = ASTBase::Make<ASTGoto>(main_node, condition, index); ASTNode goto_node = ASTBase::Make<ASTGoto>(main_node, condition, index);
gotos.push_back(goto_node); gotos.push_back(goto_node);
program->nodes.push_back(goto_node); program->nodes.PushBack(goto_node);
} }
void InsertBlock(u32 start_address, u32 end_address) { void InsertBlock(u32 start_address, u32 end_address) {
ASTNode block = ASTBase::Make<ASTBlockEncoded>(main_node, start_address, end_address); ASTNode block = ASTBase::Make<ASTBlockEncoded>(main_node, start_address, end_address);
program->nodes.push_back(block); program->nodes.PushBack(block);
} }
void InsertReturn(Expr condition, bool kills) { void InsertReturn(Expr condition, bool kills) {
ASTNode node = ASTBase::Make<ASTReturn>(main_node, condition, kills); ASTNode node = ASTBase::Make<ASTReturn>(main_node, condition, kills);
program->nodes.push_back(node); program->nodes.PushBack(node);
} }
std::string Print(); std::string Print();
void Decompile() {} void Decompile();
private: private:
bool IndirectlyRelated(ASTNode first, ASTNode second);
bool DirectlyRelated(ASTNode first, ASTNode second);
void EncloseDoWhile(ASTNode goto_node, ASTNode label);
void EncloseIfThen(ASTNode goto_node, ASTNode label);
void MoveOutward(ASTNode goto_node) ;
u32 NewVariable() {
u32 new_var = variables;
variables++;
return new_var;
}
std::unordered_map<u32, u32> labels_map{}; std::unordered_map<u32, u32> labels_map{};
u32 labels_count{}; u32 labels_count{};
std::vector<ASTNode> labels{}; std::vector<ASTNode> labels{};