shader_ir: Decompile Flow Stack

This commit is contained in:
Fernando Sahmkow 2019-06-25 11:10:45 -04:00 committed by FernandoS27
parent 92be9d01aa
commit d7b3d3a823
4 changed files with 206 additions and 11 deletions
src/video_core/shader

View file

@ -1,6 +1,6 @@
#include <list>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <vector>
@ -16,12 +16,80 @@ using Tegra::Shader::OpCode;
constexpr s32 unassigned_branch = -2;
struct ControlStack {
std::array<u32, 20> stack;
u32 index{};
ControlStack() {}
ControlStack(const ControlStack& cp) {
index = cp.index;
std::memcpy(stack.data(), cp.stack.data(), index * sizeof(u32));
}
bool Compare(const ControlStack& cs) const {
if (index != cs.index) {
return false;
}
return std::memcmp(stack.data(), cs.stack.data(), index * sizeof(u32)) == 0;
}
bool SoftCompare(const ControlStack& cs) const {
if (index == 0 || cs.index == 0) {
return index == cs.index;
}
return Top() == cs.Top();
}
u32 Size() const {
return index;
}
u32 Top() const {
return stack[index - 1];
}
bool Push(u32 address) {
if (index >= 20) {
return false;
}
stack[index] = address;
index++;
return true;
}
bool Pop() {
if (index == 0) {
return false;
}
index--;
return true;
}
};
struct Query {
Query() {}
Query(const Query& q) : address{q.address}, ssy_stack{q.ssy_stack}, pbk_stack{q.pbk_stack} {}
u32 address;
ControlStack ssy_stack{};
ControlStack pbk_stack{};
};
struct BlockStack {
BlockStack() = default;
BlockStack(const BlockStack& b) : ssy_stack{b.ssy_stack}, pbk_stack{b.pbk_stack} {}
BlockStack(const Query& q) : ssy_stack{q.ssy_stack}, pbk_stack{q.pbk_stack} {}
ControlStack ssy_stack{};
ControlStack pbk_stack{};
};
struct BlockBranchInfo {
Condition condition{};
s32 address{exit_branch};
bool kill{};
bool is_sync{};
bool is_brk{};
bool ignore{};
};
struct BlockInfo {
@ -64,19 +132,21 @@ struct CFGRebuildState {
// queries.clear();
block_info.clear();
labels.clear();
visited_address.clear();
registered.clear();
ssy_labels.clear();
pbk_labels.clear();
inspect_queries.clear();
queries.clear();
}
std::vector<BlockInfo> block_info{};
std::list<u32> inspect_queries{};
// std::list<Query> queries{};
std::unordered_set<u32> visited_address{};
std::list<Query> queries{};
std::unordered_map<u32, u32> registered{};
std::unordered_set<u32> labels{};
std::set<Stamp> ssy_labels;
std::set<Stamp> pbk_labels;
std::unordered_map<u32, BlockStack> stacks{};
const ProgramCode& program_code;
const std::size_t program_size;
};
@ -107,7 +177,8 @@ BlockInfo* CreateBlockInfo(CFGRebuildState& state, u32 start, u32 end) {
auto& it = state.block_info.emplace_back();
it.start = start;
it.end = end;
state.visited_address.insert(start);
u32 index = state.block_info.size() - 1;
state.registered.insert({start, index});
return &it;
}
@ -136,10 +207,12 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
while (true) {
if (offset >= end_address) {
parse_info.branch_info.address = exit_branch;
parse_info.branch_info.ignore = false;
break;
}
if (state.visited_address.count(offset) != 0) {
if (state.registered.count(offset) != 0) {
parse_info.branch_info.address = offset;
parse_info.branch_info.ignore = true;
break;
}
const Instruction instr = {state.program_code[offset]};
@ -168,6 +241,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.kill = false;
parse_info.branch_info.is_sync = false;
parse_info.branch_info.is_brk = false;
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
@ -199,6 +273,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.kill = false;
parse_info.branch_info.is_sync = false;
parse_info.branch_info.is_brk = false;
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
@ -222,6 +297,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.kill = false;
parse_info.branch_info.is_sync = true;
parse_info.branch_info.is_brk = false;
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
@ -245,6 +321,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.kill = false;
parse_info.branch_info.is_sync = false;
parse_info.branch_info.is_brk = true;
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
@ -268,6 +345,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.kill = true;
parse_info.branch_info.is_sync = false;
parse_info.branch_info.is_brk = false;
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
@ -322,6 +400,7 @@ bool TryInspectAddress(CFGRebuildState& state) {
block_info->branch = it->branch;
BlockBranchInfo forward_branch{};
forward_branch.address = address;
forward_branch.ignore = true;
it->branch = forward_branch;
return true;
break;
@ -348,6 +427,58 @@ bool TryInspectAddress(CFGRebuildState& state) {
return true;
}
bool TryQuery(CFGRebuildState& state) {
auto gather_labels = ([](ControlStack& cc, std::set<Stamp> labels, BlockInfo& block) {
Stamp start{block.start, 0};
Stamp end{block.end, 0};
auto gather_start = labels.lower_bound(start);
auto gather_end = labels.upper_bound(end);
while (gather_start != gather_end) {
cc.Push(gather_start->target);
gather_start++;
}
});
if (state.queries.empty()) {
return false;
}
Query& q = state.queries.front();
u32 block_index = state.registered[q.address];
BlockInfo& block = state.block_info[block_index];
if (block.visited) {
BlockStack& stack = state.stacks[q.address];
bool all_okay = q.ssy_stack.Compare(stack.ssy_stack) && q.pbk_stack.Compare(stack.pbk_stack);
state.queries.pop_front();
return all_okay;
}
block.visited = true;
BlockStack bs{q};
state.stacks[q.address] = bs;
Query q2(q);
state.queries.pop_front();
gather_labels(q2.ssy_stack, state.ssy_labels, block);
gather_labels(q2.pbk_stack, state.pbk_labels, block);
if (!block.branch.condition.IsUnconditional()) {
q2.address = block.end + 1;
state.queries.push_back(q2);
}
Query conditional_query{q2};
if (block.branch.is_sync) {
if (block.branch.address == unassigned_branch) {
block.branch.address = conditional_query.ssy_stack.Top();
}
conditional_query.ssy_stack.Pop();
}
if (block.branch.is_brk) {
if (block.branch.address == unassigned_branch) {
block.branch.address = conditional_query.pbk_stack.Top();
}
conditional_query.pbk_stack.Pop();
}
conditional_query.address = block.branch.address;
state.queries.push_back(conditional_query);
return true;
}
bool ScanFlow(const ProgramCode& program_code, u32 program_size, u32 start_address,
ShaderCharacteristics& result_out) {
CFGRebuildState state{program_code, program_size};
@ -360,20 +491,34 @@ bool ScanFlow(const ProgramCode& program_code, u32 program_size, u32 start_addre
return false;
}
}
// Decompile Stacks
Query start_query{};
start_query.address = start_address;
state.queries.push_back(start_query);
bool decompiled = true;
while (!state.queries.empty()) {
if (!TryQuery(state)) {
decompiled = false;
break;
}
}
// Sort and organize results
std::sort(state.block_info.begin(), state.block_info.end(),
[](const BlockInfo& a, const BlockInfo& b) -> bool { return a.start < b.start; });
// Remove unvisited blocks
result_out.blocks.clear();
result_out.decompilable = false;
result_out.decompilable = decompiled;
result_out.start = start_address;
result_out.end = start_address;
for (auto& block : state.block_info) {
ShaderBlock new_block{};
new_block.start = block.start;
new_block.end = block.end;
new_block.branch.cond = block.branch.condition;
new_block.branch.kills = block.branch.kill;
new_block.branch.address = block.branch.address;
new_block.ignore_branch = block.branch.ignore;
if (!new_block.ignore_branch) {
new_block.branch.cond = block.branch.condition;
new_block.branch.kills = block.branch.kill;
new_block.branch.address = block.branch.address;
}
result_out.end = std::max(result_out.end, block.end);
result_out.blocks.push_back(new_block);
}