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control_flow: Address feedback.

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This commit is contained in:
Fernando Sahmkow 2019-06-26 12:56:03 -04:00 committed by FernandoS27
parent 34357b110c
commit e7a88f0ab3
1 changed files with 37 additions and 89 deletions
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126
src/video_core/shader/control_flow.cpp
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@ -4,6 +4,7 @@
#include <list>
#include <map>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>
@ -20,68 +21,18 @@ using Tegra::Shader::OpCode;
constexpr s32 unassigned_branch = -2;
/**
* 'ControlStack' represents a static stack of control jumps such as SSY and PBK
* stacks in Maxwell.
**/
struct ControlStack {
static constexpr std::size_t stack_fixed_size = 20;
std::array<u32, stack_fixed_size> stack{};
u32 index{};
bool Compare(const ControlStack& cs) const {
if (index != cs.index) {
return false;
}
return std::memcmp(stack.data(), cs.stack.data(), index * sizeof(u32)) == 0;
}
/// This compare just compares the top of the stack against one another
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 >= stack.size()) {
return false;
}
stack[index] = address;
index++;
return true;
}
bool Pop() {
if (index == 0) {
return false;
}
index--;
return true;
}
};
struct Query {
u32 address{};
ControlStack ssy_stack{};
ControlStack pbk_stack{};
std::stack<u32> ssy_stack{};
std::stack<u32> pbk_stack{};
};
struct BlockStack {
BlockStack() = default;
BlockStack(const BlockStack& b) = default;
BlockStack(const Query& q) : ssy_stack{q.ssy_stack}, pbk_stack{q.pbk_stack} {}
ControlStack ssy_stack{};
ControlStack pbk_stack{};
std::stack<u32> ssy_stack{};
std::stack<u32> pbk_stack{};
};
struct BlockBranchInfo {
@ -144,13 +95,13 @@ struct ParseInfo {
u32 end_address{};
};
BlockInfo* CreateBlockInfo(CFGRebuildState& state, u32 start, u32 end) {
BlockInfo& CreateBlockInfo(CFGRebuildState& state, u32 start, u32 end) {
auto& it = state.block_info.emplace_back();
it.start = start;
it.end = end;
const u32 index = static_cast<u32>(state.block_info.size() - 1);
state.registered.insert({start, index});
return &it;
return it;
}
Pred GetPredicate(u32 index, bool negated) {
@ -174,16 +125,17 @@ enum class ParseResult : u32 {
AbnormalFlow,
};
ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info) {
std::pair<ParseResult, ParseInfo> ParseCode(CFGRebuildState& state, u32 address) {
u32 offset = static_cast<u32>(address);
const u32 end_address = static_cast<u32>(state.program_size / sizeof(Instruction));
ParseInfo parse_info{};
const auto insert_label = ([](CFGRebuildState& state, u32 address) {
auto pair = state.labels.emplace(address);
const auto insert_label = [](CFGRebuildState& state, u32 address) {
const auto pair = state.labels.emplace(address);
if (pair.second) {
state.inspect_queries.push_back(address);
}
});
};
while (true) {
if (offset >= end_address) {
@ -229,11 +181,11 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
return {ParseResult::ControlCaught, parse_info};
}
case OpCode::Id::BRA: {
if (instr.bra.constant_buffer != 0) {
return ParseResult::AbnormalFlow;
return {ParseResult::AbnormalFlow, parse_info};
}
const auto pred_index = static_cast<u32>(instr.pred.pred_index);
parse_info.branch_info.condition.predicate =
@ -248,7 +200,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
offset++;
continue;
}
u32 branch_offset = offset + instr.bra.GetBranchTarget();
const u32 branch_offset = offset + instr.bra.GetBranchTarget();
if (branch_offset == 0) {
parse_info.branch_info.address = exit_branch;
} else {
@ -261,10 +213,9 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
return {ParseResult::ControlCaught, parse_info};
}
case OpCode::Id::SYNC: {
parse_info.branch_info.condition;
const auto pred_index = static_cast<u32>(instr.pred.pred_index);
parse_info.branch_info.condition.predicate =
GetPredicate(pred_index, instr.negate_pred != 0);
@ -285,10 +236,9 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
return {ParseResult::ControlCaught, parse_info};
}
case OpCode::Id::BRK: {
parse_info.branch_info.condition;
const auto pred_index = static_cast<u32>(instr.pred.pred_index);
parse_info.branch_info.condition.predicate =
GetPredicate(pred_index, instr.negate_pred != 0);
@ -309,10 +259,9 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
return {ParseResult::ControlCaught, parse_info};
}
case OpCode::Id::KIL: {
parse_info.branch_info.condition;
const auto pred_index = static_cast<u32>(instr.pred.pred_index);
parse_info.branch_info.condition.predicate =
GetPredicate(pred_index, instr.negate_pred != 0);
@ -333,7 +282,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.ignore = false;
parse_info.end_address = offset;
return ParseResult::ControlCaught;
return {ParseResult::ControlCaught, parse_info};
}
case OpCode::Id::SSY: {
const u32 target = offset + instr.bra.GetBranchTarget();
@ -348,7 +297,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
break;
}
case OpCode::Id::BRX: {
return ParseResult::AbnormalFlow;
return {ParseResult::AbnormalFlow, parse_info};
}
default:
break;
@ -360,7 +309,7 @@ ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info
parse_info.branch_info.is_sync = false;
parse_info.branch_info.is_brk = false;
parse_info.end_address = offset - 1;
return ParseResult::BlockEnd;
return {ParseResult::BlockEnd, parse_info};
}
bool TryInspectAddress(CFGRebuildState& state) {
@ -377,10 +326,10 @@ bool TryInspectAddress(CFGRebuildState& state) {
case BlockCollision::Inside: {
// This case is the tricky one:
// We need to Split the block in 2 sepparate blocks
auto it = search_result.second;
BlockInfo* block_info = CreateBlockInfo(state, address, it->end);
const auto it = search_result.second;
BlockInfo& block_info = CreateBlockInfo(state, address, it->end);
it->end = address - 1;
block_info->branch = it->branch;
block_info.branch = it->branch;
BlockBranchInfo forward_branch{};
forward_branch.address = address;
forward_branch.ignore = true;
@ -390,15 +339,14 @@ bool TryInspectAddress(CFGRebuildState& state) {
default:
break;
}
ParseInfo parse_info;
const ParseResult parse_result = ParseCode(state, address, parse_info);
const auto [parse_result, parse_info] = ParseCode(state, address);
if (parse_result == ParseResult::AbnormalFlow) {
// if it's AbnormalFlow, we end it as false, ending the CFG reconstruction
return false;
}
BlockInfo* block_info = CreateBlockInfo(state, address, parse_info.end_address);
block_info->branch = parse_info.branch_info;
BlockInfo& block_info = CreateBlockInfo(state, address, parse_info.end_address);
block_info.branch = parse_info.branch_info;
if (parse_info.branch_info.condition.IsUnconditional()) {
return true;
}
@ -409,14 +357,15 @@ bool TryInspectAddress(CFGRebuildState& state) {
}
bool TryQuery(CFGRebuildState& state) {
const auto gather_labels = ([](ControlStack& cc, std::map<u32, u32>& labels, BlockInfo& block) {
const auto gather_labels = [](std::stack<u32>& cc, std::map<u32, u32>& labels,
BlockInfo& block) {
auto gather_start = labels.lower_bound(block.start);
const auto gather_end = labels.upper_bound(block.end);
while (gather_start != gather_end) {
cc.Push(gather_start->second);
cc.push(gather_start->second);
gather_start++;
}
});
};
if (state.queries.empty()) {
return false;
}
@ -428,9 +377,8 @@ bool TryQuery(CFGRebuildState& state) {
// consumes a label. Schedule new queries accordingly
if (block.visited) {
BlockStack& stack = state.stacks[q.address];
const bool all_okay =
(stack.ssy_stack.Size() == 0 || q.ssy_stack.Compare(stack.ssy_stack)) &&
(stack.pbk_stack.Size() == 0 || q.pbk_stack.Compare(stack.pbk_stack));
const bool all_okay = (stack.ssy_stack.size() == 0 || q.ssy_stack == stack.ssy_stack) &&
(stack.pbk_stack.size() == 0 || q.pbk_stack == stack.pbk_stack);
state.queries.pop_front();
return all_okay;
}
@ -447,15 +395,15 @@ bool TryQuery(CFGRebuildState& state) {
Query conditional_query{q2};
if (block.branch.is_sync) {
if (block.branch.address == unassigned_branch) {
block.branch.address = conditional_query.ssy_stack.Top();
block.branch.address = conditional_query.ssy_stack.top();
}
conditional_query.ssy_stack.Pop();
conditional_query.ssy_stack.pop();
}
if (block.branch.is_brk) {
if (block.branch.address == unassigned_branch) {
block.branch.address = conditional_query.pbk_stack.Top();
block.branch.address = conditional_query.pbk_stack.top();
}
conditional_query.pbk_stack.Pop();
conditional_query.pbk_stack.pop();
}
conditional_query.address = block.branch.address;
state.queries.push_back(conditional_query);