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shader_ir: Corrections, documenting and asserting control_flow

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This commit is contained in:
Fernando Sahmkow 2019-06-25 20:15:40 -04:00 committed by FernandoS27
parent d5533b440c
commit 01b21ee1e8
3 changed files with 54 additions and 52 deletions
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78
src/video_core/shader/control_flow.cpp
View file

@ -1,3 +1,6 @@
// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <list>
#include <map>
@ -17,16 +20,18 @@ 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 {
std::array<u32, 20> stack;
static constexpr std::size_t stack_fixed_size = 20;
std::array<u32, stack_fixed_size> stack{};
u32 index{};
ControlStack() {}
ControlStack(const ControlStack& cp) {
index = cp.index;
std::memcpy(stack.data(), cp.stack.data(), index * sizeof(u32));
}
ControlStack(const ControlStack& cp) = default;
bool Compare(const ControlStack& cs) const {
if (index != cs.index) {
@ -35,6 +40,7 @@ struct ControlStack {
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;
@ -51,7 +57,7 @@ struct ControlStack {
}
bool Push(u32 address) {
if (index >= 20) {
if (index >= stack.size()) {
return false;
}
stack[index] = address;
@ -70,21 +76,23 @@ struct ControlStack {
struct Query {
Query() {}
Query(const Query& q) : address{q.address}, ssy_stack{q.ssy_stack}, pbk_stack{q.pbk_stack} {}
u32 address;
Query(const Query& q) = default;
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 BlockStack& b) = default;
BlockStack(const Query& q) : ssy_stack{q.ssy_stack}, pbk_stack{q.pbk_stack} {}
ControlStack ssy_stack{};
ControlStack pbk_stack{};
};
struct BlockBranchInfo {
BlockBranchInfo() = default;
BlockBranchInfo(const BlockBranchInfo& b) = default;
Condition condition{};
s32 address{exit_branch};
bool kill{};
@ -94,7 +102,7 @@ struct BlockBranchInfo {
};
struct BlockInfo {
BlockInfo() {}
BlockInfo() = default;
u32 start{};
u32 end{};
bool visited{};
@ -107,24 +115,15 @@ struct BlockInfo {
struct CFGRebuildState {
explicit CFGRebuildState(const ProgramCode& program_code, const std::size_t program_size)
: program_code{program_code}, program_size{program_size} {
// queries.clear();
block_info.clear();
labels.clear();
registered.clear();
ssy_labels.clear();
pbk_labels.clear();
inspect_queries.clear();
queries.clear();
}
: program_code{program_code}, program_size{program_size} {}
std::vector<BlockInfo> block_info{};
std::list<u32> inspect_queries{};
std::list<Query> queries{};
std::unordered_map<u32, u32> registered{};
std::unordered_set<u32> labels{};
std::map<u32, u32> ssy_labels;
std::map<u32, u32> pbk_labels;
std::map<u32, u32> ssy_labels{};
std::map<u32, u32> pbk_labels{};
std::unordered_map<u32, BlockStack> stacks{};
const ProgramCode& program_code;
const std::size_t program_size;
@ -156,7 +155,7 @@ BlockInfo* CreateBlockInfo(CFGRebuildState& state, u32 start, u32 end) {
auto& it = state.block_info.emplace_back();
it.start = start;
it.end = end;
u32 index = state.block_info.size() - 1;
const u32 index = static_cast<u32>(state.block_info.size() - 1);
state.registered.insert({start, index});
return &it;
}
@ -172,11 +171,10 @@ enum class ParseResult : u32 {
};
ParseResult ParseCode(CFGRebuildState& state, u32 address, ParseInfo& parse_info) {
u32 offset = static_cast<u32>(address);
u32 end_address = static_cast<u32>(state.program_size - 10U) * 8U;
const u32 end_address = static_cast<u32>(state.program_size - 10U) * 8U;
auto insert_label = ([](CFGRebuildState& state, u32 address) {
const auto insert_label = ([](CFGRebuildState& state, u32 address) {
auto pair = state.labels.emplace(address);
if (pair.second) {
state.inspect_queries.push_back(address);
@ -361,20 +359,18 @@ bool TryInspectAddress(CFGRebuildState& state) {
if (state.inspect_queries.empty()) {
return false;
}
u32 address = state.inspect_queries.front();
const u32 address = state.inspect_queries.front();
state.inspect_queries.pop_front();
auto search_result = TryGetBlock(state, address);
BlockInfo* block_info;
const auto search_result = TryGetBlock(state, address);
switch (search_result.first) {
case BlockCollision::Found: {
return true;
break;
}
case BlockCollision::Inside: {
// This case is the tricky one:
// We need to Split the block in 2 sepparate blocks
auto it = search_result.second;
block_info = CreateBlockInfo(state, address, it->end);
BlockInfo* block_info = CreateBlockInfo(state, address, it->end);
it->end = address - 1;
block_info->branch = it->branch;
BlockBranchInfo forward_branch{};
@ -382,34 +378,32 @@ bool TryInspectAddress(CFGRebuildState& state) {
forward_branch.ignore = true;
it->branch = forward_branch;
return true;
break;
}
default:
break;
}
ParseInfo parse_info;
ParseResult parse_result = ParseCode(state, address, parse_info);
const ParseResult parse_result = ParseCode(state, address, parse_info);
if (parse_result == ParseResult::AbnormalFlow) {
// if it's the end of the program, end it safely
// if it's AbnormalFlow, we end it as false, ending the CFG reconstruction
return false;
}
block_info = CreateBlockInfo(state, address, parse_info.end_address);
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;
}
u32 fallthrough_address = parse_info.end_address + 1;
const u32 fallthrough_address = parse_info.end_address + 1;
state.inspect_queries.push_front(fallthrough_address);
return true;
}
bool TryQuery(CFGRebuildState& state) {
auto gather_labels = ([](ControlStack& cc, std::map<u32, u32>& labels, BlockInfo& block) {
const auto gather_labels = ([](ControlStack& cc, std::map<u32, u32>& labels, BlockInfo& block) {
auto gather_start = labels.lower_bound(block.start);
auto gather_end = labels.upper_bound(block.end);
const auto gather_end = labels.upper_bound(block.end);
while (gather_start != gather_end) {
cc.Push(gather_start->second);
gather_start++;
@ -419,21 +413,21 @@ bool TryQuery(CFGRebuildState& state) {
return false;
}
Query& q = state.queries.front();
u32 block_index = state.registered[q.address];
const u32 block_index = state.registered[q.address];
BlockInfo& block = state.block_info[block_index];
// If the block is visted, check if the stacks match, else gather the ssy/pbk
// labels into the current stack and look if the branch at the end of the block
// consumes a label. Schedule new queries accordingly
if (block.visited) {
BlockStack& stack = state.stacks[q.address];
bool all_okay = (stack.ssy_stack.Size() == 0 || q.ssy_stack.Compare(stack.ssy_stack)) &&
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));
state.queries.pop_front();
return all_okay;
}
block.visited = true;
BlockStack bs{q};
state.stacks[q.address] = bs;
state.stacks[q.address] = BlockStack{q};
Query q2(q);
state.queries.pop_front();
gather_labels(q2.ssy_stack, state.ssy_labels, block);

16
src/video_core/shader/control_flow.h
View file

@ -1,3 +1,7 @@
// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <cstring>
@ -20,12 +24,15 @@ struct Condition {
ConditionCode cc{ConditionCode::T};
bool IsUnconditional() const {
return (predicate == Pred::UnusedIndex) && (cc == ConditionCode::T);
return predicate == Pred::UnusedIndex && cc == ConditionCode::T;
}
bool operator==(const Condition& other) const {
return std::tie(predicate, cc) == std::tie(other.predicate, other.cc);
}
};
struct ShaderBlock {
ShaderBlock() {}
ShaderBlock() = default;
ShaderBlock(const ShaderBlock& sb) = default;
u32 start{};
u32 end{};
@ -35,11 +42,12 @@ struct ShaderBlock {
bool kills{};
s32 address{};
bool operator==(const Branch& b) const {
return std::memcmp(this, &b, sizeof(Branch)) == 0;
return std::tie(cond, kills, address) == std::tie(b.cond, b.kills, b.address);
}
} branch;
bool operator==(const ShaderBlock& sb) const {
return std::memcmp(this, &sb, sizeof(ShaderBlock)) == 0;
return std::tie(start, end, ignore_branch, branch) ==
std::tie(sb.start, sb.end, sb.ignore_branch, sb.branch);
}
};

10
src/video_core/shader/decode.cpp
View file

@ -46,7 +46,7 @@ void ShaderIR::Decode() {
coverage_end = shader_info.end;
if (shader_info.decompilable) {
disable_flow_stack = true;
auto insert_block = ([this](NodeBlock& nodes, u32 label) {
const auto insert_block = ([this](NodeBlock& nodes, u32 label) {
if (label == exit_branch) {
return;
}
@ -88,7 +88,6 @@ void ShaderIR::Decode() {
for (u32 label = main_offset; label < shader_end; label++) {
basic_blocks.insert({label, DecodeRange(label, label + 1)});
}
return;
}
NodeBlock ShaderIR::DecodeRange(u32 begin, u32 end) {
@ -104,16 +103,17 @@ void ShaderIR::DecodeRangeInner(NodeBlock& bb, u32 begin, u32 end) {
}
void ShaderIR::InsertControlFlow(NodeBlock& bb, const ShaderBlock& block) {
auto apply_conditions = ([&](const Condition& cond, Node n) -> Node {
const auto apply_conditions = ([&](const Condition& cond, Node n) -> Node {
Node result = n;
if (cond.cc != ConditionCode::T) {
result = Conditional(GetConditionCode(cond.cc), {result});
}
if (cond.predicate != Pred::UnusedIndex) {
u32 pred = static_cast<u32>(cond.predicate);
bool is_neg = pred > 7;
if (is_neg)
const bool is_neg = pred > 7;
if (is_neg) {
pred -= 8;
}
result = Conditional(GetPredicate(pred, is_neg), {result});
}
return result;