| |
| |
|
|
| #include <algorithm> |
| #include <array> |
| #include <bit> |
| #include <memory> |
|
|
| #include "common/common_types.h" |
| #include "common/polyfill_ranges.h" |
| #include "shader_recompiler/exception.h" |
| #include "shader_recompiler/frontend/maxwell/decode.h" |
| #include "shader_recompiler/frontend/maxwell/opcodes.h" |
|
|
| namespace Shader::Maxwell { |
| namespace { |
| struct MaskValue { |
| u64 mask; |
| u64 value; |
| }; |
|
|
| constexpr MaskValue MaskValueFromEncoding(const char* encoding) { |
| u64 mask{}; |
| u64 value{}; |
| u64 bit{u64(1) << 63}; |
| while (*encoding) { |
| switch (*encoding) { |
| case '0': |
| mask |= bit; |
| break; |
| case '1': |
| mask |= bit; |
| value |= bit; |
| break; |
| case '-': |
| break; |
| case ' ': |
| break; |
| default: |
| throw LogicError("Invalid encoding character '{}'", *encoding); |
| } |
| ++encoding; |
| if (*encoding != ' ') { |
| bit >>= 1; |
| } |
| } |
| return MaskValue{.mask = mask, .value = value}; |
| } |
|
|
| struct InstEncoding { |
| MaskValue mask_value; |
| Opcode opcode; |
| }; |
| constexpr std::array UNORDERED_ENCODINGS{ |
| #define INST(name, cute, encode) \ |
| InstEncoding{ \ |
| .mask_value{MaskValueFromEncoding(encode)}, \ |
| .opcode = Opcode::name, \ |
| }, |
| #include "maxwell.inc" |
| #undef INST |
| }; |
|
|
| constexpr auto SortedEncodings() { |
| std::array encodings{UNORDERED_ENCODINGS}; |
| std::ranges::sort(encodings, [](const InstEncoding& lhs, const InstEncoding& rhs) { |
| return std::popcount(lhs.mask_value.mask) > std::popcount(rhs.mask_value.mask); |
| }); |
| return encodings; |
| } |
| constexpr auto ENCODINGS{SortedEncodings()}; |
|
|
| constexpr int WidestLeftBits() { |
| int bits{64}; |
| for (const InstEncoding& encoding : ENCODINGS) { |
| bits = std::min(bits, std::countr_zero(encoding.mask_value.mask)); |
| } |
| return 64 - bits; |
| } |
| constexpr int WIDEST_LEFT_BITS{WidestLeftBits()}; |
| constexpr int MASK_SHIFT{64 - WIDEST_LEFT_BITS}; |
|
|
| constexpr size_t ToFastLookupIndex(u64 value) { |
| return static_cast<size_t>(value >> MASK_SHIFT); |
| } |
|
|
| constexpr size_t FastLookupSize() { |
| size_t max_width{}; |
| for (const InstEncoding& encoding : ENCODINGS) { |
| max_width = std::max(max_width, ToFastLookupIndex(encoding.mask_value.mask)); |
| } |
| return max_width + 1; |
| } |
| constexpr size_t FAST_LOOKUP_SIZE{FastLookupSize()}; |
|
|
| struct InstInfo { |
| [[nodiscard]] u64 Mask() const noexcept { |
| return static_cast<u64>(high_mask) << MASK_SHIFT; |
| } |
|
|
| [[nodiscard]] u64 Value() const noexcept { |
| return static_cast<u64>(high_value) << MASK_SHIFT; |
| } |
|
|
| u16 high_mask; |
| u16 high_value; |
| Opcode opcode; |
| }; |
|
|
| constexpr auto MakeFastLookupTableIndex(size_t index) { |
| std::array<InstInfo, 2> encodings{}; |
| size_t element{}; |
| for (const auto& encoding : ENCODINGS) { |
| const size_t mask{ToFastLookupIndex(encoding.mask_value.mask)}; |
| const size_t value{ToFastLookupIndex(encoding.mask_value.value)}; |
| if ((index & mask) == value) { |
| encodings.at(element) = InstInfo{ |
| .high_mask = static_cast<u16>(encoding.mask_value.mask >> MASK_SHIFT), |
| .high_value = static_cast<u16>(encoding.mask_value.value >> MASK_SHIFT), |
| .opcode = encoding.opcode, |
| }; |
| ++element; |
| } |
| } |
| return encodings; |
| } |
|
|
| auto MakeFastLookupTable() { |
| auto encodings{std::make_unique<std::array<std::array<InstInfo, 2>, FAST_LOOKUP_SIZE>>()}; |
| for (size_t index = 0; index < FAST_LOOKUP_SIZE; ++index) { |
| (*encodings)[index] = MakeFastLookupTableIndex(index); |
| } |
| return encodings; |
| } |
| const auto FAST_LOOKUP_TABLE{MakeFastLookupTable()}; |
| } |
|
|
| Opcode Decode(u64 insn) { |
| const auto& table{(*FAST_LOOKUP_TABLE)[ToFastLookupIndex(insn)]}; |
| const auto it{std::ranges::find_if( |
| table, [insn](const InstInfo& info) { return (insn & info.Mask()) == info.Value(); })}; |
| if (it == table.end()) { |
| throw NotImplementedException("Instruction 0x{:016x} is unknown / unimplemented", insn); |
| } |
| return it->opcode; |
| } |
|
|
| } |
|
|
