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Merge pull request #3518 from wwylele/hashable-struct

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Common/Hash: abstract HashableStruct from GLShader::PicaShaderConfig
This commit is contained in:
Weiyi Wang 2018-04-05 14:39:12 +03:00 committed by GitHub
parent 1fecead2ff 9c785814e7
commit acb02d300c
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GPG key ID: 4AEE18F83AFDEB23
3 changed files with 119 additions and 96 deletions
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47
src/common/hash.h
View file

@ -5,6 +5,7 @@
#pragma once
#include <cstddef>
#include <cstring>
#include "common/cityhash.h"
#include "common/common_types.h"
@ -21,16 +22,50 @@ static inline u64 ComputeHash64(const void* data, size_t len) {
}
/**
* Computes a 64-bit hash of a struct. In addition to being POD (trivially copyable and having
* standard layout), it is also critical that either the struct includes no padding, or that any
* padding is initialized to a known value by memsetting the struct to 0 before filling it in.
* Computes a 64-bit hash of a struct. In addition to being trivially copyable, it is also critical
* that either the struct includes no padding, or that any padding is initialized to a known value
* by memsetting the struct to 0 before filling it in.
*/
template <typename T>
static inline u64 ComputeStructHash64(const T& data) {
static_assert(
std::is_trivially_copyable<T>::value && std::is_standard_layout<T>::value,
"Type passed to ComputeStructHash64 must be trivially copyable and standard layout");
static_assert(std::is_trivially_copyable<T>(),
"Type passed to ComputeStructHash64 must be trivially copyable");
return ComputeHash64(&data, sizeof(data));
}
/// A helper template that ensures the padding in a struct is initialized by memsetting to 0.
template <typename T>
struct HashableStruct {
// In addition to being trivially copyable, T must also have a trivial default constructor,
// because any member initialization would be overridden by memset
static_assert(std::is_trivial<T>(), "Type passed to HashableStruct must be trivial");
/*
* We use a union because "implicitly-defined copy/move constructor for a union X copies the
* object representation of X." and "implicitly-defined copy assignment operator for a union X
* copies the object representation (3.9) of X." = Bytewise copy instead of memberwise copy.
* This is important because the padding bytes are included in the hash and comparison between
* objects.
*/
union {
T state;
};
HashableStruct() {
// Memset structure to zero padding bits, so that they will be deterministic when hashing
std::memset(&state, 0, sizeof(T));
}
bool operator==(const HashableStruct<T>& o) const {
return std::memcmp(&state, &o.state, sizeof(T)) == 0;
};
bool operator!=(const HashableStruct<T>& o) const {
return !(*this == o);
};
size_t Hash() const {
return Common::ComputeStructHash64(state);
}
};
} // namespace Common

2
src/video_core/renderer_opengl/gl_shader_gen.cpp
View file

@ -65,8 +65,6 @@ PicaShaderConfig PicaShaderConfig::BuildFromRegs(const Pica::Regs& regs) {
PicaShaderConfig res;
auto& state = res.state;
// Memset structure to zero padding bits, so that they will be deterministic when hashing
std::memset(&state, 0, sizeof(PicaShaderConfig::State));
state.scissor_test_mode = regs.rasterizer.scissor_test.mode;

166
src/video_core/renderer_opengl/gl_shader_gen.h
View file

@ -24,6 +24,82 @@ enum Attributes {
ATTRIBUTE_VIEW,
};
// NOTE: MSVC15 (Update 2) doesn't think `delete`'d constructors and operators are TC.
// This makes BitField not TC when used in a union or struct so we have to resort
// to this ugly hack.
// Once that bug is fixed we can use Pica::Regs::TevStageConfig here.
// Doesn't include const_color because we don't sync it, see comment in BuildFromRegs()
struct TevStageConfigRaw {
u32 sources_raw;
u32 modifiers_raw;
u32 ops_raw;
u32 scales_raw;
explicit operator Pica::TexturingRegs::TevStageConfig() const noexcept {
Pica::TexturingRegs::TevStageConfig stage;
stage.sources_raw = sources_raw;
stage.modifiers_raw = modifiers_raw;
stage.ops_raw = ops_raw;
stage.const_color = 0;
stage.scales_raw = scales_raw;
return stage;
}
};
struct PicaShaderConfigState {
Pica::FramebufferRegs::CompareFunc alpha_test_func;
Pica::RasterizerRegs::ScissorMode scissor_test_mode;
Pica::TexturingRegs::TextureConfig::TextureType texture0_type;
bool texture2_use_coord1;
std::array<TevStageConfigRaw, 6> tev_stages;
u8 combiner_buffer_input;
Pica::RasterizerRegs::DepthBuffering depthmap_enable;
Pica::TexturingRegs::FogMode fog_mode;
bool fog_flip;
struct {
struct {
unsigned num;
bool directional;
bool two_sided_diffuse;
bool dist_atten_enable;
bool spot_atten_enable;
bool geometric_factor_0;
bool geometric_factor_1;
} light[8];
bool enable;
unsigned src_num;
Pica::LightingRegs::LightingBumpMode bump_mode;
unsigned bump_selector;
bool bump_renorm;
bool clamp_highlights;
Pica::LightingRegs::LightingConfig config;
Pica::LightingRegs::LightingFresnelSelector fresnel_selector;
struct {
bool enable;
bool abs_input;
Pica::LightingRegs::LightingLutInput type;
float scale;
} lut_d0, lut_d1, lut_sp, lut_fr, lut_rr, lut_rg, lut_rb;
} lighting;
struct {
bool enable;
u32 coord;
Pica::TexturingRegs::ProcTexClamp u_clamp, v_clamp;
Pica::TexturingRegs::ProcTexCombiner color_combiner, alpha_combiner;
bool separate_alpha;
bool noise_enable;
Pica::TexturingRegs::ProcTexShift u_shift, v_shift;
u32 lut_width;
u32 lut_offset;
Pica::TexturingRegs::ProcTexFilter lut_filter;
} proctex;
};
/**
* This struct contains all state used to generate the GLSL shader program that emulates the current
* Pica register configuration. This struct is used as a cache key for generated GLSL shader
@ -31,13 +107,8 @@ enum Attributes {
* directly accessing Pica registers. This should reduce the risk of bugs in shader generation where
* Pica state is not being captured in the shader cache key, thereby resulting in (what should be)
* two separate shaders sharing the same key.
*
* We use a union because "implicitly-defined copy/move constructor for a union X copies the object
* representation of X." and "implicitly-defined copy assignment operator for a union X copies the
* object representation (3.9) of X." = Bytewise copy instead of memberwise copy. This is important
* because the padding bytes are included in the hash and comparison between objects.
*/
union PicaShaderConfig {
struct PicaShaderConfig : Common::HashableStruct<PicaShaderConfigState> {
/// Construct a PicaShaderConfig with the given Pica register configuration.
static PicaShaderConfig BuildFromRegs(const Pica::Regs& regs);
@ -49,87 +120,6 @@ union PicaShaderConfig {
bool TevStageUpdatesCombinerBufferAlpha(unsigned stage_index) const {
return (stage_index < 4) && ((state.combiner_buffer_input >> 4) & (1 << stage_index));
}
bool operator==(const PicaShaderConfig& o) const {
return std::memcmp(&state, &o.state, sizeof(PicaShaderConfig::State)) == 0;
};
// NOTE: MSVC15 (Update 2) doesn't think `delete`'d constructors and operators are TC.
// This makes BitField not TC when used in a union or struct so we have to resort
// to this ugly hack.
// Once that bug is fixed we can use Pica::Regs::TevStageConfig here.
// Doesn't include const_color because we don't sync it, see comment in BuildFromRegs()
struct TevStageConfigRaw {
u32 sources_raw;
u32 modifiers_raw;
u32 ops_raw;
u32 scales_raw;
explicit operator Pica::TexturingRegs::TevStageConfig() const noexcept {
Pica::TexturingRegs::TevStageConfig stage;
stage.sources_raw = sources_raw;
stage.modifiers_raw = modifiers_raw;
stage.ops_raw = ops_raw;
stage.const_color = 0;
stage.scales_raw = scales_raw;
return stage;
}
};
struct State {
Pica::FramebufferRegs::CompareFunc alpha_test_func;
Pica::RasterizerRegs::ScissorMode scissor_test_mode;
Pica::TexturingRegs::TextureConfig::TextureType texture0_type;
bool texture2_use_coord1;
std::array<TevStageConfigRaw, 6> tev_stages;
u8 combiner_buffer_input;
Pica::RasterizerRegs::DepthBuffering depthmap_enable;
Pica::TexturingRegs::FogMode fog_mode;
bool fog_flip;
struct {
struct {
unsigned num;
bool directional;
bool two_sided_diffuse;
bool dist_atten_enable;
bool spot_atten_enable;
bool geometric_factor_0;
bool geometric_factor_1;
} light[8];
bool enable;
unsigned src_num;
Pica::LightingRegs::LightingBumpMode bump_mode;
unsigned bump_selector;
bool bump_renorm;
bool clamp_highlights;
Pica::LightingRegs::LightingConfig config;
Pica::LightingRegs::LightingFresnelSelector fresnel_selector;
struct {
bool enable;
bool abs_input;
Pica::LightingRegs::LightingLutInput type;
float scale;
} lut_d0, lut_d1, lut_sp, lut_fr, lut_rr, lut_rg, lut_rb;
} lighting;
struct {
bool enable;
u32 coord;
Pica::TexturingRegs::ProcTexClamp u_clamp, v_clamp;
Pica::TexturingRegs::ProcTexCombiner color_combiner, alpha_combiner;
bool separate_alpha;
bool noise_enable;
Pica::TexturingRegs::ProcTexShift u_shift, v_shift;
u32 lut_width;
u32 lut_offset;
Pica::TexturingRegs::ProcTexFilter lut_filter;
} proctex;
} state;
};
/**
@ -152,7 +142,7 @@ namespace std {
template <>
struct hash<GLShader::PicaShaderConfig> {
size_t operator()(const GLShader::PicaShaderConfig& k) const {
return Common::ComputeStructHash64(k.state);
return k.Hash();
}
};
} // namespace std