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fixed_pipeline_state: Hash and compare the whole structure

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Pad FixedPipelineState's size to 384 bytes to be a multiple of 16.

Compare the whole struct with std::memcmp and hash with CityHash. Using
CityHash instead of a naive hash should reduce the number of collisions.
Improve used type traits to ensure this operation is safe.

With these changes the improvements to the hashable pipeline state are:

Optimized structure
Hash:            89 ns
Comparison:     103 ns
Construction*:  164 ns
Struct size:    384 bytes

Original structure
Hash:           148 ns
Equal:          174 ns
Construction*:  281 ns
Size:          1384 bytes

* Attribute state initialization is not measured

These measures are averages taken with std::chrono::high_accuracy_clock
on MSVC shipped on Visual Studio 16.6.0 Preview 2.1.
This commit is contained in:
ReinUsesLisp 2020-04-18 05:55:49 -03:00
parent b571c92dfd
commit d62f57cf5a
2 changed files with 9 additions and 105 deletions
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60
src/video_core/renderer_vulkan/fixed_pipeline_state.cpp
View file

@ -140,66 +140,13 @@ void FixedPipelineState::BlendingAttachment::Fill(const Maxwell& regs, std::size
enable.Assign(1);
}
std::size_t FixedPipelineState::BlendingAttachment::Hash() const noexcept {
return raw;
}
bool FixedPipelineState::BlendingAttachment::operator==(const BlendingAttachment& rhs) const
noexcept {
return raw == rhs.raw;
}
std::size_t FixedPipelineState::VertexInput::Hash() const noexcept {
// TODO(Rodrigo): Replace this
return Common::CityHash64(reinterpret_cast<const char*>(this), sizeof *this);
}
bool FixedPipelineState::VertexInput::operator==(const VertexInput& rhs) const noexcept {
return std::memcmp(this, &rhs, sizeof *this) == 0;
}
std::size_t FixedPipelineState::Rasterizer::Hash() const noexcept {
u64 hash = static_cast<u64>(raw) << 32;
std::memcpy(&hash, &point_size, sizeof(u32));
std::size_t FixedPipelineState::Hash() const noexcept {
const u64 hash = Common::CityHash64(reinterpret_cast<const char*>(this), sizeof *this);
return static_cast<std::size_t>(hash);
}
bool FixedPipelineState::Rasterizer::operator==(const Rasterizer& rhs) const noexcept {
return raw == rhs.raw && point_size == rhs.point_size;
}
std::size_t FixedPipelineState::DepthStencil::Hash() const noexcept {
return raw;
}
bool FixedPipelineState::DepthStencil::operator==(const DepthStencil& rhs) const noexcept {
return raw == rhs.raw;
}
std::size_t FixedPipelineState::ColorBlending::Hash() const noexcept {
std::size_t hash = 0;
for (std::size_t rt = 0; rt < std::size(attachments); ++rt) {
boost::hash_combine(hash, attachments[rt].Hash());
}
return hash;
}
bool FixedPipelineState::ColorBlending::operator==(const ColorBlending& rhs) const noexcept {
return attachments == rhs.attachments;
}
std::size_t FixedPipelineState::Hash() const noexcept {
std::size_t hash = 0;
boost::hash_combine(hash, vertex_input.Hash());
boost::hash_combine(hash, rasterizer.Hash());
boost::hash_combine(hash, depth_stencil.Hash());
boost::hash_combine(hash, color_blending.Hash());
return hash;
}
bool FixedPipelineState::operator==(const FixedPipelineState& rhs) const noexcept {
return std::tie(vertex_input, rasterizer, depth_stencil, color_blending) ==
std::tie(rhs.vertex_input, rhs.rasterizer, rhs.depth_stencil, rhs.color_blending);
return std::memcmp(this, &rhs, sizeof *this) == 0;
}
FixedPipelineState GetFixedPipelineState(const Maxwell& regs) {
@ -207,6 +154,7 @@ FixedPipelineState GetFixedPipelineState(const Maxwell& regs) {
fixed_state.rasterizer.Fill(regs);
fixed_state.depth_stencil.Fill(regs);
fixed_state.color_blending.Fill(regs);
fixed_state.padding = {};
return fixed_state;
}

54
src/video_core/renderer_vulkan/fixed_pipeline_state.h
View file

@ -17,13 +17,7 @@ namespace Vulkan {
using Maxwell = Tegra::Engines::Maxwell3D::Regs;
// TODO(Rodrigo): Optimize this structure.
template <class T>
inline constexpr bool IsHashable = std::has_unique_object_representations_v<T>&&
std::is_trivially_copyable_v<T>&& std::is_trivially_constructible_v<T>;
struct FixedPipelineState {
struct alignas(32) FixedPipelineState {
static u32 PackComparisonOp(Maxwell::ComparisonOp op) noexcept;
static Maxwell::ComparisonOp UnpackComparisonOp(u32 packed) noexcept;
@ -102,7 +96,6 @@ struct FixedPipelineState {
return UnpackBlendFactor(factor_dest_a.Value());
}
};
static_assert(IsHashable<BlendingAttachment>);
struct VertexInput {
union Binding {
@ -151,16 +144,7 @@ struct FixedPipelineState {
attribute.type.Assign(static_cast<u32>(type));
attribute.size.Assign(static_cast<u32>(size));
}
std::size_t Hash() const noexcept;
bool operator==(const VertexInput& rhs) const noexcept;
bool operator!=(const VertexInput& rhs) const noexcept {
return !operator==(rhs);
}
};
static_assert(IsHashable<VertexInput>);
struct Rasterizer {
union {
@ -187,14 +171,6 @@ struct FixedPipelineState {
void Fill(const Maxwell& regs) noexcept;
std::size_t Hash() const noexcept;
bool operator==(const Rasterizer& rhs) const noexcept;
bool operator!=(const Rasterizer& rhs) const noexcept {
return !operator==(rhs);
}
constexpr Maxwell::PrimitiveTopology Topology() const noexcept {
return static_cast<Maxwell::PrimitiveTopology>(topology.Value());
}
@ -207,7 +183,6 @@ struct FixedPipelineState {
return UnpackFrontFace(front_face.Value());
}
};
static_assert(IsHashable<Rasterizer>);
struct DepthStencil {
template <std::size_t Position>
@ -247,39 +222,22 @@ struct FixedPipelineState {
void Fill(const Maxwell& regs) noexcept;
std::size_t Hash() const noexcept;
bool operator==(const DepthStencil& rhs) const noexcept;
bool operator!=(const DepthStencil& rhs) const noexcept {
return !operator==(rhs);
}
Maxwell::ComparisonOp DepthTestFunc() const noexcept {
return UnpackComparisonOp(depth_test_func);
}
};
static_assert(IsHashable<DepthStencil>);
struct ColorBlending {
std::array<BlendingAttachment, Maxwell::NumRenderTargets> attachments;
void Fill(const Maxwell& regs) noexcept;
std::size_t Hash() const noexcept;
bool operator==(const ColorBlending& rhs) const noexcept;
bool operator!=(const ColorBlending& rhs) const noexcept {
return !operator==(rhs);
}
};
static_assert(IsHashable<ColorBlending>);
VertexInput vertex_input;
Rasterizer rasterizer;
DepthStencil depth_stencil;
ColorBlending color_blending;
std::array<u8, 20> padding;
std::size_t Hash() const noexcept;
@ -289,12 +247,10 @@ struct FixedPipelineState {
return !operator==(rhs);
}
};
static_assert(std::is_trivially_copyable_v<FixedPipelineState::BlendingAttachment>);
static_assert(std::is_trivially_copyable_v<FixedPipelineState::VertexInput>);
static_assert(std::is_trivially_copyable_v<FixedPipelineState::Rasterizer>);
static_assert(std::is_trivially_copyable_v<FixedPipelineState::DepthStencil>);
static_assert(std::is_trivially_copyable_v<FixedPipelineState::ColorBlending>);
static_assert(std::has_unique_object_representations_v<FixedPipelineState>);
static_assert(std::is_trivially_copyable_v<FixedPipelineState>);
static_assert(std::is_trivially_constructible_v<FixedPipelineState>);
static_assert(sizeof(FixedPipelineState) % 32 == 0, "Size is not aligned");
FixedPipelineState GetFixedPipelineState(const Maxwell& regs);