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[Perf] (MG_Backend): key DirectVulkan's pipeline memo on state values, not a version that never repeats

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Two per-draw churn costs, one cause each.

A blend toggle switched pipelines through a memo keyed on a monotonic
pipeline-state version - which never repeats, so flipping GL_BLEND off and back
on produced a "new" key both times, forced the full SetupDraw and rebuilt the
whole pipeline payload for a pipeline the cache already held. The memo now keys
on a value hash of the pipeline-relevant fixed-function state, recomputed only
when the state version moved, and the consecutive-draw fast path re-resolves
just the pipeline through it when nothing but render state changed. Blaze3D
brackets every batch with exactly this toggle; mc_state_toggle drops 36%
(6629 -> 4230 ns/op, 4.8x native to 3.7x).

The sampler-churn cost had the same shape as the Espryt side fixed separately:
glBindSampler bumps the frontend texture-bind generation even when it re-binds
the sampler the unit already holds, so the per-draw fast path died every draw.
The fast path now proves each binding's descriptor inputs unchanged - texture
and sampler lifetime ids, parameter and content sums, the sampling-resolution
generation, image epochs and exact layouts - and reuses the binding's cached
VkDescriptorImageInfo instead of re-running the resolve chain.
mc_sampler_churn drops 30% (1597 -> 1125), and the proof machinery pays for
itself on the uniform-range case too (-17%).

mc_tex_param stays where it is on this backend deliberately: profiling shows its
remaining cost is frontend validation with zero backend work, unreachable from
Renderer/.

All nine cases measured on both backends, interleaved A/B, no case worse than
noise. Unit tests 421/421.
This commit is contained in:
BZLZHH
2026-08-06 11:21:26 -04:00
parent 9be5d95440
commit 4b3fd11462
4 changed files with 378 additions and 43 deletions
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MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.h
+47 -3
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@@ -53,18 +53,42 @@ namespace MobileGL::MG_Backend::DirectVulkan {
// caches - a live layout's entry must never be purged (its sets would be
// unreachable pool slots), so there is deliberately no age-based sweep here.
void OnDescriptorSetLayoutDestroyed(VkDescriptorSetLayout descriptorSetLayout);
// One record per visited CombinedImageSampler binding (post fallback substitution,
// in binding order): the resolved texture and effective sampler, as never-reused
// lifetime ids so a freed-and-reallocated object at the same heap address can only
// MISS a comparison, never false-hit it (same ABA rule as SamplerResolveMemo).
struct SampledBindingRecord {
Uint64 textureLifetimeId = 0;
Uint64 samplerLifetimeId = 0;
};
Bool CollectSampledTextures(const MG_State::GLState::ProgramObject& program,
const ProgramFactory::VkProgramObject& programObj,
Vector<MG_State::GLState::ITextureObject*>& outTextures);
Vector<MG_State::GLState::ITextureObject*>& outTextures,
Vector<SampledBindingRecord>* outBindingRecords = nullptr);
// Shadow-compare for the SetupDraw fast path: re-runs the CollectSampledTextures
// walk and reports whether every visited binding still resolves to the recorded
// (texture, effective sampler) pair. A texture bind generation bump alone (e.g. a
// redundant glBindSampler, which always bumps it) does not prove the sampled set
// moved; this walk does, without rebuilding the set or falling off the fast path.
Bool SampledBindingsUnchanged(const MG_State::GLState::ProgramObject& program,
const ProgramFactory::VkProgramObject& programObj,
const Vector<SampledBindingRecord>& previousRecords) const;
Bool CollectStorageImageTextures(const MG_State::GLState::ProgramObject& program,
const ProgramFactory::VkProgramObject& programObj,
Vector<MG_State::GLState::ITextureObject*>& outTextures) const;
// samplerDescriptorsUnchangedHint: the caller (SetupDraw fast path) proved that
// every input of every combined-image-sampler resolution is unchanged since the
// previous draw's resolve - same (texture, sampler) per binding, texture params
// sum, sampling-resolution generation (sampler params + texture shape), image
// epochs AND per-resource layout values - so the per-binding cached
// VkDescriptorImageInfo may be reused without re-running the resolve chain.
Bool BindProgramUniformBuffers(VkCommandBuffer commandBuffer,
const MG_State::GLState::ProgramObject& program,
const ProgramFactory::VkProgramObject& programObj,
Uint32 frameIndex,
VkPipelineBindPoint bindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS,
const SamplerBindingOverride* samplerBindingOverride = nullptr);
const SamplerBindingOverride* samplerBindingOverride = nullptr,
Bool samplerDescriptorsUnchangedHint = false);
// Pure format-policy helper kept public for host regression tests. Formatted storage
// images use their shader qualifier; transformed float images use glBindImageTexture's
@@ -114,6 +138,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
static Bool ResolveSamplerTexture(const MG_State::GLState::ProgramObject& program,
const ProgramFactory::VkProgramObject& programObj, Uint32 binding,
SharedPtr<MG_State::GLState::ITextureObject>& outTexture);
// Shared per-binding resolution for CollectSampledTextures and
// SampledBindingsUnchanged, so membership and comparison can never diverge:
// texture after the fallback substitution (may still be null when no fallback
// exists), effective sampler = unit override else the texture's own sampler.
// False = the binding is skipped (unbound with a non-2D fallback target).
Bool ResolveSampledBinding(const MG_State::GLState::ProgramObject& program,
const ProgramFactory::VkProgramObject& programObj, Uint32 binding,
MG_State::GLState::ITextureObject*& outTexture,
const MG_State::GLState::SamplerObject*& outSampler) const;
// Raw-pointer variant for the per-draw sampled-texture walk (CollectSampledTextures):
// the bound texture stays alive through the draw via GL binding state, so callers that
// only need the pointer skip the SharedPtr copy's atomic refcount churn.
@@ -121,9 +154,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
const MG_State::GLState::ProgramObject& program,
const ProgramFactory::VkProgramObject& programObj, Uint32 binding);
SharedPtr<MG_State::GLState::ITextureObject> GetFallbackTexture(TextureTarget target) const;
// trustUnchangedHint: reuse this binding's cached VkDescriptorImageInfo outright
// (see BindProgramUniformBuffers' samplerDescriptorsUnchangedHint for the proof
// obligations the caller carries).
Bool ResolveSamplerDescriptor(VkCommandBuffer commandBuffer, const MG_State::GLState::ProgramObject& program,
const ProgramFactory::VkProgramObject& programObj, Uint32 binding,
VkDescriptorImageInfo& outImageInfo) const;
VkDescriptorImageInfo& outImageInfo,
Bool trustUnchangedHint = false) const;
Bool ResolveSamplerDescriptorOverride(const SamplerBindingOverride& samplerBindingOverride,
VkDescriptorImageInfo& outImageInfo) const;
Bool ResolveTexelBufferDescriptor(const MG_State::GLState::ProgramObject& program,
@@ -253,6 +290,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
SamplerNumericDomain viewFormatDomain = SamplerNumericDomain::Unknown;
VkFormat viewFormat = VK_FORMAT_UNDEFINED;
Bool viewFormatValid = false;
// Whole resolved descriptor from this binding's last full resolve. Reused
// ONLY under ResolveSamplerDescriptor's trustUnchangedHint, whose caller
// proves every resolve input unchanged; cleared with the per-frame reset
// (the cached VkSampler outlives a frame only via a fresh resolve, which
// also re-stamps it against VkSamplerManager's frame-boundary sweep).
VkDescriptorImageInfo info{};
Bool infoValid = false;
};
mutable Vector<SamplerResolveMemo> m_samplerResolveMemo;
};