Vulkan: Track valid descriptor set layouts

Instead of looping through kMaxDescriptorSetLayoutBindings in
`DescriptorSetLayoutDesc::unpackBindings` track valid descriptor set
layouts in `DescriptorSetLayoutDesc::update`

Bug: angleproject:2462
Change-Id: I1ca2ba72875d9306b6059b14cde39c5d16250be6
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5464160
Reviewed-by: Charlie Lao <cclao@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: mohan maiya <m.maiya@samsung.com>

2 files changed, 16 insertions, 6 deletions

diff --git a/src/libANGLE/renderer/vulkan/vk_cache_utils.cpp b/src/libANGLE/renderer/vulkan/vk_cache_utils.cpp
index 4680ccfb81..ff2e4259f8 100644
--- a/src/libANGLE/renderer/vulkan/vk_cache_utils.cpp
+++ b/src/libANGLE/renderer/vulkan/vk_cache_utils.cpp
@@ -4294,7 +4294,9 @@ bool operator==(const AttachmentOpsArray &lhs, const AttachmentOpsArray &rhs)
 }
 
 // DescriptorSetLayoutDesc implementation.
-DescriptorSetLayoutDesc::DescriptorSetLayoutDesc() : mPackedDescriptorSetLayout{} {}
+DescriptorSetLayoutDesc::DescriptorSetLayoutDesc()
+    : mPackedDescriptorSetLayout{}, mValidDescriptorSetLayoutIndexMask()
+{}
 
 DescriptorSetLayoutDesc::~DescriptorSetLayoutDesc() = default;
 
@@ -4336,19 +4338,20 @@ void DescriptorSetLayoutDesc::update(uint32_t bindingIndex,
         ASSERT(count == 1);
         packedBinding.immutableSampler = immutableSampler->getHandle();
     }
+
+    mValidDescriptorSetLayoutIndexMask.set(bindingIndex, count > 0);
 }
 
 void DescriptorSetLayoutDesc::unpackBindings(DescriptorSetLayoutBindingVector *bindings,
                                              std::vector<VkSampler> *immutableSamplers) const
 {
-    for (uint32_t bindingIndex = 0; bindingIndex < kMaxDescriptorSetLayoutBindings; ++bindingIndex)
+    for (size_t bindingIndex : mValidDescriptorSetLayoutIndexMask)
     {
         const PackedDescriptorSetBinding &packedBinding = mPackedDescriptorSetLayout[bindingIndex];
-        if (packedBinding.count == 0)
-            continue;
+        ASSERT(packedBinding.count != 0);
 
         VkDescriptorSetLayoutBinding binding = {};
-        binding.binding                      = bindingIndex;
+        binding.binding                      = static_cast<uint32_t>(bindingIndex);
         binding.descriptorCount              = packedBinding.count;
         binding.descriptorType               = static_cast<VkDescriptorType>(packedBinding.type);
         binding.stageFlags = static_cast<VkShaderStageFlags>(packedBinding.stages);
diff --git a/src/libANGLE/renderer/vulkan/vk_cache_utils.h b/src/libANGLE/renderer/vulkan/vk_cache_utils.h
index b1d70bfdaf..056d350503 100644
--- a/src/libANGLE/renderer/vulkan/vk_cache_utils.h
+++ b/src/libANGLE/renderer/vulkan/vk_cache_utils.h
@@ -993,6 +993,11 @@ constexpr uint32_t kMaxDescriptorSetLayoutBindings =
 using DescriptorSetLayoutBindingVector =
     angle::FixedVector<VkDescriptorSetLayoutBinding, kMaxDescriptorSetLayoutBindings>;
 
+// Technically this needs to only be kMaxDescriptorSetLayoutBindings but due to struct padding
+// issues round up size to 64.
+constexpr uint32_t kMaxDescriptorSetLayoutCount = roundUpPow2(kMaxDescriptorSetLayoutBindings, 64u);
+using DescriptorSetLayoutIndexMask              = angle::BitSet<kMaxDescriptorSetLayoutCount>;
+
 // A packed description of a descriptor set layout. Use similarly to RenderPassDesc and
 // GraphicsPipelineDesc. Currently we only need to differentiate layouts based on sampler and ubo
 // usage. In the future we could generalize this.
@@ -1016,7 +1021,7 @@ class DescriptorSetLayoutDesc final
     void unpackBindings(DescriptorSetLayoutBindingVector *bindings,
                         std::vector<VkSampler> *immutableSamplers) const;
 
-    bool empty() const { return *this == DescriptorSetLayoutDesc(); }
+    bool empty() const { return !mValidDescriptorSetLayoutIndexMask.any(); }
 
   private:
     // There is a small risk of an issue if the sampler cache is evicted but not the descriptor
@@ -1037,6 +1042,8 @@ class DescriptorSetLayoutDesc final
     // This is a compact representation of a descriptor set layout.
     std::array<PackedDescriptorSetBinding, kMaxDescriptorSetLayoutBindings>
         mPackedDescriptorSetLayout;
+
+    DescriptorSetLayoutIndexMask mValidDescriptorSetLayoutIndexMask;
 };
 
 // The following are for caching descriptor set layouts. Limited to max three descriptor set