Vulkan: Emulate subgroup ops in seamful cubemap emulation

include/GLSLANG/ShaderLang.h

@@ -26,7 +26,7 @@
 
 // Version number for shader translation API.
 // It is incremented every time the API changes.
-#define ANGLE_SH_VERSION 211
+#define ANGLE_SH_VERSION 212
 
 enum ShShaderSpec
 {
@@ -288,9 +288,14 @@ const ShCompileOptions SH_FORCE_ATOMIC_VALUE_RESOLUTION = UINT64_C(1) << 42;
 const ShCompileOptions SH_EMULATE_GL_BASE_VERTEX_BASE_INSTANCE = UINT64_C(1) << 43;
 
 // Emulate seamful cube map sampling for OpenGL ES2.0.  Currently only applies to the Vulkan
-// backend, as subgroup operations are used.  Once that dependency is broken, could be used with
+// backend, as is done after samplers are moved out of structs.  Can likely be made to work on
 // the other backends as well.
+//
+// There are two variations of this.  One using subgroup operations where available, and another
+// that emulates those operations using dFdxFine and dFdyFine.  The latter is more universally
+// available, but is buggy on Nvidia.
 const ShCompileOptions SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING = UINT64_C(1) << 44;
+const ShCompileOptions SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING_WITH_SUBGROUP_OP = UINT64_C(1) << 45;
 
 // Defines alternate strategies for implementing array index clamping.
 enum ShArrayIndexClampingStrategy

src/compiler/translator/TranslatorVulkan.cpp

@@ -645,7 +645,7 @@ void TranslatorVulkan::translate(TIntermBlock *root,
 
     sink << "#version 450 core\n";
 
-    if (compileOptions & SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING)
+    if (compileOptions & SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING_WITH_SUBGROUP_OP)
     {
         sink << "#extension GL_KHR_shader_subgroup_quad : require\n";
     }
@@ -688,10 +688,12 @@ void TranslatorVulkan::translate(TIntermBlock *root,
 
     // Rewrite samplerCubes as sampler2DArrays.  This must be done after rewriting struct samplers
     // as it doesn't expect that.
-    if (compileOptions & SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING)
+    if (compileOptions & (SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING |
+                          SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING_WITH_SUBGROUP_OP))
     {
-        RewriteCubeMapSamplersAs2DArray(root, &getSymbolTable(),
-                                        getShaderType() == GL_FRAGMENT_SHADER);
+        RewriteCubeMapSamplersAs2DArray(
+            root, &getSymbolTable(), getShaderType() == GL_FRAGMENT_SHADER,
+            compileOptions & SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING_WITH_SUBGROUP_OP);
     }
 
     if (defaultUniformCount > 0)

src/compiler/translator/tree_ops/RewriteCubeMapSamplersAs2DArray.h

@@ -19,7 +19,8 @@ class TSymbolTable;
 
 void RewriteCubeMapSamplersAs2DArray(TIntermBlock *root,
                                      TSymbolTable *symbolTable,
-                                     bool isFragmentShader);
+                                     bool isFragmentShader,
+                                     bool useSubgroupOps);
 }  // namespace sh
 
 #endif  // COMPILER_TRANSLATOR_TREEOPS_REWRITECUBEMAPSAMPLERSAS2DARRAY_H_

src/libANGLE/renderer/vulkan/ContextVk.cpp

@@ -238,6 +238,8 @@ ContextVk::ContextVk(const gl::State &state, gl::ErrorSet *errorSet, RendererVk
       mClearColorMask(kAllColorChannelsMask),
       mFlipYForCurrentSurface(false),
       mIsAnyHostVisibleBufferWritten(false),
+      mEmulateSeamfulCubeMapSampling(false),
+      mEmulateSeamfulCubeMapSamplingWithSubgroupOps(false),
       mLastCompletedQueueSerial(renderer->nextSerial()),
       mCurrentQueueSerial(renderer->nextSerial()),
       mPoolAllocator(kDefaultPoolAllocatorPageSize, 1),
@@ -441,7 +443,8 @@ angle::Result ContextVk::initialize()
         ANGLE_TRY(synchronizeCpuGpuTime());
     }
 
-    mEmulateSeamfulCubeMapSampling = shouldEmulateSeamfulCubeMapSampling();
+    mEmulateSeamfulCubeMapSampling =
+        shouldEmulateSeamfulCubeMapSampling(&mEmulateSeamfulCubeMapSamplingWithSubgroupOps);
 
     return angle::Result::Continue;
 }
@@ -2896,9 +2899,10 @@ vk::DescriptorSetLayoutDesc ContextVk::getDriverUniformsDescriptorSetDesc(
     return desc;
 }
 
-bool ContextVk::shouldEmulateSeamfulCubeMapSampling() const
+bool ContextVk::shouldEmulateSeamfulCubeMapSampling(bool *useSubgroupOpsOut) const
 {
-    if (mState.getClientMajorVersion() != 2)
+    // Only allow seamful cube map sampling in non-webgl ES2.
+    if (mState.getClientMajorVersion() != 2 || mState.isWebGL())
     {
         return false;
     }
@@ -2908,17 +2912,15 @@ bool ContextVk::shouldEmulateSeamfulCubeMapSampling() const
         return false;
     }
 
+    // Use subgroup ops where available.
     constexpr VkSubgroupFeatureFlags kSeamfulCubeMapSubgroupOperations =
         VK_SUBGROUP_FEATURE_BASIC_BIT | VK_SUBGROUP_FEATURE_BALLOT_BIT |
         VK_SUBGROUP_FEATURE_QUAD_BIT;
     const VkSubgroupFeatureFlags deviceSupportedOperations =
         mRenderer->getPhysicalDeviceSubgroupProperties().supportedOperations;
-    bool hasSeamfulCubeMapSubgroupOperations =
-        (deviceSupportedOperations & kSeamfulCubeMapSubgroupOperations) ==
-        kSeamfulCubeMapSubgroupOperations;
+    *useSubgroupOpsOut = (deviceSupportedOperations & kSeamfulCubeMapSubgroupOperations) ==
+                         kSeamfulCubeMapSubgroupOperations;
 
-    // Only enable seamful cube map emulation if the necessary subgroup operations are supported.
-    // Without them, we cannot remove derivative-related artifacts caused by helper invocations.
-    return hasSeamfulCubeMapSubgroupOperations;
+    return true;
 }
 }  // namespace rx

src/libANGLE/renderer/vulkan/ContextVk.h

@@ -313,7 +313,11 @@ class ContextVk : public ContextImpl, public vk::Context, public vk::RenderPassO
 
     void updateScissor(const gl::State &glState);
 
-    bool emulateSeamfulCubeMapSampling() const { return mEmulateSeamfulCubeMapSampling; }
+    bool emulateSeamfulCubeMapSampling(bool *useSubgroupOpsOut) const
+    {
+        *useSubgroupOpsOut = mEmulateSeamfulCubeMapSamplingWithSubgroupOps;
+        return mEmulateSeamfulCubeMapSampling;
+    }
 
   private:
     // Dirty bits.
@@ -472,7 +476,7 @@ class ContextVk : public ContextImpl, public vk::Context, public vk::RenderPassO
 
     void waitForSwapchainImageIfNecessary();
 
-    bool shouldEmulateSeamfulCubeMapSampling() const;
+    bool shouldEmulateSeamfulCubeMapSampling(bool *useSubgroupOpsOut) const;
 
     vk::PipelineHelper *mCurrentGraphicsPipeline;
     vk::PipelineAndSerial *mCurrentComputePipeline;
@@ -535,8 +539,10 @@ class ContextVk : public ContextImpl, public vk::Context, public vk::RenderPassO
     // at the end of the command buffer to make that write available to the host.
     bool mIsAnyHostVisibleBufferWritten;
 
-    // Whether this context should do seamful cube map sampling emulation.
+    // Whether this context should do seamful cube map sampling emulation, and whether subgroup
+    // operations should be used.
     bool mEmulateSeamfulCubeMapSampling;
+    bool mEmulateSeamfulCubeMapSamplingWithSubgroupOps;
 
     struct DriverUniformsDescriptorSet
     {

src/libANGLE/renderer/vulkan/GlslangWrapper.cpp

@@ -936,7 +936,7 @@ void GlslangWrapper::GetShaderSource(const gl::ProgramState &programState,
 angle::Result GlslangWrapper::GetShaderCode(vk::Context *context,
                                             const gl::Caps &glCaps,
                                             bool enableLineRasterEmulation,
-                                            bool enableSeamfulCubeMapEmulation,
+                                            bool enableSubgroupOps,
                                             const gl::ShaderMap<std::string> &shaderSources,
                                             gl::ShaderMap<std::vector<uint32_t>> *shaderCodeOut)
 {
@@ -956,20 +956,18 @@ angle::Result GlslangWrapper::GetShaderCode(vk::Context *context,
                                                kVersionDefine, kLineRasterDefine),
                        VK_ERROR_INVALID_SHADER_NV);
 
-        return GetShaderCodeImpl(context, glCaps, enableSeamfulCubeMapEmulation, patchedSources,
-                                 shaderCodeOut);
+        return GetShaderCodeImpl(context, glCaps, enableSubgroupOps, patchedSources, shaderCodeOut);
     }
     else
     {
-        return GetShaderCodeImpl(context, glCaps, enableSeamfulCubeMapEmulation, shaderSources,
-                                 shaderCodeOut);
+        return GetShaderCodeImpl(context, glCaps, enableSubgroupOps, shaderSources, shaderCodeOut);
     }
 }
 
 // static
 angle::Result GlslangWrapper::GetShaderCodeImpl(vk::Context *context,
                                                 const gl::Caps &glCaps,
-                                                bool enableSeamfulCubeMapEmulation,
+                                                bool enableSubgroupOps,
                                                 const gl::ShaderMap<std::string> &shaderSources,
                                                 gl::ShaderMap<std::vector<uint32_t>> *shaderCodeOut)
 {
@@ -1005,9 +1003,9 @@ angle::Result GlslangWrapper::GetShaderCodeImpl(vk::Context *context,
         glslang::TShader *shader = shaders[shaderType];
         shader->setStringsWithLengths(&shaderString, &shaderLength, 1);
         shader->setEntryPoint("main");
-        if (enableSeamfulCubeMapEmulation)
+        if (enableSubgroupOps)
         {
-            // Enable SPIR-V 1.3 if this workaround is used, as it uses subgroup operations.
+            // Enable SPIR-V 1.3 if to be able to use subgroup operations.
             shader->setEnvTarget(glslang::EShTargetSpv, glslang::EShTargetSpv_1_3);
         }
 

src/libANGLE/renderer/vulkan/GlslangWrapper.h

@@ -29,14 +29,14 @@ class GlslangWrapper
     static angle::Result GetShaderCode(vk::Context *context,
                                        const gl::Caps &glCaps,
                                        bool enableLineRasterEmulation,
-                                       bool enableSeamfulCubeMapEmulation,
+                                       bool enableSubgroupOps,
                                        const gl::ShaderMap<std::string> &shaderSources,
                                        gl::ShaderMap<std::vector<uint32_t>> *shaderCodesOut);
 
   private:
     static angle::Result GetShaderCodeImpl(vk::Context *context,
                                            const gl::Caps &glCaps,
-                                           bool enableSeamfulCubeMapEmulation,
+                                           bool enableSubgroupOps,
                                            const gl::ShaderMap<std::string> &shaderSources,
                                            gl::ShaderMap<std::vector<uint32_t>> *shaderCodesOut);
 };

src/libANGLE/renderer/vulkan/ProgramVk.cpp

@@ -304,10 +304,16 @@ angle::Result ProgramVk::ShaderInfo::initShaders(ContextVk *contextVk,
 {
     ASSERT(!valid());
 
+    bool useSubgroupOpsWithSeamfulCubeMapEmulation = false;
+    bool emulateSeamfulCubeMapSampling =
+        contextVk->emulateSeamfulCubeMapSampling(&useSubgroupOpsWithSeamfulCubeMapEmulation);
+    bool useSubgroupOps =
+        emulateSeamfulCubeMapSampling && useSubgroupOpsWithSeamfulCubeMapEmulation;
+
     gl::ShaderMap<std::vector<uint32_t>> shaderCodes;
-    ANGLE_TRY(GlslangWrapper::GetShaderCode(
-        contextVk, contextVk->getCaps(), enableLineRasterEmulation,
-        contextVk->emulateSeamfulCubeMapSampling(), shaderSources, &shaderCodes));
+    ANGLE_TRY(GlslangWrapper::GetShaderCode(contextVk, contextVk->getCaps(),
+                                            enableLineRasterEmulation, useSubgroupOps,
+                                            shaderSources, &shaderCodes));
 
     for (const gl::ShaderType shaderType : gl::AllShaderTypes())
     {
@@ -1437,7 +1443,8 @@ angle::Result ProgramVk::updateTexturesDescriptorSet(ContextVk *contextVk)
 
     const gl::ActiveTextureArray<vk::TextureUnit> &activeTextures = contextVk->getActiveTextures();
 
-    bool emulateSeamfulCubeMapSampling = contextVk->emulateSeamfulCubeMapSampling();
+    bool useSubgroupOps                = false;
+    bool emulateSeamfulCubeMapSampling = contextVk->emulateSeamfulCubeMapSampling(&useSubgroupOps);
 
     for (uint32_t textureIndex = 0; textureIndex < mState.getSamplerBindings().size();
          ++textureIndex)

src/libANGLE/renderer/vulkan/RendererVk.cpp

@@ -1279,6 +1279,7 @@ void RendererVk::initFeatures(const ExtensionNameList &deviceExtensionNames)
 
     if (IsWindows() && IsAMD(mPhysicalDeviceProperties.vendorID))
     {
+        // Disabled on AMD/windows due to buggy behavior.
         mFeatures.disallowSeamfulCubeMapEmulation.enabled = true;
     }
 

src/libANGLE/renderer/vulkan/ShaderVk.cpp

@@ -40,9 +40,17 @@ std::shared_ptr<WaitableCompileEvent> ShaderVk::compile(const gl::Context *conte
         compileOptions |= SH_CLAMP_POINT_SIZE;
     }
 
-    if (contextVk->emulateSeamfulCubeMapSampling())
+    bool useSubgroupOps = false;
+    if (contextVk->emulateSeamfulCubeMapSampling(&useSubgroupOps))
     {
-        compileOptions |= SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING;
+        if (useSubgroupOps)
+        {
+            compileOptions |= SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING_WITH_SUBGROUP_OP;
+        }
+        else
+        {
+            compileOptions |= SH_EMULATE_SEAMFUL_CUBE_MAP_SAMPLING;
+        }
     }
 
     return compileImpl(context, compilerInstance, mData.getSource(), compileOptions | options);

src/tests/deqp_support/deqp_gles2_test_expectations.txt

@@ -329,25 +329,6 @@
 3306 VULKAN ANDROID : dEQP-GLES2.functional.polygon_offset.fixed16_factor_1_slope = FAIL
 3307 VULKAN ANDROID : dEQP-GLES2.functional.texture.mipmap.cube.projected.nearest_linear = FAIL
 
-// Seamful cubemap sampling failures on Android (due to missing support subgroupQuad* operations).
-3243 VULKAN ANDROID : dEQP-GLES2.functional.shaders.texture_functions.vertex.texturecubelod = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.mipmap.cube.basic.linear_nearest = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.mipmap.cube.basic.linear_linear = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.mipmap.cube.projected.linear_nearest = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.mipmap.cube.projected.linear_linear = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.mipmap.cube.bias.linear_nearest = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.mipmap.cube.bias.linear_linear = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.filtering.linear_mipmap_linear_nearest_clamp = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.filtering.linear_mipmap_linear_nearest_mirror = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.filtering.linear_mipmap_linear_linear_clamp = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.filtering.linear_mipmap_linear_linear_mirror = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.wrap.clamp_clamp = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.wrap.clamp_repeat = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.wrap.clamp_mirror = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.wrap.mirror_clamp = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.wrap.mirror_repeat = FAIL
-3243 VULKAN ANDROID : dEQP-GLES2.functional.texture.vertex.cube.wrap.mirror_mirror = FAIL
-
 // These tests also fail on AMD windows driver as it is not allowed to use emulation due to errors.
 3243 VULKAN WIN AMD : dEQP-GLES2.functional.shaders.texture_functions.vertex.texturecubelod = FAIL
 3243 VULKAN WIN AMD : dEQP-GLES2.functional.texture.mipmap.cube.basic.linear_nearest = FAIL