Add feature for subgroup ballot in fragment and compute shaders

gfx-rs · Sep 30, 2023 · 414f844 · 414f844
1 parent 9a76c48
commit 414f844
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Showing 3 changed files with 35 additions and 2 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -90,6 +90,7 @@ By @wumpf in [#4147](https://github.com/gfx-rs/wgpu/pull/4147)
 
 - Add `gles_minor_version` field to `wgpu::InstanceDescriptor`. By @PJB3005 in [#3998](https://github.com/gfx-rs/wgpu/pull/3998)
 - Re-export Naga. By @exrook in [#4172](https://github.com/gfx-rs/wgpu/pull/4172)
+- Subgroup feature. By @exrook in [#4189](https://github.com/gfx-rs/wgpu/pull/4189)
 
 ### Changes
 

diff --git a/wgpu-hal/src/vulkan/adapter.rs b/wgpu-hal/src/vulkan/adapter.rs
@@ -488,6 +488,18 @@ impl PhysicalDeviceFeatures {
             );
         }
 
+        if let Some(ref subgroup) = caps.subgroup {
+            features.set(
+                F::SUBGROUP_BALLOT,
+                subgroup
+                    .supported_operations
+                    .contains(vk::SubgroupFeatureFlags::BALLOT)
+                    && subgroup
+                        .supported_stages
+                        .contains(vk::ShaderStageFlags::COMPUTE | vk::ShaderStageFlags::FRAGMENT),
+            );
+        }
+
         let supports_depth_format = |format| {
             supports_format(
                 instance,
@@ -545,6 +557,7 @@ pub struct PhysicalDeviceCapabilities {
     maintenance_3: Option<vk::PhysicalDeviceMaintenance3Properties>,
     descriptor_indexing: Option<vk::PhysicalDeviceDescriptorIndexingPropertiesEXT>,
     driver: Option<vk::PhysicalDeviceDriverPropertiesKHR>,
+    subgroup: Option<vk::PhysicalDeviceSubgroupProperties>,
     /// The effective driver api version supported by the physical device.
     ///
     /// The Vulkan specification states the following in the documentation for VkPhysicalDeviceProperties:
@@ -815,6 +828,13 @@ impl super::InstanceShared {
                     builder = builder.push_next(next);
                 }
 
+                if self.driver_api_version >= vk::API_VERSION_1_1 {
+                    let next = capabilities
+                        .subgroup
+                        .insert(vk::PhysicalDeviceSubgroupProperties::default());
+                    builder = builder.push_next(next);
+                }
+
                 let mut properties2 = builder.build();
                 unsafe {
                     get_device_properties.get_physical_device_properties2(phd, &mut properties2);
@@ -1247,6 +1267,10 @@ impl super::Adapter {
                 capabilities.push(spv::Capability::Geometry);
             }
 
+            if features.contains(wgt::Features::SUBGROUP_BALLOT) {
+                capabilities.push(spv::Capability::GroupNonUniformBallot);
+            }
+
             if features.intersects(
                 wgt::Features::SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING
                     | wgt::Features::UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING,
@@ -1271,7 +1295,7 @@ impl super::Adapter {
                 true, // could check `super::Workarounds::SEPARATE_ENTRY_POINTS`
             );
             spv::Options {
-                lang_version: (1, 0),
+                lang_version: (1, 3),
                 flags,
                 capabilities: Some(capabilities.iter().cloned().collect()),
                 bounds_check_policies: naga::proc::BoundsCheckPolicies {

diff --git a/wgpu-types/src/lib.rs b/wgpu-types/src/lib.rs
@@ -299,7 +299,15 @@ bitflags::bitflags! {
         /// This is a web and native feature.
         const SHADER_F16 = 1 << 8;
 
-        // 9..14 available
+        /// Allows shaders to use the subgroup opteraion built-ins
+        ///
+        /// Supported Platforms:
+        /// - Vulkan
+        ///
+        /// This is a web and native feature.
+        const SUBGROUP_BALLOT = 1 << 9;
+
+        // 10..14 available
 
         // Texture Formats: