Implement glsl atomic's [non image or memory scope] with optional extension(s); resolves #3587 for GLSL & SPIR-V targets (#3755)

The following commit implements atomic operations & types associated with OpenGL 4.6, GL_EXT_vulkan_glsl_relaxed, GLSL_EXT_shader_atomic_float, GLSL_EXT_shader_atomic_float2, for GLSL & SPIR-V targets.

Fully implements all functions, and built-in type's, resolves https://github.com/shader-slang/slang/issues/3560 for GLSL & SPRI-V targets.

[Atomic extensions for GLSL can be found here](https://github.com/KhronosGroup/GLSL/tree/main)

Notes of worth:

* atomic_uint is well defined in GLSL->OpenGL, although was removed in GLSL->VK unless a compiler extension is supported (GL_EXT_vulkan_glsl_relaxed). This support entails transforming all atomic_uint operations and references into a storage buffer. SPIR-V has AtomicCounter+AtomicStorage (atomic_uint parallel) but does not implement these capabilities for SPIR-V->VK in any scenario. Due to the case we transform atomic_uint ourselves (GLSL_Syntax->Slang_IR) to accommodate transforming atomic_uint into valid syntax.
* GLSL_EXT_shader_atomic_float2 (all float16_t & some float/double operations) support is minimal and worth watching out for if enabling the tests. 

2 files changed, 39 insertions, 14 deletions

diff --git a/tools/gfx/vulkan/vk-api.h b/tools/gfx/vulkan/vk-api.h
index f7523eb7f..27a19acfb 100644
--- a/tools/gfx/vulkan/vk-api.h
+++ b/tools/gfx/vulkan/vk-api.h
@@ -241,32 +241,43 @@ struct VulkanExtendedFeatureProperties
 {
     // 16 bit storage features
     VkPhysicalDevice16BitStorageFeatures storage16BitFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_16BIT_STORAGE_FEATURES_KHR};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_16BIT_STORAGE_FEATURES_KHR
+    };
     // Atomic Float features
     VkPhysicalDeviceShaderAtomicFloatFeaturesEXT atomicFloatFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_ATOMIC_FLOAT_FEATURES_EXT};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_ATOMIC_FLOAT_FEATURES_EXT
+    };
+    VkPhysicalDeviceShaderAtomicFloat2FeaturesEXT atomicFloat2Features = {
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_ATOMIC_FLOAT_2_FEATURES_EXT
+    };
     // Extended dynamic state features
     VkPhysicalDeviceExtendedDynamicStateFeaturesEXT extendedDynamicStateFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_EXTENDED_DYNAMIC_STATE_FEATURES_EXT};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_EXTENDED_DYNAMIC_STATE_FEATURES_EXT
+    };
     // Acceleration structure features
     VkPhysicalDeviceAccelerationStructureFeaturesKHR accelerationStructureFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ACCELERATION_STRUCTURE_FEATURES_KHR};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ACCELERATION_STRUCTURE_FEATURES_KHR
+    };
     // Ray tracing pipeline features
     VkPhysicalDeviceRayTracingPipelineFeaturesKHR rayTracingPipelineFeatures = {
         VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_RAY_TRACING_PIPELINE_FEATURES_KHR
     };
     // Ray query (inline ray-tracing) features
     VkPhysicalDeviceRayQueryFeaturesKHR rayQueryFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_RAY_QUERY_FEATURES_KHR};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_RAY_QUERY_FEATURES_KHR
+    };
     // Inline uniform block features
     VkPhysicalDeviceInlineUniformBlockFeaturesEXT inlineUniformBlockFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_INLINE_UNIFORM_BLOCK_FEATURES_EXT};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_INLINE_UNIFORM_BLOCK_FEATURES_EXT
+    };
     // Robustness2 features
     VkPhysicalDeviceRobustness2FeaturesEXT robustness2Features = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ROBUSTNESS_2_FEATURES_EXT};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ROBUSTNESS_2_FEATURES_EXT
+    };
 
     VkPhysicalDeviceRayTracingInvocationReorderFeaturesNV rayTracingInvocationReorderFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_RAY_TRACING_INVOCATION_REORDER_FEATURES_NV};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_RAY_TRACING_INVOCATION_REORDER_FEATURES_NV
+    };
 
     // Clock features
     VkPhysicalDeviceShaderClockFeaturesKHR clockFeatures = { 
@@ -280,15 +291,18 @@ struct VulkanExtendedFeatureProperties
 
     // Multiview features
     VkPhysicalDeviceMultiviewFeaturesKHR multiviewFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MULTIVIEW_FEATURES_KHR };
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MULTIVIEW_FEATURES_KHR 
+    };
 
     // Fragment shading rate features
     VkPhysicalDeviceFragmentShadingRateFeaturesKHR fragmentShadingRateFeatures = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FRAGMENT_SHADING_RATE_FEATURES_KHR };
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FRAGMENT_SHADING_RATE_FEATURES_KHR 
+    };
 
     // Vulkan 1.2 features.
     VkPhysicalDeviceVulkan12Features vulkan12Features = {
-        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_2_FEATURES};
+        VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_2_FEATURES
+    };
 };
 
 struct VulkanApi
diff --git a/tools/gfx/vulkan/vk-device.cpp b/tools/gfx/vulkan/vk-device.cpp
index 2a914b86b..1b046d8f2 100644
--- a/tools/gfx/vulkan/vk-device.cpp
+++ b/tools/gfx/vulkan/vk-device.cpp
@@ -476,13 +476,17 @@ Result DeviceImpl::initVulkanInstanceAndDevice(
         extendedFeatures.clockFeatures.pNext = deviceFeatures2.pNext;
         deviceFeatures2.pNext = &extendedFeatures.clockFeatures;
 
-        // Atomic Float
+        // Atomic Float 
         // To detect atomic float we need
         // https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VkPhysicalDeviceShaderAtomicFloatFeaturesEXT.html
 
         extendedFeatures.atomicFloatFeatures.pNext = deviceFeatures2.pNext;
         deviceFeatures2.pNext = &extendedFeatures.atomicFloatFeatures;
 
+        // https://registry.khronos.org/vulkan/specs/1.3-extensions/man/html/VkPhysicalDeviceShaderAtomicFloat2FeaturesEXT.html
+        extendedFeatures.atomicFloat2Features.pNext = deviceFeatures2.pNext;
+        deviceFeatures2.pNext = &extendedFeatures.atomicFloat2Features;
+
         // mesh shader features
         extendedFeatures.meshShaderFeatures.pNext = deviceFeatures2.pNext;
         deviceFeatures2.pNext = &extendedFeatures.meshShaderFeatures;
@@ -543,7 +547,7 @@ Result DeviceImpl::initVulkanInstanceAndDevice(
         // SIMPLE_EXTENSION_FEATURE(struct, feature member name, extension
         // name, features...) will check for the presence of the boolean
         // feature member in struct and the availability of the extensions. If
-        // they are both present then the extensions are addded, the struct
+        // they are both present then the extensions are added, the struct
         // linked into the deviceCreateInfo chain and the features added to the
         // supported features list.
 #define SIMPLE_EXTENSION_FEATURE(s, m, e, ...) \
@@ -563,12 +567,19 @@ Result DeviceImpl::initVulkanInstanceAndDevice(
 
         SIMPLE_EXTENSION_FEATURE(
             extendedFeatures.atomicFloatFeatures,
-            shaderBufferFloat32AtomicAdd,
+            shaderBufferFloat32Atomics,
             VK_EXT_SHADER_ATOMIC_FLOAT_EXTENSION_NAME,
             "atomic-float"
         );
 
         SIMPLE_EXTENSION_FEATURE(
+            extendedFeatures.atomicFloat2Features,
+            shaderBufferFloat16Atomics,
+            VK_EXT_SHADER_ATOMIC_FLOAT_2_EXTENSION_NAME,
+            "atomic-float-2"
+        );
+
+        SIMPLE_EXTENSION_FEATURE(
             extendedFeatures.extendedDynamicStateFeatures,
             extendedDynamicState,
             VK_EXT_EXTENDED_DYNAMIC_STATE_EXTENSION_NAME,