Implement GL_EXT_fragment_invocation_density

SPIRV/GLSL.ext.EXT.h

@@ -28,10 +28,11 @@
 #define GLSLextEXT_H
 
 static const int GLSLextEXTVersion = 100;
-static const int GLSLextEXTRevision = 1;
+static const int GLSLextEXTRevision = 2;
 
 static const char* const E_SPV_EXT_shader_stencil_export        = "SPV_EXT_shader_stencil_export";
 static const char* const E_SPV_EXT_shader_viewport_index_layer  = "SPV_EXT_shader_viewport_index_layer";
 static const char* const E_SPV_EXT_fragment_fully_covered = "SPV_EXT_fragment_fully_covered";
+static const char* const E_SPV_EXT_fragment_invocation_density = "SPV_EXT_fragment_invocation_density";
 
 #endif  // #ifndef GLSLextEXT_H

SPIRV/GlslangToSpv.cpp

@@ -833,6 +833,16 @@ spv::BuiltIn TGlslangToSpvTraverser::TranslateBuiltInDecoration(glslang::TBuiltI
         builder.addCapability(spv::CapabilityMultiView);
         return spv::BuiltInViewIndex;
 
+    case glslang::EbvFragSizeEXT:
+        builder.addExtension(spv::E_SPV_EXT_fragment_invocation_density);
+        builder.addCapability(spv::CapabilityFragmentDensityEXT);
+        return spv::BuiltInFragSizeEXT;
+
+    case glslang::EbvFragInvocationCountEXT:
+        builder.addExtension(spv::E_SPV_EXT_fragment_invocation_density);
+        builder.addCapability(spv::CapabilityFragmentDensityEXT);
+        return spv::BuiltInFragInvocationCountEXT;
+
 #ifdef NV_EXTENSIONS
     case glslang::EbvViewportMaskNV:
         if (!memberDeclaration) {

SPIRV/doc.cpp

@@ -388,12 +388,15 @@ const char* BuiltInString(int builtIn)
     case BuiltInSecondaryViewportMaskNV:    return "SecondaryViewportMaskNV";
     case BuiltInPositionPerViewNV:          return "PositionPerViewNV";
     case BuiltInViewportMaskPerViewNV:      return "ViewportMaskPerViewNV";
-    case BuiltInFragmentSizeNV:             return "FragmentSizeNV";
-    case BuiltInInvocationsPerPixelNV:      return "InvocationsPerPixelNV";
+//    case BuiltInFragmentSizeNV:             return "FragmentSizeNV";        // superseded by BuiltInFragSizeEXT
+//    case BuiltInInvocationsPerPixelNV:      return "InvocationsPerPixelNV"; // superseded by BuiltInFragInvocationCountEXT
     case BuiltInBaryCoordNV:                return "BaryCoordNV";
     case BuiltInBaryCoordNoPerspNV:         return "BaryCoordNoPerspNV";
 #endif
 
+    case BuiltInFragSizeEXT:                return "FragSizeEXT";
+    case BuiltInFragInvocationCountEXT:     return "FragInvocationCountEXT";
+
     case 5264: return "FullyCoveredEXT";
 
 
@@ -897,8 +900,9 @@ const char* CapabilityString(int info)
     case CapabilityComputeDerivativeGroupLinearNV:  return "ComputeDerivativeGroupLinearNV";
     case CapabilityFragmentBarycentricNV:           return "FragmentBarycentricNV";
     case CapabilityMeshShadingNV:                   return "MeshShadingNV";
-    case CapabilityShadingRateNV:                   return "ShadingRateNV";
+//    case CapabilityShadingRateNV:                   return "ShadingRateNV";  // superseded by CapabilityFragmentDensityEXT
 #endif
+    case CapabilityFragmentDensityEXT:              return "FragmentDensityEXT";
 
     case CapabilityFragmentFullyCoveredEXT: return "FragmentFullyCoveredEXT";
 

Test/baseResults/spv.fragmentDensity-es.frag.out

+spv.fragmentDensity-es.frag
+// Module Version 10000
+// Generated by (magic number): 80007
+// Id's are bound by 18
+
+                              Capability Shader
+                              Capability FragmentDensityEXT
+                              Extension  "SPV_EXT_fragment_invocation_density"
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main" 9 11 14 16
+                              ExecutionMode 4 OriginUpperLeft
+                              Source ESSL 310
+                              SourceExtension  "GL_EXT_fragment_invocation_density"
+                              Name 4  "main"
+                              Name 9  "FragSize"
+                              Name 11  "gl_FragSizeEXT"
+                              Name 14  "FragInvocationCount"
+                              Name 16  "gl_FragInvocationCountEXT"
+                              Decorate 9(FragSize) Location 0
+                              Decorate 11(gl_FragSizeEXT) Flat
+                              Decorate 11(gl_FragSizeEXT) BuiltIn FragSizeEXT
+                              Decorate 14(FragInvocationCount) Location 2
+                              Decorate 16(gl_FragInvocationCountEXT) Flat
+                              Decorate 16(gl_FragInvocationCountEXT) BuiltIn FragInvocationCountEXT
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeInt 32 1
+               7:             TypeVector 6(int) 2
+               8:             TypePointer Output 7(ivec2)
+     9(FragSize):      8(ptr) Variable Output
+              10:             TypePointer Input 7(ivec2)
+11(gl_FragSizeEXT):     10(ptr) Variable Input
+              13:             TypePointer Output 6(int)
+14(FragInvocationCount):     13(ptr) Variable Output
+              15:             TypePointer Input 6(int)
+16(gl_FragInvocationCountEXT):     15(ptr) Variable Input
+         4(main):           2 Function None 3
+               5:             Label
+              12:    7(ivec2) Load 11(gl_FragSizeEXT)
+                              Store 9(FragSize) 12
+              17:      6(int) Load 16(gl_FragInvocationCountEXT)
+                              Store 14(FragInvocationCount) 17
+                              Return
+                              FunctionEnd

Test/baseResults/spv.fragmentDensity-neg.frag.out

+spv.fragmentDensity-neg.frag
+ERROR: 0:10: 'gl_FragSizeEXT' : required extension not requested: GL_EXT_fragment_invocation_density
+ERROR: 0:11: 'gl_FragInvocationCountEXT' : required extension not requested: GL_EXT_fragment_invocation_density
+ERROR: 2 compilation errors.  No code generated.
+
+
+SPIR-V is not generated for failed compile or link

Test/baseResults/spv.fragmentDensity.frag.out

+spv.fragmentDensity.frag
+// Module Version 10000
+// Generated by (magic number): 80007
+// Id's are bound by 21
+
+                              Capability Shader
+                              Capability FragmentDensityEXT
+                              Extension  "SPV_EXT_fragment_invocation_density"
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main" 9 13 17 19
+                              ExecutionMode 4 OriginUpperLeft
+                              Source GLSL 450
+                              SourceExtension  "GL_EXT_fragment_invocation_density"
+                              Name 4  "main"
+                              Name 9  "FragSize"
+                              Name 13  "gl_FragSizeEXT"
+                              Name 17  "FragInvocationCount"
+                              Name 19  "gl_FragInvocationCountEXT"
+                              Decorate 9(FragSize) Location 0
+                              Decorate 13(gl_FragSizeEXT) Flat
+                              Decorate 13(gl_FragSizeEXT) BuiltIn FragSizeEXT
+                              Decorate 17(FragInvocationCount) Location 2
+                              Decorate 19(gl_FragInvocationCountEXT) Flat
+                              Decorate 19(gl_FragInvocationCountEXT) BuiltIn FragInvocationCountEXT
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+               7:             TypeVector 6(float) 2
+               8:             TypePointer Output 7(fvec2)
+     9(FragSize):      8(ptr) Variable Output
+              10:             TypeInt 32 1
+              11:             TypeVector 10(int) 2
+              12:             TypePointer Input 11(ivec2)
+13(gl_FragSizeEXT):     12(ptr) Variable Input
+              16:             TypePointer Output 10(int)
+17(FragInvocationCount):     16(ptr) Variable Output
+              18:             TypePointer Input 10(int)
+19(gl_FragInvocationCountEXT):     18(ptr) Variable Input
+         4(main):           2 Function None 3
+               5:             Label
+              14:   11(ivec2) Load 13(gl_FragSizeEXT)
+              15:    7(fvec2) ConvertSToF 14
+                              Store 9(FragSize) 15
+              20:     10(int) Load 19(gl_FragInvocationCountEXT)
+                              Store 17(FragInvocationCount) 20
+                              Return
+                              FunctionEnd

Test/baseResults/spv.fragmentDensity.vert.out

+spv.fragmentDensity.vert
+ERROR: 0:10: 'gl_FragSizeEXT' : undeclared identifier 
+ERROR: 0:10: 'assign' :  cannot convert from ' temp float' to 'layout( location=0) smooth out highp 2-component vector of uint'
+ERROR: 0:11: 'gl_FragInvocationCountEXT' : undeclared identifier 
+ERROR: 0:11: 'assign' :  cannot convert from ' temp float' to 'layout( location=2) smooth out highp int'
+ERROR: 4 compilation errors.  No code generated.
+
+
+SPIR-V is not generated for failed compile or link

Test/baseResults/spv.shadingRate.frag.out

@@ -4,7 +4,7 @@ spv.shadingRate.frag
 // Id's are bound by 21
 
                               Capability Shader
-                              Capability ShadingRateNV
+                              Capability FragmentDensityEXT
                               Extension  "SPV_NV_shading_rate"
                1:             ExtInstImport  "GLSL.std.450"
                               MemoryModel Logical GLSL450
@@ -19,10 +19,10 @@ spv.shadingRate.frag
                               Name 19  "gl_InvocationsPerPixelNV"
                               Decorate 9(FragmentSize) Location 0
                               Decorate 13(gl_FragmentSizeNV) Flat
-                              Decorate 13(gl_FragmentSizeNV) BuiltIn FragmentSizeNV
+                              Decorate 13(gl_FragmentSizeNV) BuiltIn FragSizeEXT
                               Decorate 17(InvocationsPerPixel) Location 2
                               Decorate 19(gl_InvocationsPerPixelNV) Flat
-                              Decorate 19(gl_InvocationsPerPixelNV) BuiltIn InvocationsPerPixelNV
+                              Decorate 19(gl_InvocationsPerPixelNV) BuiltIn FragInvocationCountEXT
                2:             TypeVoid
                3:             TypeFunction 2
                6:             TypeFloat 32

Test/spv.fragmentDensity-es.frag

+#version 310 es
+
+#extension GL_EXT_fragment_invocation_density : require
+
+layout (location = 0) out highp ivec2 FragSize;
+layout (location = 2) out highp int FragInvocationCount;
+
+void main () {
+    FragSize = gl_FragSizeEXT;
+    FragInvocationCount = gl_FragInvocationCountEXT;
+}

Test/spv.fragmentDensity-neg.frag

+#version 450
+
+//make sure the builtins don't exist if the extension isn't enabled.
+//#extension GL_EXT_fragment_invocation_density : require
+
+layout (location = 0) out vec2 FragSize;
+layout (location = 2) out int FragInvocationCount;
+
+void main () {
+    FragSize = gl_FragSizeEXT;
+    FragInvocationCount = gl_FragInvocationCountEXT;
+}

Test/spv.fragmentDensity.frag

+#version 450
+
+#extension GL_EXT_fragment_invocation_density : require
+
+layout (location = 0) out vec2 FragSize;
+layout (location = 2) out int FragInvocationCount;
+
+void main () {
+    FragSize = gl_FragSizeEXT;
+    FragInvocationCount = gl_FragInvocationCountEXT;
+}

Test/spv.fragmentDensity.vert

+#version 450
+
+// try using a fragment-only extension in a vertex shader
+#extension GL_EXT_fragment_invocation_density : require
+
+layout (location = 0) out uvec2 FragSize;
+layout (location = 2) out int FragInvocationCount;
+
+void main () {
+    FragSize = gl_FragSizeEXT;
+    FragInvocationCount = gl_FragInvocationCountEXT;
+}

glslang/Include/BaseTypes.h

@@ -232,6 +232,9 @@ enum TBuiltInVariable {
     EbvViewIndex,
     EbvDeviceIndex,
 
+    EbvFragSizeEXT,
+    EbvFragInvocationCountEXT,
+
 #ifdef NV_EXTENSIONS
     EbvViewportMaskNV,
     EbvSecondaryPositionNV,
@@ -404,6 +407,9 @@ __inline const char* GetBuiltInVariableString(TBuiltInVariable v)
     case EbvViewIndex:                  return "ViewIndex";
     case EbvDeviceIndex:                return "DeviceIndex";
 
+    case EbvFragSizeEXT:                return "FragSizeEXT";
+    case EbvFragInvocationCountEXT:     return "FragInvocationCountEXT";
+
 #ifdef NV_EXTENSIONS
     case EbvViewportMaskNV:             return "ViewportMaskNV";
     case EbvSecondaryPositionNV:        return "SecondaryPositionNV";

glslang/MachineIndependent/Initialize.cpp

@@ -5939,6 +5939,12 @@ void TBuiltIns::initialize(int version, EProfile profile, const SpvVersion& spvV
                 "bool gl_HelperInvocation;"     // needs qualifier fixed later
                 );
 
+        if (version >= 450)
+            stageBuiltins[EShLangFragment].append( // GL_EXT_fragment_invocation_density
+                "flat in ivec2 gl_FragSizeEXT;"
+                "flat in int   gl_FragInvocationCountEXT;"
+                );
+
 #ifdef AMD_EXTENSIONS
         if (version >= 450)
             stageBuiltins[EShLangFragment].append(
@@ -5959,9 +5965,9 @@ void TBuiltIns::initialize(int version, EProfile profile, const SpvVersion& spvV
                 );
         if (version >= 450)
             stageBuiltins[EShLangFragment].append(
-                "flat in ivec2 gl_FragmentSizeNV;"
+                "flat in ivec2 gl_FragmentSizeNV;"          // GL_NV_shading_rate_image
                 "flat in int   gl_InvocationsPerPixelNV;"
-                "in vec3 gl_BaryCoordNV;"
+                "in vec3 gl_BaryCoordNV;"                   // GL_NV_fragment_shader_barycentric
                 "in vec3 gl_BaryCoordNoPerspNV;"
                 );
 
@@ -6006,13 +6012,19 @@ void TBuiltIns::initialize(int version, EProfile profile, const SpvVersion& spvV
         stageBuiltins[EShLangFragment].append(
             "highp float gl_FragDepthEXT;"       // GL_EXT_frag_depth
             );
+
+        if (version >= 310)
+            stageBuiltins[EShLangFragment].append( // GL_EXT_fragment_invocation_density
+                "flat in ivec2 gl_FragSizeEXT;"
+                "flat in int   gl_FragInvocationCountEXT;"
+            );
 #ifdef NV_EXTENSIONS
         if (version >= 320)
-            stageBuiltins[EShLangFragment].append(
+            stageBuiltins[EShLangFragment].append( // GL_NV_shading_rate_image
                 "flat in ivec2 gl_FragmentSizeNV;"
                 "flat in int   gl_InvocationsPerPixelNV;"
             );
-       if (version >= 320)
+        if (version >= 320)
             stageBuiltins[EShLangFragment].append(
                 "in vec3 gl_BaryCoordNV;"
                 "in vec3 gl_BaryCoordNoPerspNV;"
@@ -8342,6 +8354,14 @@ void TBuiltIns::identifyBuiltIns(int version, EProfile profile, const SpvVersion
         }
 #endif
 
+        if ((profile != EEsProfile && version >= 450) ||
+            (profile == EEsProfile && version >= 310)) {
+            symbolTable.setVariableExtensions("gl_FragSizeEXT",            1, &E_GL_EXT_fragment_invocation_density);
+            symbolTable.setVariableExtensions("gl_FragInvocationCountEXT", 1, &E_GL_EXT_fragment_invocation_density);
+            BuiltInVariable("gl_FragSizeEXT",            EbvFragSizeEXT, symbolTable);
+            BuiltInVariable("gl_FragInvocationCountEXT", EbvFragInvocationCountEXT, symbolTable);
+        }
+
         symbolTable.setVariableExtensions("gl_FragDepthEXT", 1, &E_GL_EXT_frag_depth);
 
         if (profile == EEsProfile && version < 320) {

glslang/MachineIndependent/Versions.cpp

@@ -205,6 +205,7 @@ void TParseVersions::initializeExtensionBehavior()
     extensionBehavior[E_GL_EXT_nonuniform_qualifier]                    = EBhDisable;
     extensionBehavior[E_GL_EXT_samplerless_texture_functions]           = EBhDisable;
     extensionBehavior[E_GL_EXT_scalar_block_layout]                     = EBhDisable;
+    extensionBehavior[E_GL_EXT_fragment_invocation_density]             = EBhDisable;
 
     extensionBehavior[E_GL_EXT_shader_16bit_storage]                    = EBhDisable;
     extensionBehavior[E_GL_EXT_shader_8bit_storage]                     = EBhDisable;
@@ -380,6 +381,7 @@ void TParseVersions::getPreamble(std::string& preamble)
             "#define GL_EXT_shader_8bit_storage 1\n"
             "#define GL_EXT_samplerless_texture_functions 1\n"
             "#define GL_EXT_scalar_block_layout 1\n"
+            "#define GL_EXT_fragment_invocation_density 1\n"
 
             // GL_KHR_shader_subgroup
             "#define GL_KHR_shader_subgroup_basic 1\n"

glslang/MachineIndependent/Versions.h

@@ -167,6 +167,7 @@ const char* const E_GL_EXT_control_flow_attributes          = "GL_EXT_control_fl
 const char* const E_GL_EXT_nonuniform_qualifier             = "GL_EXT_nonuniform_qualifier";
 const char* const E_GL_EXT_samplerless_texture_functions    = "GL_EXT_samplerless_texture_functions";
 const char* const E_GL_EXT_scalar_block_layout              = "GL_EXT_scalar_block_layout";
+const char* const E_GL_EXT_fragment_invocation_density      = "GL_EXT_fragment_invocation_density";
 
 // Arrays of extensions for the above viewportEXTs duplications
 

gtests/Spv.FromFile.cpp

@@ -271,6 +271,10 @@ INSTANTIATE_TEST_CASE_P(
         "spv.flowControl.frag",
         "spv.forLoop.frag",
         "spv.forwardFun.frag",
+        "spv.fragmentDensity.frag",
+        "spv.fragmentDensity.vert",
+        "spv.fragmentDensity-es.frag",
+        "spv.fragmentDensity-neg.frag",
         "spv.fullyCovered.frag",
         "spv.functionCall.frag",
         "spv.functionNestedOpaque.vert",

known_good.json

@@ -12,7 +12,7 @@
       "site" : "github",
       "subrepo" : "KhronosGroup/SPIRV-Headers",
       "subdir" : "External/spirv-tools/external/spirv-headers",
-      "commit" : "a2c529b5dda18838ab4b52f816acfebd774eaab3"
+      "commit" : "282879ca34563020dbe73fd8f7d45bed6755626a"
     }
   ]
 }