Implement SPV_KHR_post_depth_coverage

Added support for both extension GL_ARB_post_depth_coverage and GL_EXT_post_depth_coverage.

SPIRV/GLSL.ext.KHR.h

@@ -32,7 +32,7 @@ enum Op;
 enum Capability;
 
 static const int GLSLextKHRVersion = 100;
-static const int GLSLextKHRRevision = 1;
+static const int GLSLextKHRRevision = 2;
 
 static const char* const E_SPV_KHR_shader_ballot                = "SPV_KHR_shader_ballot";
 static const char* const E_SPV_KHR_subgroup_vote                = "SPV_KHR_subgroup_vote";
@@ -41,5 +41,6 @@ static const char* const E_SPV_KHR_multiview                    = "SPV_KHR_multi
 static const char* const E_SPV_KHR_shader_draw_parameters       = "SPV_KHR_shader_draw_parameters";
 static const char* const E_SPV_KHR_16bit_storage                = "SPV_KHR_16bit_storage";
 static const char* const E_SPV_KHR_storage_buffer_storage_class = "SPV_KHR_storage_buffer_storage_class";
+static const char* const E_SPV_KHR_post_depth_coverage          = "SPV_KHR_post_depth_coverage";
 
 #endif  // #ifndef GLSLextKHR_H

SPIRV/GlslangToSpv.cpp

@@ -980,6 +980,12 @@ TGlslangToSpvTraverser::TGlslangToSpvTraverser(const glslang::TIntermediate* gls
         if (glslangIntermediate->getEarlyFragmentTests())
             builder.addExecutionMode(shaderEntry, spv::ExecutionModeEarlyFragmentTests);
 
+        if (glslangIntermediate->getPostDepthCoverage()) {
+            builder.addCapability(spv::CapabilitySampleMaskPostDepthCoverage);
+            builder.addExecutionMode(shaderEntry, spv::ExecutionModePostDepthCoverage);
+            builder.addExtension(spv::E_SPV_KHR_post_depth_coverage);
+        }
+
         switch(glslangIntermediate->getDepth()) {
         case glslang::EldGreater:  mode = spv::ExecutionModeDepthGreater; break;
         case glslang::EldLess:     mode = spv::ExecutionModeDepthLess;    break;

SPIRV/doc.cpp

@@ -175,6 +175,7 @@ const char* ExecutionModeString(int mode)
     case 31: return "ContractionOff";
     case 32: return "Bad";
 
+    case 4446:  return "PostDepthCoverage";
     case ExecutionModeCeiling:
     default: return "Bad";
     }
@@ -843,6 +844,7 @@ const char* CapabilityString(int info)
     case 5009: return "ImageGatherBiasLodAMD";
 #endif
 
+    case 4447: return "SampleMaskPostDepthCoverage";
 #ifdef NV_EXTENSIONS
     case 5251: return "GeometryShaderPassthroughNV";
     case 5254: return "ShaderViewportIndexLayerNV";

SPIRV/spirv.hpp

@@ -47,11 +47,11 @@ namespace spv {
 typedef unsigned int Id;
 
 #define SPV_VERSION 0x10000
-#define SPV_REVISION 10
+#define SPV_REVISION 11
 
 static const unsigned int MagicNumber = 0x07230203;
 static const unsigned int Version = 0x00010000;
-static const unsigned int Revision = 10;
+static const unsigned int Revision = 11;
 static const unsigned int OpCodeMask = 0xffff;
 static const unsigned int WordCountShift = 16;
 
@@ -122,6 +122,7 @@ enum ExecutionMode {
     ExecutionModeOutputTriangleStrip = 29,
     ExecutionModeVecTypeHint = 30,
     ExecutionModeContractionOff = 31,
+    ExecutionModePostDepthCoverage = 4446,
     ExecutionModeMax = 0x7fffffff,
 };
 
@@ -628,6 +629,7 @@ enum Capability {
     CapabilityMultiView = 4439,
     CapabilityVariablePointersStorageBuffer = 4441,
     CapabilityVariablePointers = 4442,
+    CapabilitySampleMaskPostDepthCoverage = 4447,
     CapabilitySampleMaskOverrideCoverageNV = 5249,
     CapabilityGeometryShaderPassthroughNV = 5251,
     CapabilityShaderViewportIndexLayerNV = 5254,

Test/baseResults/spv.arbPostDepthCoverage.frag.out

@@ -0,0 +1,43 @@
+spv.arbPostDepthCoverage.frag
+// Module Version 10000
+// Generated by (magic number): 80001
+// Id's are bound by 18
+
+                              Capability Shader
+                              Capability SampleRateShading
+                              Capability SampleMaskPostDepthCoverage
+                              Extension  "SPV_KHR_post_depth_coverage"
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main" 8 13
+                              ExecutionMode 4 OriginUpperLeft
+                              ExecutionMode 4 EarlyFragmentTests
+                              ExecutionMode 4 PostDepthCoverage
+                              Source GLSL 450
+                              SourceExtension  "GL_ARB_post_depth_coverage"
+                              SourceExtension  "GL_EXT_post_depth_coverage"
+                              Name 4  "main"
+                              Name 8  "readSampleMaskIn"
+                              Name 13  "gl_SampleMaskIn"
+                              Decorate 8(readSampleMaskIn) Location 0
+                              Decorate 13(gl_SampleMaskIn) Flat
+                              Decorate 13(gl_SampleMaskIn) BuiltIn SampleMask
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeInt 32 1
+               7:             TypePointer Output 6(int)
+8(readSampleMaskIn):      7(ptr) Variable Output
+               9:             TypeInt 32 0
+              10:      9(int) Constant 1
+              11:             TypeArray 6(int) 10
+              12:             TypePointer Input 11
+13(gl_SampleMaskIn):     12(ptr) Variable Input
+              14:      6(int) Constant 0
+              15:             TypePointer Input 6(int)
+         4(main):           2 Function None 3
+               5:             Label
+              16:     15(ptr) AccessChain 13(gl_SampleMaskIn) 14
+              17:      6(int) Load 16
+                              Store 8(readSampleMaskIn) 17
+                              Return
+                              FunctionEnd

Test/baseResults/spv.arbPostDepthCoverage_Error.frag.out

@@ -0,0 +1,7 @@
+spv.arbPostDepthCoverage_Error.frag
+ERROR: 0:7: 'early_fragment_tests' : can only apply to a standalone qualifier 
+ERROR: 0:7: 'post_depth_coverage' : can only apply to a standalone qualifier 
+ERROR: 2 compilation errors.  No code generated.
+
+
+SPIR-V is not generated for failed compile or link

Test/baseResults/spv.extPostDepthCoverage.frag.out

@@ -0,0 +1,23 @@
+spv.extPostDepthCoverage.frag
+// Module Version 10000
+// Generated by (magic number): 80001
+// Id's are bound by 6
+
+                              Capability Shader
+                              Capability SampleMaskPostDepthCoverage
+                              Extension  "SPV_KHR_post_depth_coverage"
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main"
+                              ExecutionMode 4 OriginUpperLeft
+                              ExecutionMode 4 EarlyFragmentTests
+                              ExecutionMode 4 PostDepthCoverage
+                              Source ESSL 310
+                              SourceExtension  "GL_EXT_post_depth_coverage"
+                              Name 4  "main"
+               2:             TypeVoid
+               3:             TypeFunction 2
+         4(main):           2 Function None 3
+               5:             Label
+                              Return
+                              FunctionEnd

Test/baseResults/spv.extPostDepthCoverage_Error.frag.out

@@ -0,0 +1,4 @@
+spv.extPostDepthCoverage_Error.frag
+ERROR: Linking fragment stage: post_depth_coverage requires early_fragment_tests
+
+SPIR-V is not generated for failed compile or link

Test/spv.arbPostDepthCoverage.frag

@@ -0,0 +1,13 @@
+#version 450
+
+#extension GL_ARB_post_depth_coverage : enable
+#extension GL_EXT_post_depth_coverage : enable //according to ARB_post_depth_coverage, 
+                                               //if both enabled, this one should be ignored
+precision highp int;
+layout(post_depth_coverage) in;
+
+layout (location = 0) out int readSampleMaskIn;
+
+void main () {
+    readSampleMaskIn = gl_SampleMaskIn[0];
+}

Test/spv.arbPostDepthCoverage_Error.frag

@@ -0,0 +1,12 @@
+#version 310 es
+
+#extension GL_ARB_post_depth_coverage : enable
+
+precision highp float;
+
+layout(post_depth_coverage, location = 0) in float a;  // should fail since post_depth_coverage may only
+                                                       // be declared on in only (not with variable declarations)
+
+void main () {
+
+}

Test/spv.extPostDepthCoverage.frag

@@ -0,0 +1,9 @@
+#version 310 es
+
+#extension GL_EXT_post_depth_coverage : enable
+
+layout(post_depth_coverage) in;
+layout(early_fragment_tests) in;
+
+void main () {
+}

Test/spv.extPostDepthCoverage_Error.frag

@@ -0,0 +1,9 @@
+#version 450
+
+#extension GL_EXT_post_depth_coverage : enable
+
+layout(post_depth_coverage) in; // should fail since for GL_EXT_post_depth_coverage
+                                // explicit declaration of early_fragment_tests is required
+
+void main () {
+}

glslang/Include/Types.h

@@ -968,6 +968,7 @@ struct TShaderQualifiers {
     int localSize[3];         // compute shader
     int localSizeSpecId[3];   // compute shader specialization id for gl_WorkGroupSize
     bool earlyFragmentTests;  // fragment input
+    bool postDepthCoverage;   // fragment input
     TLayoutDepth layoutDepth;
     bool blendEquation;       // true if any blend equation was specified
 
@@ -992,6 +993,7 @@ struct TShaderQualifiers {
         localSizeSpecId[1] = TQualifier::layoutNotSet;
         localSizeSpecId[2] = TQualifier::layoutNotSet;
         earlyFragmentTests = false;
+        postDepthCoverage = false;
         layoutDepth = EldNone;
         blendEquation = false;
 #ifdef NV_EXTENSIONS
@@ -1029,6 +1031,8 @@ struct TShaderQualifiers {
         }
         if (src.earlyFragmentTests)
             earlyFragmentTests = true;
+        if (src.postDepthCoverage)
+            postDepthCoverage = true;
         if (src.layoutDepth)
             layoutDepth = src.layoutDepth;
         if (src.blendEquation)

glslang/MachineIndependent/ParseHelper.cpp

@@ -4015,6 +4015,14 @@ void TParseContext::setLayoutQualifier(const TSourceLoc& loc, TPublicType& publi
             publicType.shaderQualifiers.earlyFragmentTests = true;
             return;
         }
+        if (id == "post_depth_coverage") {
+            requireExtensions(loc, Num_post_depth_coverageEXTs, post_depth_coverageEXTs, "post depth coverage");
+            if (extensionTurnedOn(E_GL_ARB_post_depth_coverage)) {
+                publicType.shaderQualifiers.earlyFragmentTests = true;
+            }
+            publicType.shaderQualifiers.postDepthCoverage = true;
+            return;
+        }
         for (TLayoutDepth depth = (TLayoutDepth)(EldNone + 1); depth < EldCount; depth = (TLayoutDepth)(depth+1)) {
             if (id == TQualifier::getLayoutDepthString(depth)) {
                 requireProfile(loc, ECoreProfile | ECompatibilityProfile, "depth layout qualifier");
@@ -4788,6 +4796,8 @@ void TParseContext::checkNoShaderLayouts(const TSourceLoc& loc, const TShaderQua
         error(loc, message, "invocations", "");
     if (shaderQualifiers.earlyFragmentTests)
         error(loc, message, "early_fragment_tests", "");
+    if (shaderQualifiers.postDepthCoverage)
+        error(loc, message, "post_depth_coverage", "");
     for (int i = 0; i < 3; ++i) {
         if (shaderQualifiers.localSize[i] > 1)
             error(loc, message, "local_size", "");
@@ -6282,6 +6292,12 @@ void TParseContext::updateStandaloneQualifierDefaults(const TSourceLoc& loc, con
         else
             error(loc, "can only apply to 'in'", "early_fragment_tests", "");
     }
+    if (publicType.shaderQualifiers.postDepthCoverage) {
+        if (publicType.qualifier.storage == EvqVaryingIn)
+            intermediate.setPostDepthCoverage();
+        else
+            error(loc, "can only apply to 'in'", "post_coverage_coverage", "");
+    }
     if (publicType.shaderQualifiers.blendEquation) {
         if (publicType.qualifier.storage != EvqVaryingOut)
             error(loc, "can only apply to 'out'", "blend equation", "");

glslang/MachineIndependent/Versions.cpp

@@ -181,9 +181,11 @@ void TParseVersions::initializeExtensionBehavior()
     extensionBehavior[E_GL_ARB_sparse_texture_clamp]         = EBhDisable;
     extensionBehavior[E_GL_ARB_shader_stencil_export]        = EBhDisable;
 //    extensionBehavior[E_GL_ARB_cull_distance]                = EBhDisable;    // present for 4.5, but need extension control over block members
+    extensionBehavior[E_GL_ARB_post_depth_coverage]          = EBhDisable;
 
     extensionBehavior[E_GL_EXT_shader_non_constant_global_initializers] = EBhDisable;
-    extensionBehavior[E_GL_EXT_shader_image_load_formatted]  = EBhDisable;
+    extensionBehavior[E_GL_EXT_shader_image_load_formatted]             = EBhDisable;
+    extensionBehavior[E_GL_EXT_post_depth_coverage]                     = EBhDisable;
 
     // #line and #include
     extensionBehavior[E_GL_GOOGLE_cpp_style_line_directive]          = EBhDisable;
@@ -316,8 +318,10 @@ void TParseVersions::getPreamble(std::string& preamble)
             "#define GL_ARB_sparse_texture_clamp 1\n"
             "#define GL_ARB_shader_stencil_export 1\n"
 //            "#define GL_ARB_cull_distance 1\n"    // present for 4.5, but need extension control over block members
+            "#define GL_ARB_post_depth_coverage 1\n"
             "#define GL_EXT_shader_non_constant_global_initializers 1\n"
             "#define GL_EXT_shader_image_load_formatted 1\n"
+            "#define GL_EXT_post_depth_coverage 1\n"
 
 #ifdef AMD_EXTENSIONS
             "#define GL_AMD_shader_ballot 1\n"

glslang/MachineIndependent/Versions.h

@@ -135,6 +135,7 @@ const char* const E_GL_ARB_sparse_texture2              = "GL_ARB_sparse_texture
 const char* const E_GL_ARB_sparse_texture_clamp         = "GL_ARB_sparse_texture_clamp";
 const char* const E_GL_ARB_shader_stencil_export        = "GL_ARB_shader_stencil_export";
 // const char* const E_GL_ARB_cull_distance            = "GL_ARB_cull_distance";  // present for 4.5, but need extension control over block members
+const char* const E_GL_ARB_post_depth_coverage          = "GL_ARB_post_depth_coverage";
 
 const char* const E_GL_EXT_shader_non_constant_global_initializers = "GL_EXT_shader_non_constant_global_initializers";
 const char* const E_GL_EXT_shader_image_load_formatted = "GL_EXT_shader_image_load_formatted";
@@ -142,6 +143,12 @@ const char* const E_GL_EXT_shader_image_load_formatted = "GL_EXT_shader_image_lo
 // EXT extensions
 const char* const E_GL_EXT_device_group                 = "GL_EXT_device_group";
 const char* const E_GL_EXT_multiview                    = "GL_EXT_multiview";
+const char* const E_GL_EXT_post_depth_coverage          = "GL_EXT_post_depth_coverage";
+
+// Arrays of extensions for the above viewportEXTs duplications
+
+const char* const post_depth_coverageEXTs[] = { E_GL_ARB_post_depth_coverage, E_GL_EXT_post_depth_coverage };
+const int Num_post_depth_coverageEXTs = sizeof(post_depth_coverageEXTs) / sizeof(post_depth_coverageEXTs[0]);
 
 // OVR extensions
 const char* const E_GL_OVR_multiview                    = "GL_OVR_multiview";

glslang/MachineIndependent/intermOut.cpp

@@ -1085,6 +1085,8 @@ void TIntermediate::output(TInfoSink& infoSink, bool tree)
             infoSink.debug << "gl_FragCoord origin is upper left\n";
         if (earlyFragmentTests)
             infoSink.debug << "using early_fragment_tests\n";
+        if (postDepthCoverage)
+            infoSink.debug << "using post_depth_coverage\n";
         if (depthLayout != EldNone)
             infoSink.debug << "using " << TQualifier::getLayoutDepthString(depthLayout) << "\n";
         if (blendEquations != 0) {

glslang/MachineIndependent/linkValidate.cpp

@@ -101,6 +101,9 @@ void TIntermediate::merge(TInfoSink& infoSink, TIntermediate& unit)
     if (! earlyFragmentTests)
         earlyFragmentTests = unit.earlyFragmentTests;
 
+    if (!postDepthCoverage)
+        postDepthCoverage = unit.postDepthCoverage;
+
     if (depthLayout == EldNone)
         depthLayout = unit.depthLayout;
     else if (depthLayout != unit.depthLayout)
@@ -485,6 +488,11 @@ void TIntermediate::finalCheck(TInfoSink& infoSink, bool keepUncalled)
             error(infoSink, "At least one shader must specify a layout(max_vertices = value)");
         break;
     case EShLangFragment:
+        // for GL_ARB_post_depth_coverage, EarlyFragmentTest is set automatically in 
+        // ParseHelper.cpp. So if we reach here, this must be GL_EXT_post_depth_coverage 
+        // requiring explicit early_fragment_tests
+        if (getPostDepthCoverage() && !getEarlyFragmentTests())
+            error(infoSink, "post_depth_coverage requires early_fragment_tests");
         break;
     case EShLangCompute:
         break;

glslang/MachineIndependent/localintermediate.h

@@ -164,8 +164,8 @@ public:
         numEntryPoints(0), numErrors(0), numPushConstants(0), recursive(false),
         invocations(TQualifier::layoutNotSet), vertices(TQualifier::layoutNotSet), inputPrimitive(ElgNone), outputPrimitive(ElgNone),
         pixelCenterInteger(false), originUpperLeft(false),
-        vertexSpacing(EvsNone), vertexOrder(EvoNone), pointMode(false), earlyFragmentTests(false), depthLayout(EldNone), depthReplacing(false), blendEquations(0),
+        vertexSpacing(EvsNone), vertexOrder(EvoNone), pointMode(false), earlyFragmentTests(false), postDepthCoverage(false), depthLayout(EldNone), depthReplacing(false),
-        xfbMode(false), multiStream(false),
+        blendEquations(0), xfbMode(false), multiStream(false),
 #ifdef NV_EXTENSIONS
         layoutOverrideCoverage(false),
         geoPassthroughEXT(false),
@@ -403,6 +403,8 @@ public:
     bool getPixelCenterInteger() const { return pixelCenterInteger; }
     void setEarlyFragmentTests() { earlyFragmentTests = true; }
     bool getEarlyFragmentTests() const { return earlyFragmentTests; }
+    void setPostDepthCoverage() { postDepthCoverage = true; }
+    bool getPostDepthCoverage() const { return postDepthCoverage; }
     bool setDepth(TLayoutDepth d)
     {
         if (depthLayout != EldNone)
@@ -513,6 +515,7 @@ protected:
     int localSize[3];
     int localSizeSpecId[3];
     bool earlyFragmentTests;
+    bool postDepthCoverage;
     TLayoutDepth depthLayout;
     bool depthReplacing;
     int blendEquations;        // an 'or'ing of masks of shifts of TBlendEquationShift

gtests/Spv.FromFile.cpp

@@ -226,6 +226,8 @@ INSTANTIATE_TEST_CASE_P(
         "spv.aggOps.frag",
         "spv.always-discard.frag",
         "spv.always-discard2.frag",
+        "spv.arbPostDepthCoverage.frag",
+        "spv.arbPostDepthCoverage_Error.frag",
         "spv.bitCast.frag",
         "spv.bool.vert",
         "spv.boolInBlock.frag",
@@ -242,6 +244,8 @@ INSTANTIATE_TEST_CASE_P(
         "spv.drawParams.vert",
         "spv.doWhileLoop.frag",
         "spv.earlyReturnDiscard.frag",
+        "spv.extPostDepthCoverage.frag",
+        "spv.extPostDepthCoverage_Error.frag",
         "spv.flowControl.frag",
         "spv.forLoop.frag",
         "spv.forwardFun.frag",