Merge pull request #3043 from gnl21/helper-invocation

Change Volatile generation for HelperInvocation

SPIRV/GlslangToSpv.cpp

@@ -4741,6 +4741,16 @@ spv::Id TGlslangToSpvTraverser::accessChainLoad(const glslang::TType& type)
     spv::Builder::AccessChain::CoherentFlags coherentFlags = builder.getAccessChain().coherentFlags;
     coherentFlags |= TranslateCoherent(type);
 
+    spv::MemoryAccessMask accessMask = spv::MemoryAccessMask(TranslateMemoryAccess(coherentFlags) & ~spv::MemoryAccessMakePointerAvailableKHRMask);
+    // If the value being loaded is HelperInvocation, SPIR-V 1.6 is being generated (so that
+    // SPV_EXT_demote_to_helper_invocation is in core) and the memory model is in use, add
+    // the Volatile MemoryAccess semantic.
+    if (type.getQualifier().builtIn == glslang::EbvHelperInvocation &&
+        glslangIntermediate->usingVulkanMemoryModel() &&
+        glslangIntermediate->getSpv().spv >= glslang::EShTargetSpv_1_6) {
+        accessMask = spv::MemoryAccessMask(accessMask | spv::MemoryAccessVolatileMask);
+    }
+
     unsigned int alignment = builder.getAccessChain().alignment;
     alignment |= type.getBufferReferenceAlignment();
 
@@ -4748,7 +4758,7 @@ spv::Id TGlslangToSpvTraverser::accessChainLoad(const glslang::TType& type)
         TranslateNonUniformDecoration(builder.getAccessChain().coherentFlags),
         TranslateNonUniformDecoration(type.getQualifier()),
         nominalTypeId,
-        spv::MemoryAccessMask(TranslateMemoryAccess(coherentFlags) & ~spv::MemoryAccessMakePointerAvailableKHRMask),
+        accessMask,
         TranslateMemoryScope(coherentFlags),
         alignment);
 
@@ -8968,6 +8978,7 @@ spv::Id TGlslangToSpvTraverser::getSymbolId(const glslang::TIntermSymbol* symbol
 
     // Add volatile decoration to HelperInvocation for spirv1.6 and beyond
     if (builtIn == spv::BuiltInHelperInvocation &&
+        !glslangIntermediate->usingVulkanMemoryModel() &&
         glslangIntermediate->getSpv().spv >= glslang::EShTargetSpv_1_6) {
         builder.addDecoration(id, spv::DecorationVolatile);
     }

Test/baseResults/spv.1.6.helperInvocation.memmodel.frag.out

@@ -0,0 +1,48 @@
+spv.1.6.helperInvocation.memmodel.frag
+// Module Version 10600
+// Generated by (magic number): 8000b
+// Id's are bound by 21
+
+                              Capability Shader
+                              Capability VulkanMemoryModelKHR
+                              Capability DemoteToHelperInvocationEXT
+                              Extension  "SPV_EXT_demote_to_helper_invocation"
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical VulkanKHR
+                              EntryPoint Fragment 4  "main" 9 14
+                              ExecutionMode 4 OriginUpperLeft
+                              Source ESSL 310
+                              SourceExtension  "GL_EXT_demote_to_helper_invocation"
+                              Name 4  "main"
+                              Name 7  "B"
+                              MemberName 7(B) 0  "o"
+                              Name 9  ""
+                              Name 14  "gl_HelperInvocation"
+                              MemberDecorate 7(B) 0 Offset 0
+                              Decorate 7(B) Block
+                              Decorate 9 DescriptorSet 0
+                              Decorate 9 Binding 0
+                              Decorate 14(gl_HelperInvocation) BuiltIn HelperInvocation
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+            7(B):             TypeStruct 6(float)
+               8:             TypePointer StorageBuffer 7(B)
+               9:      8(ptr) Variable StorageBuffer
+              10:             TypeInt 32 1
+              11:     10(int) Constant 0
+              12:             TypeBool
+              13:             TypePointer Input 12(bool)
+14(gl_HelperInvocation):     13(ptr) Variable Input
+              16:    6(float) Constant 1065353216
+              17:    6(float) Constant 0
+              19:             TypePointer StorageBuffer 6(float)
+         4(main):           2 Function None 3
+               5:             Label
+                              DemoteToHelperInvocationEXT
+              15:    12(bool) Load 14(gl_HelperInvocation) Volatile 
+              18:    6(float) Select 15 16 17
+              20:     19(ptr) AccessChain 9 11
+                              Store 20 18
+                              Return
+                              FunctionEnd

Test/spv.1.6.helperInvocation.memmodel.frag

@@ -0,0 +1,16 @@
+#version 310 es
+
+#pragma use_vulkan_memory_model
+
+#extension GL_EXT_demote_to_helper_invocation : require
+
+precision highp float;
+
+layout (set=0, binding=0) buffer B {
+   float o;
+};
+
+void main() {
+   demote;
+   o = gl_HelperInvocation ? 1.0 : 0.0;
+}

gtests/Spv.FromFile.cpp

@@ -660,6 +660,7 @@ INSTANTIATE_TEST_SUITE_P(
     ::testing::ValuesIn(std::vector<std::string>({
         "spv.1.6.conditionalDiscard.frag",
         "spv.1.6.helperInvocation.frag",
+        "spv.1.6.helperInvocation.memmodel.frag",
         "spv.1.6.specConstant.comp",
         "spv.1.6.samplerBuffer.frag",
         "spv.1.6.separate.frag",