Avoid duplicate BuiltIn variables for ray tracing matrices (fix #2921)

Fixes an issue where invalid SPIR-V was generated when
gl_ObjectToWorldEXT and gl_ObjectToWorld3x4EXT, or
gl_WorldToObjectEXT and gl_WorldToObject3x4EXT, were used in the same
shader. The SPIR-V specification requires that there be at most one
OpVariable decorated with a given BuiltIn value.

SPIRV/GlslangToSpv.cpp

@@ -260,6 +260,7 @@ protected:
     std::unordered_map<std::string, spv::Id> extBuiltinMap;
 
     std::unordered_map<long long, spv::Id> symbolValues;
+    std::unordered_map<uint32_t, spv::Id> builtInVariableIds;
     std::unordered_set<long long> rValueParameters;  // set of formal function parameters passed as rValues,
                                                // rather than a pointer
     std::unordered_map<std::string, spv::Function*> functionMap;
@@ -8750,7 +8751,32 @@ spv::Id TGlslangToSpvTraverser::getSymbolId(const glslang::TIntermSymbol* symbol
     // it was not found, create it
     spv::BuiltIn builtIn = TranslateBuiltInDecoration(symbol->getQualifier().builtIn, false);
     auto forcedType = getForcedType(symbol->getQualifier().builtIn, symbol->getType());
+
+    // There are pairs of symbols that map to the same SPIR-V built-in:
+    // gl_ObjectToWorldEXT and gl_ObjectToWorld3x4EXT, and gl_WorldToObjectEXT
+    // and gl_WorldToObject3x4EXT. SPIR-V forbids having two OpVariables
+    // with the same BuiltIn in the same storage class, so we must re-use one.
+    const bool mayNeedToReuseBuiltIn =
+        builtIn == spv::BuiltInObjectToWorldKHR ||
+        builtIn == spv::BuiltInWorldToObjectKHR;
+
+    if (mayNeedToReuseBuiltIn) {
+        auto iter = builtInVariableIds.find(uint32_t(builtIn));
+        if (builtInVariableIds.end() != iter) {
+            id = iter->second;
+            symbolValues[symbol->getId()] = id;
+            if (forcedType.second != spv::NoType)
+                forceType[id] = forcedType.second;
+            return id;
+        }
+    }
+
     id = createSpvVariable(symbol, forcedType.first);
+
+    if (mayNeedToReuseBuiltIn) {
+        builtInVariableIds.insert({uint32_t(builtIn), id});
+    }
+
     symbolValues[symbol->getId()] = id;
     if (forcedType.second != spv::NoType)
         forceType[id] = forcedType.second;

Test/baseResults/spv.ext.AnyHitShader.rahit.out

@@ -1,7 +1,7 @@
 spv.ext.AnyHitShader.rahit
 // Module Version 10400
 // Generated by (magic number): 8000a
-// Id's are bound by 110
+// Id's are bound by 108
 
                               Capability GroupNonUniform
                               Capability RayTracingKHR
@@ -10,7 +10,7 @@ spv.ext.AnyHitShader.rahit
                               Extension  "SPV_KHR_ray_tracing"
                1:             ExtInstImport  "GLSL.std.450"
                               MemoryModel Logical GLSL450
-                              EntryPoint AnyHitKHR 4  "main" 11 14 20 23 26 33 36 39 42 47 50 53 58 64 67 70 76 80 84 87 101
+                              EntryPoint AnyHitKHR 4  "main" 11 14 20 23 26 33 36 39 42 47 50 53 58 64 67 70 82 85 99
                               Source GLSL 460
                               SourceExtension  "GL_EXT_ray_cull_mask"
                               SourceExtension  "GL_EXT_ray_tracing"
@@ -49,13 +49,11 @@ spv.ext.AnyHitShader.rahit
                               Name 69  "v15"
                               Name 70  "gl_GeometryIndexEXT"
                               Name 75  "v16"
-                              Name 76  "gl_ObjectToWorld3x4EXT"
-                              Name 79  "v17"
-                              Name 80  "gl_WorldToObject3x4EXT"
-                              Name 83  "v18"
-                              Name 84  "gl_CullMaskEXT"
-                              Name 87  "incomingPayload"
-                              Name 101  "gl_SubgroupSize"
+                              Name 78  "v17"
+                              Name 81  "v18"
+                              Name 82  "gl_CullMaskEXT"
+                              Name 85  "incomingPayload"
+                              Name 99  "gl_SubgroupSize"
                               Decorate 11(gl_LaunchIDEXT) BuiltIn LaunchIdKHR
                               Decorate 14(gl_LaunchSizeEXT) BuiltIn LaunchSizeKHR
                               Decorate 20(gl_PrimitiveID) BuiltIn PrimitiveId
@@ -72,13 +70,11 @@ spv.ext.AnyHitShader.rahit
                               Decorate 64(gl_ObjectToWorldEXT) BuiltIn ObjectToWorldKHR
                               Decorate 67(gl_WorldToObjectEXT) BuiltIn WorldToObjectKHR
                               Decorate 70(gl_GeometryIndexEXT) BuiltIn RayGeometryIndexKHR
-                              Decorate 76(gl_ObjectToWorld3x4EXT) BuiltIn ObjectToWorldKHR
-                              Decorate 80(gl_WorldToObject3x4EXT) BuiltIn WorldToObjectKHR
-                              Decorate 84(gl_CullMaskEXT) BuiltIn CullMaskKHR
-                              Decorate 101(gl_SubgroupSize) RelaxedPrecision
-                              Decorate 101(gl_SubgroupSize) BuiltIn SubgroupSize
-                              Decorate 102 RelaxedPrecision
-                              Decorate 103 RelaxedPrecision
+                              Decorate 82(gl_CullMaskEXT) BuiltIn CullMaskKHR
+                              Decorate 99(gl_SubgroupSize) RelaxedPrecision
+                              Decorate 99(gl_SubgroupSize) BuiltIn SubgroupSize
+                              Decorate 100 RelaxedPrecision
+                              Decorate 101 RelaxedPrecision
                2:             TypeVoid
                3:             TypeFunction 2
                6:             TypeInt 32 0
@@ -118,18 +114,16 @@ spv.ext.AnyHitShader.rahit
               72:             TypeVector 28(float) 4
               73:             TypeMatrix 72(fvec4) 3
               74:             TypePointer Function 73
-76(gl_ObjectToWorld3x4EXT):     63(ptr) Variable Input
-80(gl_WorldToObject3x4EXT):     63(ptr) Variable Input
-84(gl_CullMaskEXT):     57(ptr) Variable Input
-              86:             TypePointer IncomingRayPayloadKHR 72(fvec4)
-87(incomingPayload):     86(ptr) Variable IncomingRayPayloadKHR
-              88:   28(float) Constant 1056964608
-              89:   72(fvec4) ConstantComposite 88 88 88 88
-              91:     16(int) Constant 1
-              92:             TypeBool
-              97:      6(int) Constant 0
-101(gl_SubgroupSize):     57(ptr) Variable Input
-             104:             TypePointer IncomingRayPayloadKHR 28(float)
+82(gl_CullMaskEXT):     57(ptr) Variable Input
+              84:             TypePointer IncomingRayPayloadKHR 72(fvec4)
+85(incomingPayload):     84(ptr) Variable IncomingRayPayloadKHR
+              86:   28(float) Constant 1056964608
+              87:   72(fvec4) ConstantComposite 86 86 86 86
+              89:     16(int) Constant 1
+              90:             TypeBool
+              95:      6(int) Constant 0
+99(gl_SubgroupSize):     57(ptr) Variable Input
+             102:             TypePointer IncomingRayPayloadKHR 28(float)
          4(main):           2 Function None 3
                5:             Label
            9(v0):      8(ptr) Variable Function
@@ -149,8 +143,8 @@ spv.ext.AnyHitShader.rahit
          66(v14):     61(ptr) Variable Function
          69(v15):     17(ptr) Variable Function
          75(v16):     74(ptr) Variable Function
-         79(v17):     74(ptr) Variable Function
-         83(v18):     55(ptr) Variable Function
+         78(v17):     74(ptr) Variable Function
+         81(v18):     55(ptr) Variable Function
               12:    7(ivec3) Load 11(gl_LaunchIDEXT)
                               Store 9(v0) 12
               15:    7(ivec3) Load 14(gl_LaunchSizeEXT)
@@ -183,28 +177,28 @@ spv.ext.AnyHitShader.rahit
                               Store 66(v14) 68
               71:     16(int) Load 70(gl_GeometryIndexEXT)
                               Store 69(v15) 71
-              77:          60 Load 76(gl_ObjectToWorld3x4EXT)
-              78:          73 Transpose 77
-                              Store 75(v16) 78
-              81:          60 Load 80(gl_WorldToObject3x4EXT)
-              82:          73 Transpose 81
-                              Store 79(v17) 82
-              85:      6(int) Load 84(gl_CullMaskEXT)
-                              Store 83(v18) 85
-                              Store 87(incomingPayload) 89
-              90:     16(int) Load 18(v2)
-              93:    92(bool) IEqual 90 91
-                              SelectionMerge 95 None
-                              BranchConditional 93 94 95
-              94:               Label
+              76:          60 Load 64(gl_ObjectToWorldEXT)
+              77:          73 Transpose 76
+                              Store 75(v16) 77
+              79:          60 Load 67(gl_WorldToObjectEXT)
+              80:          73 Transpose 79
+                              Store 78(v17) 80
+              83:      6(int) Load 82(gl_CullMaskEXT)
+                              Store 81(v18) 83
+                              Store 85(incomingPayload) 87
+              88:     16(int) Load 18(v2)
+              91:    90(bool) IEqual 88 89
+                              SelectionMerge 93 None
+                              BranchConditional 91 92 93
+              92:               Label
                                 IgnoreIntersectionKHR
-              95:             Label
-             102:      6(int) Load 101(gl_SubgroupSize)
-             103:   28(float) ConvertUToF 102
-             105:    104(ptr) AccessChain 87(incomingPayload) 97
-             106:   28(float) Load 105
-             107:   28(float) FAdd 106 103
-             108:    104(ptr) AccessChain 87(incomingPayload) 97
-                              Store 108 107
+              93:             Label
+             100:      6(int) Load 99(gl_SubgroupSize)
+             101:   28(float) ConvertUToF 100
+             103:    102(ptr) AccessChain 85(incomingPayload) 95
+             104:   28(float) Load 103
+             105:   28(float) FAdd 104 101
+             106:    102(ptr) AccessChain 85(incomingPayload) 95
+                              Store 106 105
                               TerminateRayKHR
                               FunctionEnd

Test/baseResults/spv.ext.ClosestHitShader.rchit.out

@@ -1,7 +1,7 @@
 spv.ext.ClosestHitShader.rchit
 // Module Version 10400
 // Generated by (magic number): 8000a
-// Id's are bound by 104
+// Id's are bound by 102
 
                               Capability RayTracingKHR
                               Capability RayCullMaskKHR
@@ -9,7 +9,7 @@ spv.ext.ClosestHitShader.rchit
                               Extension  "SPV_KHR_ray_tracing"
                1:             ExtInstImport  "GLSL.std.450"
                               MemoryModel Logical GLSL450
-                              EntryPoint ClosestHitKHR 4  "main" 11 14 20 23 26 33 36 39 42 47 50 53 58 64 67 70 76 80 84 88 101 103
+                              EntryPoint ClosestHitKHR 4  "main" 11 14 20 23 26 33 36 39 42 47 50 53 58 64 67 70 82 86 99 101
                               Source GLSL 460
                               SourceExtension  "GL_EXT_ray_cull_mask"
                               SourceExtension  "GL_EXT_ray_tracing"
@@ -47,14 +47,12 @@ spv.ext.ClosestHitShader.rchit
                               Name 69  "v15"
                               Name 70  "gl_GeometryIndexEXT"
                               Name 75  "v16"
-                              Name 76  "gl_ObjectToWorld3x4EXT"
-                              Name 79  "v17"
-                              Name 80  "gl_WorldToObject3x4EXT"
-                              Name 83  "v18"
-                              Name 84  "gl_CullMaskEXT"
-                              Name 88  "accEXT"
-                              Name 101  "incomingPayload"
-                              Name 103  "localPayload"
+                              Name 78  "v17"
+                              Name 81  "v18"
+                              Name 82  "gl_CullMaskEXT"
+                              Name 86  "accEXT"
+                              Name 99  "incomingPayload"
+                              Name 101  "localPayload"
                               Decorate 11(gl_LaunchIDEXT) BuiltIn LaunchIdKHR
                               Decorate 14(gl_LaunchSizeEXT) BuiltIn LaunchSizeKHR
                               Decorate 20(gl_PrimitiveID) BuiltIn PrimitiveId
@@ -71,11 +69,9 @@ spv.ext.ClosestHitShader.rchit
                               Decorate 64(gl_ObjectToWorldEXT) BuiltIn ObjectToWorldKHR
                               Decorate 67(gl_WorldToObjectEXT) BuiltIn WorldToObjectKHR
                               Decorate 70(gl_GeometryIndexEXT) BuiltIn RayGeometryIndexKHR
-                              Decorate 76(gl_ObjectToWorld3x4EXT) BuiltIn ObjectToWorldKHR
-                              Decorate 80(gl_WorldToObject3x4EXT) BuiltIn WorldToObjectKHR
-                              Decorate 84(gl_CullMaskEXT) BuiltIn CullMaskKHR
-                              Decorate 88(accEXT) DescriptorSet 0
-                              Decorate 88(accEXT) Binding 0
+                              Decorate 82(gl_CullMaskEXT) BuiltIn CullMaskKHR
+                              Decorate 86(accEXT) DescriptorSet 0
+                              Decorate 86(accEXT) Binding 0
                2:             TypeVoid
                3:             TypeFunction 2
                6:             TypeInt 32 0
@@ -115,26 +111,24 @@ spv.ext.ClosestHitShader.rchit
               72:             TypeVector 28(float) 4
               73:             TypeMatrix 72(fvec4) 3
               74:             TypePointer Function 73
-76(gl_ObjectToWorld3x4EXT):     63(ptr) Variable Input
-80(gl_WorldToObject3x4EXT):     63(ptr) Variable Input
-84(gl_CullMaskEXT):     57(ptr) Variable Input
-              86:             TypeAccelerationStructureKHR
-              87:             TypePointer UniformConstant 86
-      88(accEXT):     87(ptr) Variable UniformConstant
-              90:      6(int) Constant 0
-              91:      6(int) Constant 1
-              92:      6(int) Constant 2
-              93:      6(int) Constant 3
-              94:   28(float) Constant 1056964608
+82(gl_CullMaskEXT):     57(ptr) Variable Input
+              84:             TypeAccelerationStructureKHR
+              85:             TypePointer UniformConstant 84
+      86(accEXT):     85(ptr) Variable UniformConstant
+              88:      6(int) Constant 0
+              89:      6(int) Constant 1
+              90:      6(int) Constant 2
+              91:      6(int) Constant 3
+              92:   28(float) Constant 1056964608
+              93:   29(fvec3) ConstantComposite 92 92 92
+              94:   28(float) Constant 1065353216
               95:   29(fvec3) ConstantComposite 94 94 94
-              96:   28(float) Constant 1065353216
-              97:   29(fvec3) ConstantComposite 96 96 96
-              98:   28(float) Constant 1061158912
-              99:     16(int) Constant 1
-             100:             TypePointer IncomingRayPayloadKHR 72(fvec4)
-101(incomingPayload):    100(ptr) Variable IncomingRayPayloadKHR
-             102:             TypePointer RayPayloadKHR 72(fvec4)
-103(localPayload):    102(ptr) Variable RayPayloadKHR
+              96:   28(float) Constant 1061158912
+              97:     16(int) Constant 1
+              98:             TypePointer IncomingRayPayloadKHR 72(fvec4)
+99(incomingPayload):     98(ptr) Variable IncomingRayPayloadKHR
+             100:             TypePointer RayPayloadKHR 72(fvec4)
+101(localPayload):    100(ptr) Variable RayPayloadKHR
          4(main):           2 Function None 3
                5:             Label
            9(v0):      8(ptr) Variable Function
@@ -154,8 +148,8 @@ spv.ext.ClosestHitShader.rchit
          66(v14):     61(ptr) Variable Function
          69(v15):     17(ptr) Variable Function
          75(v16):     74(ptr) Variable Function
-         79(v17):     74(ptr) Variable Function
-         83(v18):     55(ptr) Variable Function
+         78(v17):     74(ptr) Variable Function
+         81(v18):     55(ptr) Variable Function
               12:    7(ivec3) Load 11(gl_LaunchIDEXT)
                               Store 9(v0) 12
               15:    7(ivec3) Load 14(gl_LaunchSizeEXT)
@@ -188,15 +182,15 @@ spv.ext.ClosestHitShader.rchit
                               Store 66(v14) 68
               71:     16(int) Load 70(gl_GeometryIndexEXT)
                               Store 69(v15) 71
-              77:          60 Load 76(gl_ObjectToWorld3x4EXT)
-              78:          73 Transpose 77
-                              Store 75(v16) 78
-              81:          60 Load 80(gl_WorldToObject3x4EXT)
-              82:          73 Transpose 81
-                              Store 79(v17) 82
-              85:      6(int) Load 84(gl_CullMaskEXT)
-                              Store 83(v18) 85
-              89:          86 Load 88(accEXT)
-                              TraceRayKHR 89 90 91 92 93 90 95 94 97 98 101(incomingPayload)
+              76:          60 Load 64(gl_ObjectToWorldEXT)
+              77:          73 Transpose 76
+                              Store 75(v16) 77
+              79:          60 Load 67(gl_WorldToObjectEXT)
+              80:          73 Transpose 79
+                              Store 78(v17) 80
+              83:      6(int) Load 82(gl_CullMaskEXT)
+                              Store 81(v18) 83
+              87:          84 Load 86(accEXT)
+                              TraceRayKHR 87 88 89 90 91 88 93 92 95 96 99(incomingPayload)
                               Return
                               FunctionEnd

Test/baseResults/spv.ext.IntersectShader.rint.out

@@ -1,7 +1,7 @@
 spv.ext.IntersectShader.rint
 // Module Version 10400
 // Generated by (magic number): 8000a
-// Id's are bound by 86
+// Id's are bound by 84
 
                               Capability RayTracingKHR
                               Capability RayCullMaskKHR
@@ -9,7 +9,7 @@ spv.ext.IntersectShader.rint
                               Extension  "SPV_KHR_ray_tracing"
                1:             ExtInstImport  "GLSL.std.450"
                               MemoryModel Logical GLSL450
-                              EntryPoint IntersectionKHR 4  "main" 11 14 20 23 26 33 36 39 42 47 50 56 59 65 69 75 78
+                              EntryPoint IntersectionKHR 4  "main" 11 14 20 23 26 33 36 39 42 47 50 56 59 73 76
                               Source GLSL 460
                               SourceExtension  "GL_EXT_ray_cull_mask"
                               SourceExtension  "GL_EXT_ray_tracing"
@@ -41,12 +41,10 @@ spv.ext.IntersectShader.rint
                               Name 58  "v12"
                               Name 59  "gl_WorldToObjectEXT"
                               Name 64  "v13"
-                              Name 65  "gl_ObjectToWorld3x4EXT"
-                              Name 68  "v14"
-                              Name 69  "gl_WorldToObject3x4EXT"
-                              Name 73  "v15"
-                              Name 75  "gl_CullMaskEXT"
-                              Name 78  "iAttr"
+                              Name 67  "v14"
+                              Name 71  "v15"
+                              Name 73  "gl_CullMaskEXT"
+                              Name 76  "iAttr"
                               Decorate 11(gl_LaunchIDEXT) BuiltIn LaunchIdKHR
                               Decorate 14(gl_LaunchSizeEXT) BuiltIn LaunchSizeKHR
                               Decorate 20(gl_PrimitiveID) BuiltIn PrimitiveId
@@ -62,9 +60,7 @@ spv.ext.IntersectShader.rint
                               Decorate 50(gl_RayTmaxEXT) Coherent
                               Decorate 56(gl_ObjectToWorldEXT) BuiltIn ObjectToWorldKHR
                               Decorate 59(gl_WorldToObjectEXT) BuiltIn WorldToObjectKHR
-                              Decorate 65(gl_ObjectToWorld3x4EXT) BuiltIn ObjectToWorldKHR
-                              Decorate 69(gl_WorldToObject3x4EXT) BuiltIn WorldToObjectKHR
-                              Decorate 75(gl_CullMaskEXT) BuiltIn CullMaskKHR
+                              Decorate 73(gl_CullMaskEXT) BuiltIn CullMaskKHR
                2:             TypeVoid
                3:             TypeFunction 2
                6:             TypeInt 32 0
@@ -99,19 +95,17 @@ spv.ext.IntersectShader.rint
               61:             TypeVector 28(float) 4
               62:             TypeMatrix 61(fvec4) 3
               63:             TypePointer Function 62
-65(gl_ObjectToWorld3x4EXT):     55(ptr) Variable Input
-69(gl_WorldToObject3x4EXT):     55(ptr) Variable Input
-              72:             TypePointer Function 6(int)
-              74:             TypePointer Input 6(int)
-75(gl_CullMaskEXT):     74(ptr) Variable Input
-              77:             TypePointer HitAttributeKHR 61(fvec4)
-       78(iAttr):     77(ptr) Variable HitAttributeKHR
-              79:   28(float) Constant 1056964608
-              80:   28(float) Constant 0
-              81:   28(float) Constant 1065353216
-              82:   61(fvec4) ConstantComposite 79 79 80 81
-              83:      6(int) Constant 1
-              84:             TypeBool
+              70:             TypePointer Function 6(int)
+              72:             TypePointer Input 6(int)
+73(gl_CullMaskEXT):     72(ptr) Variable Input
+              75:             TypePointer HitAttributeKHR 61(fvec4)
+       76(iAttr):     75(ptr) Variable HitAttributeKHR
+              77:   28(float) Constant 1056964608
+              78:   28(float) Constant 0
+              79:   28(float) Constant 1065353216
+              80:   61(fvec4) ConstantComposite 77 77 78 79
+              81:      6(int) Constant 1
+              82:             TypeBool
          4(main):           2 Function None 3
                5:             Label
            9(v0):      8(ptr) Variable Function
@@ -128,8 +122,8 @@ spv.ext.IntersectShader.rint
          54(v11):     53(ptr) Variable Function
          58(v12):     53(ptr) Variable Function
          64(v13):     63(ptr) Variable Function
-         68(v14):     63(ptr) Variable Function
-         73(v15):     72(ptr) Variable Function
+         67(v14):     63(ptr) Variable Function
+         71(v15):     70(ptr) Variable Function
               12:    7(ivec3) Load 11(gl_LaunchIDEXT)
                               Store 9(v0) 12
               15:    7(ivec3) Load 14(gl_LaunchSizeEXT)
@@ -156,15 +150,15 @@ spv.ext.IntersectShader.rint
                               Store 54(v11) 57
               60:          52 Load 59(gl_WorldToObjectEXT)
                               Store 58(v12) 60
-              66:          52 Load 65(gl_ObjectToWorld3x4EXT)
-              67:          62 Transpose 66
-                              Store 64(v13) 67
-              70:          52 Load 69(gl_WorldToObject3x4EXT)
-              71:          62 Transpose 70
-                              Store 68(v14) 71
-              76:      6(int) Load 75(gl_CullMaskEXT)
-                              Store 73(v15) 76
-                              Store 78(iAttr) 82
-              85:    84(bool) ReportIntersectionKHR 79 83
+              65:          52 Load 56(gl_ObjectToWorldEXT)
+              66:          62 Transpose 65
+                              Store 64(v13) 66
+              68:          52 Load 59(gl_WorldToObjectEXT)
+              69:          62 Transpose 68
+                              Store 67(v14) 69
+              74:      6(int) Load 73(gl_CullMaskEXT)
+                              Store 71(v15) 74
+                              Store 76(iAttr) 80
+              83:    82(bool) ReportIntersectionKHR 77 81
                               Return
                               FunctionEnd