spirv: Support initializers on uniforms

If a uniform has an initializer it will now be given as the optional initializer operand to the OpVariable instruction. Fixes: KhronosGroup#1259 Signed-off-by: Neil Roberts <nroberts@igalia.com> (the code) Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com> (the tests)
Igalia · Mar 15, 2019 · f953a02 · f953a02
1 parent f925eef
commit f953a02
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Showing 6 changed files with 61 additions and 3 deletions.
diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
@@ -2996,7 +2996,18 @@ spv::Id TGlslangToSpvTraverser::createSpvVariable(const glslang::TIntermSymbol*
     if (glslang::IsAnonymous(name))
         name = "";
 
-    return builder.createVariable(storageClass, spvType, name);
+    spv::Id initializer = spv::NoResult;
+
+    if (node->getType().getQualifier().storage == glslang::EvqUniform &&
+        !node->getConstArray().empty()) {
+            int nextConst = 0;
+            initializer = createSpvConstantFromConstUnionArray(node->getType(),
+                                                               node->getConstArray(),
+                                                               nextConst,
+                                                               false /* specConst */);
+    }
+
+    return builder.createVariable(storageClass, spvType, name, initializer);
 }
 
 // Return type Id of the sampled type.

diff --git a/SPIRV/SpvBuilder.cpp b/SPIRV/SpvBuilder.cpp
@@ -1306,7 +1306,7 @@ void Builder::makeDiscard()
 }
 
 // Comments in header
-Id Builder::createVariable(StorageClass storageClass, Id type, const char* name)
+Id Builder::createVariable(StorageClass storageClass, Id type, const char* name, Id initializer)
 {
     Id pointerType = makePointer(storageClass, type);
     Instruction* inst = new Instruction(getUniqueId(), pointerType, OpVariable);
@@ -1327,6 +1327,9 @@ Id Builder::createVariable(StorageClass storageClass, Id type, const char* name)
     if (name)
         addName(inst->getResultId(), name);
 
+    if (initializer != NoResult)
+        inst->addIdOperand(initializer);
+
     return inst->getResultId();
 }
 

diff --git a/SPIRV/SpvBuilder.h b/SPIRV/SpvBuilder.h
@@ -300,7 +300,7 @@ class Builder {
     void makeDiscard();
 
     // Create a global or function local or IO variable.
-    Id createVariable(StorageClass, Id type, const char* name = 0);
+    Id createVariable(StorageClass, Id type, const char* name = 0, Id initializer = NoResult);
 
     // Create an intermediate with an undefined value.
     Id createUndefined(Id type);

diff --git a/Test/baseResults/spv.uniformInitializer.frag.out b/Test/baseResults/spv.uniformInitializer.frag.out
@@ -0,0 +1,33 @@
+spv.uniformInitializer.frag
+// Module Version 10000
+// Generated by (magic number): 80007
+// Id's are bound by 16
+
+                              Capability Shader
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main" 9
+                              ExecutionMode 4 OriginLowerLeft
+                              Source GLSL 450
+                              Name 4  "main"
+                              Name 9  "color"
+                              Name 14  "in_color"
+                              Decorate 9(color) Location 0
+                              Decorate 14(in_color) Location 0
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+               7:             TypeVector 6(float) 4
+               8:             TypePointer Output 7(fvec4)
+        9(color):      8(ptr) Variable Output
+              10:    6(float) Constant 0
+              11:    6(float) Constant 1065353216
+              12:    7(fvec4) ConstantComposite 10 11 10 11
+              13:             TypePointer UniformConstant 7(fvec4)
+    14(in_color):     13(ptr) Variable UniformConstant 12
+         4(main):           2 Function None 3
+               5:             Label
+              15:    7(fvec4) Load 14(in_color)
+                              Store 9(color) 15
+                              Return
+                              FunctionEnd
diff --git a/Test/spv.uniformInitializer.frag b/Test/spv.uniformInitializer.frag
@@ -0,0 +1,10 @@
+#version 450
+
+layout (location = 0) out vec4 color;
+
+layout (location = 0) uniform vec4 in_color = vec4(0.0, 1.0, 0.0, 1.0);
+
+void main()
+{
+	color = in_color;
+}
diff --git a/gtests/Spv.FromFile.cpp b/gtests/Spv.FromFile.cpp
@@ -490,6 +490,7 @@ INSTANTIATE_TEST_CASE_P(
         "spv.rankShift.comp",
         "spv.specConst.vert",
         "spv.OVR_multiview.vert",
+        "spv.uniformInitializer.frag",
         "spv.xfbOffsetOnBlockMembersAssignment.vert",
         "spv.xfbOffsetOnStructMembersAssignment.vert",
         "spv.xfbOverlapOffsetCheckWithBlockAndMember.vert",