Update the type of a call inst during specialization. (shader-slang#1569)

Author: csyonghe

source/slang/slang-ir-specialize.cpp

@@ -901,6 +901,12 @@ struct SpecializationContext
         if(!calleeFunc)
             return;
 
+        // Update result type since the callee may have been changed.
+        if (inst->getDataType() != calleeFunc->getResultType())
+        {
+            inst->setFullType(calleeFunc->getResultType());
+        }
+
         // We can only specialize if we have access to a body for the callee.
         //
         if(!calleeFunc->isDefinition())

tests/compute/interface-assoc-type-param.slang

@@ -0,0 +1,60 @@
+// Tests using associated types through an existential-struct-typed param.
+
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -cuda
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -cpu
+
+[anyValueSize(8)]
+interface IInterface
+{
+    associatedtype TEval:IEval;
+    TEval getEval();
+}
+
+[anyValueSize(8)]
+interface IEval
+{
+    uint eval();
+}
+
+struct Impl : IInterface
+{
+    uint val;
+    struct TEval : IEval
+    {
+        uint val;
+        uint eval()
+        {
+            return val;
+        }
+    };
+    TEval getEval()
+    {
+        TEval rs;
+        rs.val = val;
+        return rs;
+    }
+};
+
+struct Params
+{
+    StructuredBuffer<IInterface> obj;
+};
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=gOutputBuffer
+RWStructuredBuffer<uint> gOutputBuffer;
+
+void compute(uint tid, Params p)
+{
+    gOutputBuffer[tid] = p.obj[0].getEval().eval();
+}
+
+//TEST_INPUT: entryPointExistentialType Impl
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID,
+//TEST_INPUT:ubuffer(data=[0 0 0 0 1 0], stride=4):name=params.obj
+    uniform Params params)
+{
+	uint tid = dispatchThreadID.x;
+	compute(tid, params);
+}

tests/compute/interface-assoc-type-param.slang.expected.txt

@@ -0,0 +1,4 @@
+1
+1
+1
+1