Improve performance when compiling small shaders. (#6396)

Improve performance when compiling small shaders.

Avoid copying witness table entries that are not getting used during linking.
Avoid copying auto-diff related decorations and derivative functions during linking, if the user modules doesn't use autodiff.
Cache operator overload resolution results on global session, so each new Session doesn't need to repetitively run through overload resolution from scratch.

1 files changed, 26 insertions, 0 deletions

diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index e20a4a90f..847c5b55c 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -475,6 +475,31 @@ void calcRequiredLoweringPassSet(
     }
 }
 
+void diagnoseCallStack(IRInst* inst, DiagnosticSink* sink)
+{
+    static const int maxDepth = 5;
+    for (int i = 0; i < maxDepth; i++)
+    {
+        auto func = getParentFunc(inst);
+        if (!func)
+            return;
+        bool shouldContinue = false;
+        for (auto use = func->firstUse; use; use = use->nextUse)
+        {
+            auto user = use->getUser();
+            if (auto call = as<IRCall>(user))
+            {
+                sink->diagnose(call, Diagnostics::seeCallOfFunc, func);
+                inst = call;
+                shouldContinue = true;
+                break;
+            }
+        }
+        if (!shouldContinue)
+            return;
+    }
+}
+
 bool checkStaticAssert(IRInst* inst, DiagnosticSink* sink)
 {
     switch (inst->getOp())
@@ -498,6 +523,7 @@ bool checkStaticAssert(IRInst* inst, DiagnosticSink* sink)
                     {
                         sink->diagnose(inst, Diagnostics::staticAssertionFailureWithoutMessage);
                     }
+                    diagnoseCallStack(inst, sink);
                 }
             }
             else