Library compilations cannot use scratch space for private memory

SS Private memory is disabled for when stackcalls are enabled, including indirect calls.
However when a module is compiled as a library, i.e. there is no kernel function, only external-linkage library functions, we fail to detect that module as having a stackcall.
In this case we need to disable SS private memory as well since the dynamically linked callers will also have it disabled.

Author: dlei6g

IGC/Compiler/CISACodeGen/GenCodeGenModule.cpp

@@ -654,11 +654,9 @@ void GenXFunctionGroupAnalysis::setGroupAttributes()
 void GenXFunctionGroupAnalysis::addIndirectFuncsToKernelGroup(llvm::Module* pModule)
 {
     auto pMdUtils = getAnalysis<MetaDataUtilsWrapper>().getMetaDataUtils();
-    auto IFG = getOrCreateIndirectCallGroup(pModule);
-
-    if (!IFG) return;
 
     // Find all indirectly called functions that require a symbol
+    SmallVector<Function*, 16> indirectFunctions;
     for (auto I = pModule->begin(), E = pModule->end(); I != E; ++I)
     {
         Function* F = &(*I);
@@ -667,6 +665,16 @@ void GenXFunctionGroupAnalysis::addIndirectFuncsToKernelGroup(llvm::Module* pMod
         if (F->hasFnAttribute("referenced-indirectly"))
         {
             IGC_ASSERT(getGroup(F) == nullptr);
+            indirectFunctions.push_back(F);
+        }
+    }
+    // Add them to the indirect call group
+    if (!indirectFunctions.empty())
+    {
+        auto IFG = getOrCreateIndirectCallGroup(pModule);
+        IGC_ASSERT(IFG);
+        for (auto F : indirectFunctions)
+        {
             addToFunctionGroup(F, IFG, F);
         }
     }

IGC/Compiler/Optimizer/OpenCLPasses/PrivateMemory/PrivateMemoryResolution.cpp

@@ -277,11 +277,14 @@ bool PrivateMemoryResolution::safeToUseScratchSpace(llvm::Module& M) const
 
     //
     // Do not use scratch space if module has any stack call.
-    // Do not use scratch space if modeule has any variable length alloca
+    // Do not use scratch space if module has any variable length alloca
+    // Do not use scratch space if module has indirectly called functions
     //
     if (bOCLLegacyStatelessCheck) {
         if (auto * FGA = getAnalysisIfAvailable<GenXFunctionGroupAnalysis>()) {
             if (FGA->getModule() == &M) {
+                if (FGA->getIndirectCallGroup() != nullptr)
+                    return false;
                 for (auto& I : *FGA) {
                     if (I->hasStackCall())
                         return false;