Bug fixes to enable function pointers directly passed by FE (Commit attempt #3)

Author: dlei6g

IGC/AdaptorCommon/ProcessFuncAttributes.cpp

@@ -322,8 +322,10 @@ bool ProcessFuncAttributes::runOnModule(Module& M)
         for (auto I : F->users()) {
             if (CallInst* callInst = dyn_cast<CallInst>(&*I)) {
                 // Go through call sites and remove NoInline atrributes.
+                // Verifier fails if a call has optnone but not noinline, so if we remove noinline, we must also remove optnone
                 if (callInst->hasFnAttr(llvm::Attribute::NoInline)) {
                     callInst->removeAttribute(AttributeList::FunctionIndex, llvm::Attribute::NoInline);
+                    callInst->removeAttribute(AttributeList::FunctionIndex, llvm::Attribute::OptimizeNone);
                 }
                 // Remove AlwaysInline at callsites
                 if (isOptDisable && callInst->hasFnAttr(llvm::Attribute::AlwaysInline)) {

IGC/Compiler/Optimizer/OpenCLPasses/DeviceEnqueueFuncs/TransformBlocks.cpp

@@ -1635,7 +1635,10 @@ namespace //Anonymous
                 }
             }
 
-            // remove function pointers
+            // Remove function pointer from instructions
+            // FIXME: Allowing function pointer calls directly passed by FE will cause regressions due to implicit args
+            // not being supported by indirect calls. When runtime turns on support, we should remove the following code
+            // to allow function pointer usage in all cases.
             auto nullPtrConst = llvm::ConstantPointerNull::get(Type::getInt8PtrTy(M.getContext()));
             for (auto& func : M.functions())
             {
@@ -1645,11 +1648,8 @@ namespace //Anonymous
                     {
                         if (!isa<llvm::Constant>(user)) {
                             user->replaceUsesOfWith(&func, nullPtrConst);
+                            changed = true;
                         }
-                        else {
-                            user->replaceAllUsesWith(llvm::Constant::getNullValue(user->getType()));
-                        }
-                        changed = true;
                     }
                 }
             }
@@ -2153,7 +2153,7 @@ namespace //Anonymous
         {
             return std::unique_ptr<StructValue>(new NullStructValue(sourceValue));
         }
-        IGC_ASSERT_MESSAGE(0, "should not be here");
+        // Not a block description struct
         return nullptr;
     }
 

IGC/Compiler/Optimizer/OpenCLPasses/ProgramScopeConstants/ProgramScopeConstantAnalysis.cpp

@@ -485,7 +485,8 @@ void ProgramScopeConstantAnalysis::addData(Constant* initializer,
                     if (Constant * C = dyn_cast<Constant>(&Op))
                         addData(C, inlineProgramScopeBuffer, pointerOffsetInfoList, inlineProgramScopeOffsets, addressSpace);
             }
-            else if (ce->getOpcode() == Instruction::AddrSpaceCast)
+            else if (ce->getOpcode() == Instruction::AddrSpaceCast ||
+                ce->getOpcode() == Instruction::BitCast)
             {
                 if (Constant * C = dyn_cast<Constant>(ce->getOperand(0)))
                     addData(C, inlineProgramScopeBuffer, pointerOffsetInfoList, inlineProgramScopeOffsets, addressSpace);