Fix outdated comment.

Author: pratikashar

IGC/Compiler/CISACodeGen/DebugInfo.cpp

@@ -300,7 +300,7 @@ void DebugInfoPass::EmitDebugInfo(bool finalize, DbgDecoder* decodedDbg,
 
 
 // Mark privateBase aka ImplicitArg::PRIVATE_BASE as Output for debugging
-void DebugInfoData::markOutputPrivateBase(CShader* pShader)
+void DebugInfoData::markOutputPrivateBase(CShader* pShader, IDebugEmitter* pDebugEmitter)
 {
     IGC_ASSERT_MESSAGE(IGC_IS_FLAG_ENABLED(UseOffsetInLocation), "UseOffsetInLocation not enabled");
 
@@ -309,6 +309,9 @@ void DebugInfoData::markOutputPrivateBase(CShader* pShader)
         CVariable* pVar = pShader->GetPrivateBase();
         if (pVar)
         {
+            // cache privateBase as it may be destroyed if subroutine
+            // is emitted.
+            pDebugEmitter->getCurrentVISA()->setPrivateBaseReg(pVar);
             pShader->GetEncoder().GetVISAKernel()->AddAttributeToVar(pVar->visaGenVariable[0], "Output", 0, nullptr);
             if (pShader->m_dispatchSize == SIMDMode::SIMD32 && pVar->visaGenVariable[1])
             {
@@ -377,7 +380,14 @@ void DebugInfoData::markOutput(llvm::Function& F, CShader* pShader, IDebugEmitte
                 // Per Thread Offset non-debug instruction must have 'Output' attribute
                 // added in the function to be called.
                 markOutputVar(pShader, pDebugEmitter, &pInst, "perThreadOffset");
-                markOutputPrivateBase(pShader); // Mark privateBase aka ImplicitArg::PRIVATE_BASE as Output for debugging
+                if (F.getCallingConv() == CallingConv::SPIR_KERNEL)
+                {
+                    markOutputPrivateBase(pShader, pDebugEmitter); // Mark privateBase aka ImplicitArg::PRIVATE_BASE as Output for debugging
+                }
+                else
+                {
+                    // TODO: Apply privateBase of kernel to SPIR_FUNC if its a subroutine
+                }
                 ScalarVisaModule* scVISAModule = (ScalarVisaModule*)visaModule;
                 IGC_ASSERT_MESSAGE(scVISAModule->getPerThreadOffset()==nullptr, "setPerThreadOffset was set earlier");
                 scVISAModule->setPerThreadOffset(&pInst);

IGC/Compiler/CISACodeGen/DebugInfo.hpp

@@ -64,7 +64,7 @@ namespace IGC
         CShader* m_pShader = nullptr;
         IDebugEmitter* m_pDebugEmitter = nullptr;
 
-        static void markOutputPrivateBase(CShader* pShader);
+        static void markOutputPrivateBase(CShader* pShader, IDebugEmitter* pDebugEmitter);
         static void markOutputVar(CShader* pShader, IDebugEmitter* pDebugEmitter, llvm::Instruction* pInst, const char* pMetaDataName);
         static void markOutput(llvm::Function& F, CShader* pShader, IDebugEmitter* pDebugEmitter);
 

IGC/Compiler/DebugInfo/ScalarVISAModule.h

@@ -60,7 +60,7 @@ class ScalarVisaModule final : public IGC::VISAModule {
       return isLineTableOnly(m_pShader);
     }
     unsigned getPrivateBaseReg() const override {
-      auto pVar = m_pShader->GetPrivateBase();
+      auto pVar = privateBase;
       unsigned privateBaseRegNum = m_pShader->GetEncoder().GetVISAKernel()->getDeclarationID(pVar->visaGenVariable[0]);
       return privateBaseRegNum;
     }
@@ -141,6 +141,13 @@ class ScalarVisaModule final : public IGC::VISAModule {
 
     llvm::StringRef GetVISAFuncName(llvm::StringRef OldName) const override;
 
+    void setPrivateBaseReg(void* V) override
+    {
+        privateBase = (IGC::CVariable*)V;
+    }
+
+    void* getPrivateBase() override { return privateBase; }
+
 private:
     /// @brief Constructor.
     /// @param m_pShader holds the processed entry point function and generated VISA code.
@@ -155,6 +162,7 @@ class ScalarVisaModule final : public IGC::VISAModule {
     CShader* m_pShader;
     CVariable* m_framePtr = nullptr;
     llvm::Instruction* m_perThreadOffset = nullptr;
+    CVariable* privateBase = nullptr;
 };
 
 }

IGC/DebugInfo/VISAModule.hpp

@@ -500,6 +500,8 @@ namespace IGC
         virtual unsigned getNumGRFs() const = 0;
         virtual unsigned getPointerSize() const = 0;
 
+        virtual void* getPrivateBase() = 0;
+        virtual void setPrivateBaseReg(void*) = 0;
         virtual bool hasPTO() const = 0;
         virtual int getPTOReg() const = 0;
         virtual int getFPReg() const = 0;

IGC/VectorCompiler/lib/GenXCodeGen/GenXDebugInfo.cpp

@@ -317,6 +317,9 @@ class GenXFunction final : public IGC::VISAModule {
   }
   uint16_t GetSIMDSize() const override { return 1; }
 
+  void* getPrivateBase() override { return nullptr; };
+  void setPrivateBaseReg(void*) override {};
+
   bool hasPTO() const override { return false; }
   int getPTOReg() const override { return -1; }
   int getFPReg() const override { return -1; }