Add IGC option to make it use VISA variable id when constructing name of VISA

variables. This helps map each VISA variable with corresponding entry in dbg file when debugging.

Author: pratikashar

IGC/Compiler/CISACodeGen/CVariable.hpp

@@ -269,6 +269,8 @@ namespace IGC {
         // This accesses the name via a const char *.  This will return
         // nullptr if names are not tracked (e.g. release build).
         const char *getVisaCString() const {
+            if (IGC_IS_FLAG_ENABLED(UseVISAVarNames))
+                return nullptr;
             return m_llvmName.getVisaCString();
         }
 

IGC/common/igc_flags.def

@@ -273,6 +273,7 @@ DECLARE_IGC_REGKEY(bool, EnableRelocations,             false, "Setting this to
 DECLARE_IGC_REGKEY(bool, EnableWriteOldFPToStack,       true,  "Setting this to 1 (true) writes the caller frame's frame-pointer to the start of callee's frame on stack, to support stack walk", false)
 DECLARE_IGC_REGKEY(debugString, ExtraOCLOptions,        0,     "Extra options for OpenCL", true)
 DECLARE_IGC_REGKEY(debugString, ExtraOCLInternalOptions, 0,    "Extra internal options for OpenCL", true)
+DECLARE_IGC_REGKEY(bool, UseVISAVarNames,               false, "Make VISA generate names for virtual variables so they match with dbg file", true)
 
 DECLARE_IGC_GROUP("IGC Features")
 DECLARE_IGC_REGKEY(bool, EnableOCLSIMD16,               true,  "Enable OCL SIMD16 mode", true)