[Autobackout][FuncReg]Revert of change: 3279638

 Improve static analysis

Improve static analysis

Author: tmpark

IGC/Compiler/CISACodeGen/EmitVISAPass.cpp

@@ -1150,7 +1150,9 @@ bool EmitPass::runOnFunction(llvm::Function& F)
                 };
 
                 if (IGC_IS_FLAG_ENABLED(StaticProfileGuidedSpillCostAnalysis) &&
-                    llvmInst->isTerminator() && hasBlockFreq(llvmInst)) {
+                    llvmInst->isTerminator()) {
+                    IGC_ASSERT(hasBlockFreq(
+                        llvmInst)); // terminator should have freeq info
                     auto getFreqDigit = [&](Instruction *inst) {
                       MDNode *mn_digits =
                           llvmInst->getMetadata("stats.blockFrequency.digits");

IGC/common/igc_flags.h

@@ -648,9 +648,9 @@ DECLARE_IGC_REGKEY(DWORD, ParameterForColdFuncThreshold,        80, "C/10-STD fo
 DECLARE_IGC_REGKEY(bool, ControlUnitSize,               false, "Control compilation unit size by unit trimming", true)
 DECLARE_IGC_REGKEY(DWORD, ExpandedUnitSizeThreshold,    50000, "Trimming target of compilation unit size", true)
 DECLARE_IGC_REGKEY(DWORD, PrintControlUnitSize,             0, "Print information about unit trimming", true)
-DECLARE_IGC_REGKEY(bool, StaticProfileGuidedSpillCostAnalysis,  true, "Use static profile information to estimate spill cost", true)
+DECLARE_IGC_REGKEY(bool, StaticProfileGuidedSpillCostAnalysis,  false, "Use static profile information to estimate spill cost", true)
 DECLARE_IGC_REGKEY(DWORD, StaticProfileGuidedSpillCostAnalysisScale, 4, "Scale adjustment for static profile guided spill cost analysis", true)
-DECLARE_IGC_REGKEY(DWORD, StaticProfileGuidedSpillCostAnalysisFunc, 0, "Spill cost function where 0 is based on a new spill cost and 1 the existing one", true)
+DECLARE_IGC_REGKEY(DWORD, StaticProfileGuidedSpillCostAnalysisFunc, 2, "Normalization factor for too low frequency lower than C/1000", true)
 DECLARE_IGC_REGKEY(DWORD, PrintStaticProfileGuidedSpillCostAnalysis,        0, "Print debug messages for profile embedding", true)
 DECLARE_IGC_REGKEY(bool, EnableConstantPromotion,       true, "Enable global constant data to register promotion", false)
 DECLARE_IGC_REGKEY(bool, AllowNonLoopConstantPromotion, false, "Allows promotion for constants not in loop (e.g. used once)", false)

visa/FrequencyInfo.cpp

@@ -299,7 +299,7 @@ void FrequencyInfo::computeFreqSpillCosts(GlobalRA &gra,
           if (costFunc == 1) {
             metric = 2;
             // address or flag variables
-            spillCost = std::sqrt((float)refFreqDouble) * refCount * refCount *
+            spillCost = (float)std::sqrt(refFreqDouble) * refCount * refCount *
                         byteSize * // 1.0f * refCount * refCount * byteSize *
                         (float)sqrt(byteSize) /
                         ((float)sqrt(degree) * (float)(sqrt(sqrt(numRows))));