Run GEP Loop Strength Reduction pass after LICM with optional

IGC flag

1) Adds new flag RunGEPLSRAfterLICM to run GEP LSR pass after first LICM
   pass (default=false).
2) Makes all GEP LSR's flags available in release build.

Author: pkwasnie-intel

IGC/Compiler/CISACodeGen/ShaderCodeGen.cpp

@@ -1473,17 +1473,19 @@ void OptimizeIR(CodeGenContext* const pContext)
                 mpm.add(llvm::createLCSSAPass());
                 mpm.add(llvm::createLoopSimplifyPass());
 
-                if (IGC_IS_FLAG_ENABLED(EnableGEPLSR) &&
+                bool allowLICM = IGC_IS_FLAG_ENABLED(allowLICM) && pContext->m_retryManager.AllowLICM();
+                bool runGEPLSR = IGC_IS_FLAG_ENABLED(EnableGEPLSR) &&
                     pContext->type == ShaderType::OPENCL_SHADER &&
                     pContext->platform.getPlatformInfo().eProductFamily == IGFX_PVC &&
                     !useStatelessToStateful(*pContext) &&
-                    pContext->m_retryManager.IsFirstTry())
+                    pContext->m_retryManager.IsFirstTry();
+
+                if (runGEPLSR && IGC_IS_FLAG_DISABLED(RunGEPLSRAfterLICM))
                 {
-                    mpm.add(createGEPLoopStrengthReductionPass(IGC_IS_FLAG_ENABLED(allowLICM) &&
-                            pContext->m_retryManager.AllowLICM()));
+                    mpm.add(createGEPLoopStrengthReductionPass(allowLICM));
                 }
 
-                if (IGC_IS_FLAG_ENABLED(allowLICM) && pContext->m_retryManager.AllowLICM())
+                if (allowLICM)
                 {
                     mpm.add(createSpecialCasesDisableLICM());
                     int licmTh = IGC_GET_FLAG_VALUE(LICMStatThreshold);
@@ -1496,6 +1498,11 @@ void OptimizeIR(CodeGenContext* const pContext)
                     mpm.add(new InstrStatistic(pContext, LICM_STAT, InstrStatStage::END, licmTh));
                 }
 
+                if (runGEPLSR && IGC_IS_FLAG_ENABLED(RunGEPLSRAfterLICM))
+                {
+                    mpm.add(createGEPLoopStrengthReductionPass(allowLICM));
+                }
+
 
                 if (!pContext->m_retryManager.IsFirstTry())
                 {
@@ -1546,7 +1553,7 @@ void OptimizeIR(CodeGenContext* const pContext)
                 // LoopUnroll and LICM.
                 mpm.add(createBarrierNoopPass());
 
-                if (IGC_IS_FLAG_ENABLED(allowLICM) && pContext->m_retryManager.AllowLICM())
+                if (allowLICM)
                 {
                     mpm.add(createSpecialCasesDisableLICM());
 #if LLVM_VERSION_MAJOR >= 14

IGC/common/igc_flags.h

@@ -288,9 +288,10 @@ DECLARE_IGC_REGKEY(bool, ForceHoistDp3,              false,   "force dp3 Hoistin
 DECLARE_IGC_REGKEY(bool, EnableBitcastedLoadNarrowing, false, "Enable narrowing of vector loads in bitcasts patterns.", false)
 DECLARE_IGC_REGKEY(bool, EnableBitcastedLoadNarrowingToScalar, false, "Enable narrowing of vector loads to scalar ones in bitcasts patterns.", false)
 DECLARE_IGC_REGKEY(bool, EnableOptReportLoadNarrowing, false, "Generate opt report for narrowing of vector loads.", false)
-DECLARE_IGC_REGKEY(bool, EnableGEPLSR, true, "Enables GEP Loop Strength Reduction pass", false)
-DECLARE_IGC_REGKEY(DWORD, GEPLSRThresholdRatio, 100, "Ratio for register pressure threshold in GEP Loop Strength Reduction pass", false)
-DECLARE_IGC_REGKEY(bool, EnableGEPLSRToPreheader, true, "Enables reduction to loop's preheader in GEP Loop Strength Reduction pass", false)
+DECLARE_IGC_REGKEY(bool, EnableGEPLSR, true, "Enables GEP Loop Strength Reduction pass", true)
+DECLARE_IGC_REGKEY(bool, RunGEPLSRAfterLICM, false, "Runs GEP Loop Strength Reduction pass after first LICM", true)
+DECLARE_IGC_REGKEY(DWORD, GEPLSRThresholdRatio, 100, "Ratio for register pressure threshold in GEP Loop Strength Reduction pass", true)
+DECLARE_IGC_REGKEY(bool, EnableGEPLSRToPreheader, true, "Enables reduction to loop's preheader in GEP Loop Strength Reduction pass", true)
 DECLARE_IGC_REGKEY(bool, EnableGEPLSRAnyIntBitWidth, false, "Experimental: Enables reduction of SCEV with illegal integers. Requires legalization pass to clear up expanded code.", true)
 DECLARE_IGC_REGKEY(DWORD, FPRoundingModeCoalescingMaxDistance, 20, "Max distance in instructions for reordering FP instructions with common rounding mode", false)
 DECLARE_IGC_REGKEY(bool, DisableDotAddToDp4aMerge, false, "Disable Dot and Add ops to Dp4a merge optimization.", false)