Disable spill compaction in retry

Disable spill compaction in retry

Author: jaladreips

IGC/Compiler/CodeGenContext.cpp

@@ -36,13 +36,14 @@ namespace IGC
         bool allowLargeGRF;
         bool allowLoadSinking;
         bool forceIndirectCallsInSyncRT;
+        bool allowRaytracingSpillCompaction;
         unsigned nextState;
     };
 
     static const RetryState RetryTable[] = {
-       // adrCl  licm   codSk AdrSk  Slice  PrivM  VISAP  URBWr  Coals  GRF    loadSk, SyncRT
-        { false, true,  true, false, false, true,  true,  true,  true,  false, false,  false, 1 },
-        { true,  false, true, true,  true,  false, false, false, false, true,  true,   true, 500 }
+       // adrCl  licm   codSk AdrSk  Slice  PrivM  VISAP  URBWr  Coals  GRF    loadSk, SyncRT, compactspills
+        { false, true,  true, false, false, true,  true,  true,  true,  false, false,  false,  true,         1 },
+        { true,  false, true, true,  true,  false, false, false, false, true,  true,   true,   false,        500 }
     };
 
     static constexpr size_t RetryTableSize = sizeof(RetryTable) / sizeof(RetryState);
@@ -162,6 +163,16 @@ namespace IGC
         return RetryTable[id].forceIndirectCallsInSyncRT;
     }
 
+    bool RetryManager::AllowRaytracingSpillCompaction() const
+    {
+        if (IGC_IS_FLAG_ENABLED(AllowSpillCompactionOnRetry)) // allow spill compaction on retry
+            return true;
+
+        unsigned id = GetRetryId();
+        IGC_ASSERT(id < RetryTableSize);
+        return RetryTable[id].allowRaytracingSpillCompaction;
+    }
+
     bool RetryManager::AllowLoadSinking(Function* F) const
     {
         unsigned id = GetPerFuncRetryStateId(F);

IGC/Compiler/CodeGenPublic.h

@@ -776,6 +776,7 @@ namespace IGC
         bool AllowConstantCoalescing(llvm::Function* F = nullptr) const;
         bool AllowLargeGRF(llvm::Function* F = nullptr) const;
         bool ForceIndirectCallsInSyncRT() const;
+        bool AllowRaytracingSpillCompaction() const;
         bool AllowLoadSinking(llvm::Function* F = nullptr) const;
         void SetFirstStateId(int id);
         bool IsFirstTry() const;

IGC/common/igc_flags.h

@@ -962,6 +962,7 @@ DECLARE_IGC_GROUP("Raytracing Options")
     DECLARE_IGC_REGKEY(bool, DisableLateRemat, false, "Disable quick remats to avoid some spills", true)
     DECLARE_IGC_REGKEY(DWORD, RematThreshold, 6, "Tunes how aggresively we should remat values into continuations", true)
     DECLARE_IGC_REGKEY(bool, DisableCompactifySpills, false, "Just emit spill/fill at the point of def/use", true)
+    DECLARE_IGC_REGKEY(bool, AllowSpillCompactionOnRetry, false, "Allow spill compaction on retry - may increase spills", true)
     DECLARE_IGC_REGKEY(bool, EnableHoistRemat, false, "Hoist rematerialized instructions to shader entry. Longer live ranges but common values fused.", true)
     DECLARE_IGC_REGKEY(bool, DisableRTGlobalsKnownValues, false, "load MaxBVHLevels from RTGlobals rather than assumming = 2", true)
     DECLARE_IGC_REGKEY(bool, DisableRaytracingIntrinsicAttributes, false, "Turn off noalias and dereferenceable attributes", true)