Move assignment rationalization to before the late helper expansion phases (#85585)

* Flags dump for STOREIND

* gtNewAssignNode assert

* Call morphing

* GenTree::GetLayout fixup

* If Conversion

* Tail duplication

* Costing

* Move assignment rationalization before GC Poll insertion

* Block morphing (part 1)

* Block morphing: switch dst<->src around

* Finish block morphing

* Helper expansion phases

* Fix formatting

Author: SingleAccretion

src/coreclr/jit/compiler.cpp

@@ -5031,6 +5031,8 @@ void Compiler::compCompile(void** methodCodePtr, uint32_t* methodCodeSize, JitFl
     optLoopTableValid         = false;
     optLoopsRequirePreHeaders = false;
 
+    DoPhase(this, PHASE_RATIONALIZE_ASSIGNMENTS, &Compiler::fgRationalizeAssignments);
+
 #ifdef DEBUG
     DoPhase(this, PHASE_STRESS_SPLIT_TREE, &Compiler::StressSplitTree);
 #endif
@@ -5069,8 +5071,6 @@ void Compiler::compCompile(void** methodCodePtr, uint32_t* methodCodeSize, JitFl
     //
     DoPhase(this, PHASE_DETERMINE_FIRST_COLD_BLOCK, &Compiler::fgDetermineFirstColdBlock);
 
-    DoPhase(this, PHASE_RATIONALIZE_ASSIGNMENTS, &Compiler::fgRationalizeAssignments);
-
 #ifdef DEBUG
     // Stash the current estimate of the function's size if necessary.
     if (verbose)

src/coreclr/jit/compiler.h

@@ -2536,6 +2536,7 @@ class Compiler
                                                   void*                   compileTimeHandle);
 
     GenTreeLclVar* gtNewLclvNode(unsigned lnum, var_types type DEBUGARG(IL_OFFSET offs = BAD_IL_OFFSET));
+    GenTreeLclVar* gtNewLclVarNode(unsigned lclNum, var_types type = TYP_UNDEF);
     GenTreeLclVar* gtNewLclLNode(unsigned lnum, var_types type DEBUGARG(IL_OFFSET offs = BAD_IL_OFFSET));
 
     GenTreeLclFld* gtNewLclVarAddrNode(unsigned lclNum, var_types type = TYP_I_IMPL);
@@ -2838,6 +2839,12 @@ class Compiler
 
     GenTreeIndir* gtNewIndir(var_types typ, GenTree* addr, GenTreeFlags indirFlags = GTF_EMPTY);
 
+    GenTreeBlk* gtNewStoreBlkNode(
+        ClassLayout* layout, GenTree* addr, GenTree* data, GenTreeFlags indirFlags = GTF_EMPTY);
+
+    GenTreeStoreInd* gtNewStoreIndNode(
+        var_types type, GenTree* addr, GenTree* data, GenTreeFlags indirFlags = GTF_EMPTY);
+
     GenTree* gtNewLoadValueNode(
         var_types type, ClassLayout* layout, GenTree* addr, GenTreeFlags indirFlags = GTF_EMPTY);
 
@@ -2851,6 +2858,14 @@ class Compiler
         return gtNewLoadValueNode(type, nullptr, addr, indirFlags);
     }
 
+    GenTree* gtNewStoreValueNode(
+        var_types type, ClassLayout* layout, GenTree* addr, GenTree* data, GenTreeFlags indirFlags = GTF_EMPTY);
+
+    GenTree* gtNewStoreValueNode(ClassLayout* layout, GenTree* addr, GenTree* data, GenTreeFlags indirFlags = GTF_EMPTY)
+    {
+        return gtNewStoreValueNode(layout->GetType(), layout, addr, data, indirFlags);
+    }
+
     GenTree* gtNewNullCheck(GenTree* addr, BasicBlock* basicBlock);
 
     var_types gtTypeForNullCheck(GenTree* tree);
@@ -2962,6 +2977,9 @@ class Compiler
 
     void gtPrepareCost(GenTree* tree);
     bool gtIsLikelyRegVar(GenTree* tree);
+    void gtGetLclVarNodeCost(GenTreeLclVar* node, int* pCostEx, int* pCostSz, bool isLikelyRegVar);
+    void gtGetLclFldNodeCost(GenTreeLclFld* node, int* pCostEx, int* pCostSz);
+    bool gtGetIndNodeCost(GenTreeIndir* node, int* pCostEx, int* pCostSz);
 
     // Returns true iff the secondNode can be swapped with firstNode.
     bool gtCanSwapOrder(GenTree* firstNode, GenTree* secondNode);

src/coreclr/jit/compiler.hpp

@@ -1230,6 +1230,7 @@ inline void GenTree::SetOper(genTreeOps oper, ValueNumberUpdate vnUpdate)
             break;
 #endif
         case GT_LCL_FLD:
+        case GT_STORE_LCL_FLD:
             AsLclFld()->SetLclOffs(0);
             AsLclFld()->SetLayout(nullptr);
             break;

src/coreclr/jit/decomposelongs.cpp

@@ -514,10 +514,8 @@ GenTree* DecomposeLongs::DecomposeStoreLclFld(LIR::Use& use)
     loStore->gtFlags |= GTF_VAR_USEASG;
 
     // Create the store for the upper half of the GT_LONG and insert it after the low store.
-    GenTreeLclFld* hiStore = m_compiler->gtNewLclFldNode(loStore->GetLclNum(), TYP_INT, loStore->GetLclOffs() + 4);
-    hiStore->SetOper(GT_STORE_LCL_FLD);
-    hiStore->gtOp1 = value->gtOp2;
-    hiStore->gtFlags |= (GTF_VAR_DEF | GTF_VAR_USEASG);
+    GenTreeLclFld* hiStore =
+        m_compiler->gtNewStoreLclFldNode(loStore->GetLclNum(), TYP_INT, loStore->GetLclOffs() + 4, value->gtOp2);
 
     Range().InsertAfter(loStore, hiStore);
 

src/coreclr/jit/fgopt.cpp

@@ -3445,24 +3445,14 @@ bool Compiler::fgBlockEndFavorsTailDuplication(BasicBlock* block, unsigned lclNu
     while (count < limit)
     {
         count++;
+        unsigned       storeLclNum;
         GenTree* const tree = stmt->GetRootNode();
-        if (tree->OperIs(GT_ASG) && !tree->OperIsBlkOp())
+        if (tree->OperIsStoreLcl(&storeLclNum) && (storeLclNum == lclNum) && !tree->OperIsBlkOp())
         {
-            GenTree* const op1 = tree->AsOp()->gtOp1;
-
-            if (op1->IsLocal())
+            GenTree* const data = tree->Data();
+            if (data->OperIsArrLength() || data->OperIsConst() || data->OperIsCompare())
             {
-                const unsigned op1LclNum = op1->AsLclVarCommon()->GetLclNum();
-
-                if (op1LclNum == lclNum)
-                {
-                    GenTree* const op2 = tree->AsOp()->gtOp2;
-
-                    if (op2->OperIsArrLength() || op2->OperIsConst() || op2->OperIsCompare())
-                    {
-                        return true;
-                    }
-                }
+                return true;
             }
         }
 
@@ -3616,36 +3606,29 @@ bool Compiler::fgBlockIsGoodTailDuplicationCandidate(BasicBlock* target, unsigne
     // Otherwise check the first stmt.
     // Verify the branch is just a simple local compare.
     //
+    unsigned       storeLclNum;
     GenTree* const firstTree = firstStmt->GetRootNode();
-
-    if (firstTree->gtOper != GT_ASG)
-    {
-        return false;
-    }
-
-    GenTree* const lhs = firstTree->AsOp()->gtOp1;
-    if (!lhs->OperIs(GT_LCL_VAR))
+    if (!firstTree->OperIsStoreLclVar(&storeLclNum))
     {
         return false;
     }
 
-    const unsigned lhsLcl = lhs->AsLclVarCommon()->GetLclNum();
-    if (lhsLcl != *lclNum)
+    if (storeLclNum != *lclNum)
     {
         return false;
     }
 
     // Could allow unary here too...
     //
-    GenTree* const rhs = firstTree->AsOp()->gtOp2;
-    if (!rhs->OperIsBinary())
+    GenTree* const data = firstTree->Data();
+    if (!data->OperIsBinary())
     {
         return false;
     }
 
     // op1 must be some combinations of casts of local or constant
     // (or unary)
-    op1 = rhs->AsOp()->gtOp1;
+    op1 = data->AsOp()->gtOp1;
     while (op1->gtOper == GT_CAST)
     {
         op1 = op1->AsOp()->gtOp1;
@@ -3658,7 +3641,7 @@ bool Compiler::fgBlockIsGoodTailDuplicationCandidate(BasicBlock* target, unsigne
 
     // op2 must be some combinations of casts of local or constant
     // (or unary)
-    op2 = rhs->AsOp()->gtOp2;
+    op2 = data->AsOp()->gtOp2;
 
     // A binop may not actually have an op2.
     //

src/coreclr/jit/flowgraph.cpp

@@ -2979,6 +2979,7 @@ GenTree* Compiler::fgRationalizeAssignment(GenTreeOp* assignment)
     {
         store->SetReverseOp();
     }
+    store->CopyRawCosts(assignment);
 
     if (storeOp == GT_STOREIND)
     {