Remove GT_STORE_DYN_BLK (#98905)

docs/design/coreclr/jit/first-class-structs.md

@@ -94,10 +94,6 @@ encountered by most phases of the JIT:
       [#21705](https://github.com/dotnet/coreclr/pull/21705) they are no longer large nodes.
   * `GT_STORE_OBJ` and `GT_STORE_BLK` have the same structure as `GT_OBJ` and `GT_BLK`, respectively
     * `Data()` is op2
-  * `GT_STORE_DYN_BLK` (GenTreeStoreDynBlk extends GenTreeBlk)
-    * Additional child `gtDynamicSize`
-    * Note that these aren't really struct stores; they represent dynamically sized blocks
-      of arbitrary data.
   * For `GT_LCL_FLD` nodes, we store a pointer to `ClassLayout` in the node.
   * For `GT_LCL_VAR` nodes, the `ClassLayout` is obtained from the `LclVarDsc`.
 

src/coreclr/jit/assertionprop.cpp

@@ -5493,7 +5493,6 @@ GenTree* Compiler::optAssertionProp(ASSERT_VALARG_TP assertions, GenTree* tree,
         case GT_IND:
         case GT_STOREIND:
         case GT_NULLCHECK:
-        case GT_STORE_DYN_BLK:
             return optAssertionProp_Ind(assertions, tree, stmt);
 
         case GT_BOUNDS_CHECK:

src/coreclr/jit/codegenarmarch.cpp

@@ -513,7 +513,6 @@ void CodeGen::genCodeForTreeNode(GenTree* treeNode)
 #endif
             break;
 
-        case GT_STORE_DYN_BLK:
         case GT_STORE_BLK:
             genCodeForStoreBlk(treeNode->AsBlk());
             break;
@@ -4568,14 +4567,14 @@ void CodeGen::inst_JMP(emitJumpKind jmp, BasicBlock* tgtBlock)
 }
 
 //------------------------------------------------------------------------
-// genCodeForStoreBlk: Produce code for a GT_STORE_DYN_BLK/GT_STORE_BLK node.
+// genCodeForStoreBlk: Produce code for a GT_STORE_BLK node.
 //
 // Arguments:
 //    tree - the node
 //
 void CodeGen::genCodeForStoreBlk(GenTreeBlk* blkOp)
 {
-    assert(blkOp->OperIs(GT_STORE_DYN_BLK, GT_STORE_BLK));
+    assert(blkOp->OperIs(GT_STORE_BLK));
 
     bool isCopyBlk = blkOp->OperIsCopyBlkOp();
 

src/coreclr/jit/codegencommon.cpp

@@ -6546,7 +6546,7 @@ void CodeGen::genDefinePendingCallLabel(GenTreeCall* call)
     // For certain indirect calls we may introduce helper calls before that we need to skip:
     // - CFG may introduce a call to the validator first
     // - Generic virtual methods may compute the target dynamically through a separate helper call
-    // - memset/memcpy helper calls emitted for GT_STORE_DYN_BLK/GT_STORE_BLK
+    // - memset/memcpy helper calls emitted for GT_STORE_BLK
     if (call->IsHelperCall())
     {
         switch (compiler->eeGetHelperNum(call->gtCallMethHnd))

src/coreclr/jit/codegenlinear.cpp

@@ -1935,18 +1935,9 @@ void CodeGen::genSetBlockSize(GenTreeBlk* blkNode, regNumber sizeReg)
 {
     if (sizeReg != REG_NA)
     {
-        unsigned blockSize = blkNode->Size();
-        if (!blkNode->OperIs(GT_STORE_DYN_BLK))
-        {
-            assert((blkNode->gtRsvdRegs & genRegMask(sizeReg)) != 0);
-            // This can go via helper which takes the size as a native uint.
-            instGen_Set_Reg_To_Imm(EA_PTRSIZE, sizeReg, blockSize);
-        }
-        else
-        {
-            GenTree* sizeNode = blkNode->AsStoreDynBlk()->gtDynamicSize;
-            inst_Mov(sizeNode->TypeGet(), sizeReg, sizeNode->GetRegNum(), /* canSkip */ true);
-        }
+        assert((blkNode->gtRsvdRegs & genRegMask(sizeReg)) != 0);
+        // This can go via helper which takes the size as a native uint.
+        instGen_Set_Reg_To_Imm(EA_PTRSIZE, sizeReg, blkNode->Size());
     }
 }
 
@@ -2052,12 +2043,6 @@ void CodeGen::genConsumeBlockOp(GenTreeBlk* blkNode, regNumber dstReg, regNumber
     genConsumeReg(dstAddr);
     // The source may be a local or in a register; 'genConsumeBlockSrc' will check that.
     genConsumeBlockSrc(blkNode);
-    // 'genSetBlockSize' (called below) will ensure that a register has been reserved as needed
-    // in the case where the size is a constant (i.e. it is not GT_STORE_DYN_BLK).
-    if (blkNode->OperGet() == GT_STORE_DYN_BLK)
-    {
-        genConsumeReg(blkNode->AsStoreDynBlk()->gtDynamicSize);
-    }
 
     // Next, perform any necessary moves.
     genCopyRegIfNeeded(dstAddr, dstReg);

src/coreclr/jit/codegenloongarch64.cpp

@@ -5022,7 +5022,6 @@ void CodeGen::genCodeForTreeNode(GenTree* treeNode)
             emit->emitIns_R_L(INS_ld_d, EA_PTRSIZE, genPendingCallLabel, targetReg);
             break;
 
-        case GT_STORE_DYN_BLK:
         case GT_STORE_BLK:
             genCodeForStoreBlk(treeNode->AsBlk());
             break;
@@ -7249,14 +7248,14 @@ void CodeGen::genCreateAndStoreGCInfo(unsigned codeSize,
 }
 
 //------------------------------------------------------------------------
-// genCodeForStoreBlk: Produce code for a GT_STORE_DYN_BLK/GT_STORE_BLK node.
+// genCodeForStoreBlk: Produce code for a GT_STORE_BLK node.
 //
 // Arguments:
 //    tree - the node
 //
 void CodeGen::genCodeForStoreBlk(GenTreeBlk* blkOp)
 {
-    assert(blkOp->OperIs(GT_STORE_DYN_BLK, GT_STORE_BLK));
+    assert(blkOp->OperIs(GT_STORE_BLK));
 
     if (blkOp->gtBlkOpGcUnsafe)
     {

src/coreclr/jit/codegenriscv64.cpp

@@ -5102,7 +5102,6 @@ void CodeGen::genCodeForTreeNode(GenTree* treeNode)
             emit->emitIns_R_L(INS_ld, EA_PTRSIZE, genPendingCallLabel, targetReg);
             break;
 
-        case GT_STORE_DYN_BLK:
         case GT_STORE_BLK:
             genCodeForStoreBlk(treeNode->AsBlk());
             break;
@@ -7246,14 +7245,14 @@ void CodeGen::genCreateAndStoreGCInfo(unsigned codeSize,
 }
 
 //------------------------------------------------------------------------
-// genCodeForStoreBlk: Produce code for a GT_STORE_DYN_BLK/GT_STORE_BLK node.
+// genCodeForStoreBlk: Produce code for a GT_STORE_BLK node.
 //
 // Arguments:
 //    tree - the node
 //
 void CodeGen::genCodeForStoreBlk(GenTreeBlk* blkOp)
 {
-    assert(blkOp->OperIs(GT_STORE_DYN_BLK, GT_STORE_BLK));
+    assert(blkOp->OperIs(GT_STORE_BLK));
 
     if (blkOp->gtBlkOpGcUnsafe)
     {

src/coreclr/jit/codegenxarch.cpp

@@ -2183,7 +2183,6 @@ void CodeGen::genCodeForTreeNode(GenTree* treeNode)
             emit->emitIns_R_L(INS_lea, EA_PTR_DSP_RELOC, genPendingCallLabel, treeNode->GetRegNum());
             break;
 
-        case GT_STORE_DYN_BLK:
         case GT_STORE_BLK:
             genCodeForStoreBlk(treeNode->AsBlk());
             break;
@@ -3057,7 +3056,7 @@ void CodeGen::genLclHeap(GenTree* tree)
 
 void CodeGen::genCodeForStoreBlk(GenTreeBlk* storeBlkNode)
 {
-    assert(storeBlkNode->OperIs(GT_STORE_DYN_BLK, GT_STORE_BLK));
+    assert(storeBlkNode->OperIs(GT_STORE_BLK));
 
     bool isCopyBlk = storeBlkNode->OperIsCopyBlkOp();
 

src/coreclr/jit/compiler.cpp

@@ -9920,7 +9920,6 @@ JITDBGAPI void __cdecl cTreeFlags(Compiler* comp, GenTree* tree)
 
             case GT_BLK:
             case GT_STORE_BLK:
-            case GT_STORE_DYN_BLK:
 
                 if (tree->gtFlags & GTF_IND_VOLATILE)
                 {

src/coreclr/jit/compiler.h

@@ -3364,9 +3364,6 @@ class Compiler
     GenTreeBlk* gtNewStoreBlkNode(
         ClassLayout* layout, GenTree* addr, GenTree* data, GenTreeFlags indirFlags = GTF_EMPTY);
 
-    GenTreeStoreDynBlk* gtNewStoreDynBlkNode(
-        GenTree* addr, GenTree* data, GenTree* dynamicSize, GenTreeFlags indirFlags = GTF_EMPTY);
-
     GenTreeStoreInd* gtNewStoreIndNode(
         var_types type, GenTree* addr, GenTree* data, GenTreeFlags indirFlags = GTF_EMPTY);
 
@@ -6463,7 +6460,6 @@ class Compiler
 public:
     GenTree* fgMorphInitBlock(GenTree* tree);
     GenTree* fgMorphCopyBlock(GenTree* tree);
-    GenTree* fgMorphStoreDynBlock(GenTreeStoreDynBlk* tree);
 private:
     GenTree* fgMorphSmpOp(GenTree* tree, MorphAddrContext* mac, bool* optAssertionPropDone = nullptr);
     void fgTryReplaceStructLocalWithField(GenTree* tree);
@@ -11447,28 +11443,6 @@ class GenTreeVisitor
                 break;
             }
 
-            case GT_STORE_DYN_BLK:
-            {
-                GenTreeStoreDynBlk* const dynBlock = node->AsStoreDynBlk();
-
-                result = WalkTree(&dynBlock->gtOp1, dynBlock);
-                if (result == fgWalkResult::WALK_ABORT)
-                {
-                    return result;
-                }
-                result = WalkTree(&dynBlock->gtOp2, dynBlock);
-                if (result == fgWalkResult::WALK_ABORT)
-                {
-                    return result;
-                }
-                result = WalkTree(&dynBlock->gtDynamicSize, dynBlock);
-                if (result == fgWalkResult::WALK_ABORT)
-                {
-                    return result;
-                }
-                break;
-            }
-
             case GT_CALL:
             {
                 GenTreeCall* const call = node->AsCall();

src/coreclr/jit/compiler.hpp

@@ -4362,21 +4362,6 @@ void GenTree::VisitOperands(TVisitor visitor)
             return;
         }
 
-        case GT_STORE_DYN_BLK:
-        {
-            GenTreeStoreDynBlk* const dynBlock = this->AsStoreDynBlk();
-            if (visitor(dynBlock->gtOp1) == VisitResult::Abort)
-            {
-                return;
-            }
-            if (visitor(dynBlock->gtOp2) == VisitResult::Abort)
-            {
-                return;
-            }
-            visitor(dynBlock->gtDynamicSize);
-            return;
-        }
-
         case GT_CALL:
         {
             GenTreeCall* const call = this->AsCall();