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Diffstat (limited to 'src/jit/objectalloc.cpp')
| -rw-r--r-- | src/jit/objectalloc.cpp | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/src/jit/objectalloc.cpp b/src/jit/objectalloc.cpp new file mode 100644 index 0000000000..2e19f4378d --- /dev/null +++ b/src/jit/objectalloc.cpp @@ -0,0 +1,207 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. + +/*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX +XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX +XX XX +XX ObjectAllocator XX +XX XX +XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX +XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX +*/ + +#include "jitpch.h" +#ifdef _MSC_VER +#pragma hdrstop +#endif + +//=============================================================================== + +//------------------------------------------------------------------------ +// DoPhase: Run analysis (if object stack allocation is enabled) and then +// morph each GT_ALLOCOBJ node either into an allocation helper +// call or stack allocation. +// Notes: +// Runs only if Compiler::optMethodFlags has flag OMF_HAS_NEWOBJ set. +void ObjectAllocator::DoPhase() +{ + if ((comp->optMethodFlags & OMF_HAS_NEWOBJ) == 0) + { + return; + } + + if (IsObjectStackAllocationEnabled()) + { + DoAnalysis(); + } + + MorphAllocObjNodes(); +} + +//------------------------------------------------------------------------ +// DoAnalysis: Walk over basic blocks of the method and detect all local +// variables that can be allocated on the stack. +// +// Assumptions: +// Must be run after the dominators have been computed (we need this +// information to detect loops). +void ObjectAllocator::DoAnalysis() +{ + assert(m_IsObjectStackAllocationEnabled); + assert(comp->fgDomsComputed); + // TODO-ObjectStackAllocation + NYI("DoAnalysis"); +} + +//------------------------------------------------------------------------ +// MorphAllocObjNodes: Morph each GT_ALLOCOBJ node either into an +// allocation helper call or stack allocation. +// +// Notes: +// Runs only over the blocks having bbFlags BBF_HAS_NEWOBJ set. +void ObjectAllocator::MorphAllocObjNodes() +{ + BasicBlock* block; + + foreach_block(comp, block) + { + const bool basicBlockHasNewObj = (block->bbFlags & BBF_HAS_NEWOBJ) == BBF_HAS_NEWOBJ; +#ifndef DEBUG + if (!basicBlockHasNewObj) + { + continue; + } +#endif // DEBUG + + for (GenTreeStmt* stmt = block->firstStmt(); stmt; stmt = stmt->gtNextStmt) + { + GenTreePtr stmtExpr = stmt->gtStmtExpr; + GenTreePtr op2 = nullptr; + + bool canonicalAllocObjFound = false; + + if (stmtExpr->OperGet() == GT_ASG && stmtExpr->TypeGet() == TYP_REF) + { + op2 = stmtExpr->gtGetOp2(); + + if (op2->OperGet() == GT_ALLOCOBJ) + { + canonicalAllocObjFound = true; + } + } + + if (canonicalAllocObjFound) + { + assert(basicBlockHasNewObj); + //------------------------------------------------------------------------ + // We expect the following expression tree at this point + // * GT_STMT void (top level) + // | /--* GT_ALLOCOBJ ref + // \--* GT_ASG ref + // \--* GT_LCL_VAR ref + //------------------------------------------------------------------------ + + GenTreePtr op1 = stmtExpr->gtGetOp1(); + + assert(op1->OperGet() == GT_LCL_VAR); + assert(op1->TypeGet() == TYP_REF); + assert(op2 != nullptr); + assert(op2->OperGet() == GT_ALLOCOBJ); + + GenTreeAllocObj* asAllocObj = op2->AsAllocObj(); + unsigned int lclNum = op1->AsLclVar()->GetLclNum(); + + if (IsObjectStackAllocationEnabled() && CanAllocateLclVarOnStack(lclNum)) + { + op2 = MorphAllocObjNodeIntoStackAlloc(asAllocObj, block, stmt); + } + else + { + op2 = MorphAllocObjNodeIntoHelperCall(asAllocObj); + } + + // Propagate flags of op2 to its parent. + stmtExpr->gtOp.gtOp2 = op2; + stmtExpr->gtFlags |= op2->gtFlags & GTF_ALL_EFFECT; + } +#ifdef DEBUG + else + { + // We assume that GT_ALLOCOBJ nodes are always present in the + // canonical form. + comp->fgWalkTreePre(&stmt->gtStmtExpr, AssertWhenAllocObjFoundVisitor); + } +#endif // DEBUG + } + } +} + +//------------------------------------------------------------------------ +// MorphAllocObjNodeIntoHelperCall: Morph a GT_ALLOCOBJ node into an +// allocation helper call. +// +// Arguments: +// allocObj - GT_ALLOCOBJ that will be replaced by helper call. +// +// Return Value: +// Address of helper call node (can be the same as allocObj). +// +// Notes: +// Must update parents flags after this. +GenTreePtr ObjectAllocator::MorphAllocObjNodeIntoHelperCall(GenTreeAllocObj* allocObj) +{ + assert(allocObj != nullptr); + + GenTreePtr op1 = allocObj->gtGetOp1(); + + GenTreePtr helperCall = comp->fgMorphIntoHelperCall(allocObj, allocObj->gtNewHelper, comp->gtNewArgList(op1)); + + return helperCall; +} + +//------------------------------------------------------------------------ +// MorphAllocObjNodeIntoStackAlloc: Morph a GT_ALLOCOBJ node into stack +// allocation. +// Arguments: +// allocObj - GT_ALLOCOBJ that will be replaced by helper call. +// block - a basic block where allocObj is +// stmt - a statement where allocObj is +// +// Return Value: +// Address of tree doing stack allocation (can be the same as allocObj). +// +// Notes: +// Must update parents flags after this. +// This function can insert additional statements before stmt. +GenTreePtr ObjectAllocator::MorphAllocObjNodeIntoStackAlloc(GenTreeAllocObj* allocObj, + BasicBlock* block, + GenTreeStmt* stmt) +{ + assert(allocObj != nullptr); + assert(m_AnalysisDone); + + // TODO-StackAllocation + NYI("MorphAllocObjIntoStackAlloc"); + + return allocObj; +} + +#ifdef DEBUG + +//------------------------------------------------------------------------ +// AssertWhenAllocObjFoundVisitor: Look for a GT_ALLOCOBJ node and assert +// when found one. +Compiler::fgWalkResult ObjectAllocator::AssertWhenAllocObjFoundVisitor(GenTreePtr* pTree, Compiler::fgWalkData* data) +{ + GenTreePtr tree = *pTree; + + assert(tree != nullptr); + assert(tree->OperGet() != GT_ALLOCOBJ); + + return Compiler::fgWalkResult::WALK_CONTINUE; +} + +#endif // DEBUG + +//=============================================================================== |