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// 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 SSA XX
XX XX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
*/
#pragma once
#include "jitstd.h"
struct SsaRenameStateForBlock
{
BasicBlock* m_bb;
unsigned m_count;
SsaRenameStateForBlock(BasicBlock* bb, unsigned count) : m_bb(bb), m_count(count)
{
}
SsaRenameStateForBlock() : m_bb(nullptr), m_count(0)
{
}
};
// A record indicating that local "m_loc" was defined in block "m_bb".
struct SsaRenameStateLocDef
{
BasicBlock* m_bb;
unsigned m_lclNum;
SsaRenameStateLocDef(BasicBlock* bb, unsigned lclNum) : m_bb(bb), m_lclNum(lclNum)
{
}
};
struct SsaRenameState
{
typedef jitstd::list<SsaRenameStateForBlock> Stack;
typedef Stack** Stacks;
typedef unsigned* Counts;
typedef jitstd::list<SsaRenameStateLocDef> DefStack;
SsaRenameState(const jitstd::allocator<int>& allocator, unsigned lvaCount);
void EnsureCounts();
void EnsureStacks();
// Requires "lclNum" to be a variable number for which a new count corresponding to a
// definition is desired. The method post increments the counter for the "lclNum."
unsigned CountForDef(unsigned lclNum);
// Requires "lclNum" to be a variable number for which an ssa number at the top of the
// stack is required i.e., for variable "uses."
unsigned CountForUse(unsigned lclNum);
// Requires "lclNum" to be a variable number, and requires "count" to represent
// an ssa number, that needs to be pushed on to the stack corresponding to the lclNum.
void Push(BasicBlock* bb, unsigned lclNum, unsigned count);
// Pop all stacks that have an entry for "bb" on top.
void PopBlockStacks(BasicBlock* bb);
// Similar functions for the special implicit "Heap" variable.
unsigned CountForHeapDef()
{
if (heapCount == 0)
{
heapCount = SsaConfig::FIRST_SSA_NUM;
}
unsigned res = heapCount;
heapCount++;
return res;
}
unsigned CountForHeapUse()
{
return heapStack.back().m_count;
}
void PushHeap(BasicBlock* bb, unsigned count)
{
heapStack.push_back(SsaRenameStateForBlock(bb, count));
}
void PopBlockHeapStack(BasicBlock* bb);
unsigned HeapCount()
{
return heapCount;
}
#ifdef DEBUG
// Debug interface
void DumpStacks();
#endif
private:
// Map of lclNum -> count.
Counts counts;
// Map of lclNum -> SsaRenameStateForBlock.
Stacks stacks;
// This list represents the set of locals defined in the current block.
DefStack definedLocs;
// Same state for the special implicit Heap variable.
Stack heapStack;
unsigned heapCount;
// Number of stacks/counts to allocate.
unsigned lvaCount;
// Allocator to allocate stacks.
jitstd::allocator<void> m_alloc;
};
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