| /* |
| * Copyright (c) 2004-2005 The Regents of The University of Michigan |
| * Copyright (c) 2013 Advanced Micro Devices, Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer; |
| * redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution; |
| * neither the name of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| * Authors: Kevin Lim |
| */ |
| |
| #ifndef __CPU_O3_FREE_LIST_HH__ |
| #define __CPU_O3_FREE_LIST_HH__ |
| |
| #include <iostream> |
| #include <queue> |
| |
| #include "base/misc.hh" |
| #include "base/trace.hh" |
| #include "cpu/o3/comm.hh" |
| #include "cpu/o3/regfile.hh" |
| #include "debug/FreeList.hh" |
| |
| /** |
| * Free list for a single class of registers (e.g., integer |
| * or floating point). Because the register class is implicitly |
| * determined by the rename map instance being accessed, all |
| * architectural register index parameters and values in this class |
| * are relative (e.g., %fp2 is just index 2). |
| */ |
| class SimpleFreeList |
| { |
| private: |
| |
| /** The actual free list */ |
| std::queue<PhysRegIndex> freeRegs; |
| |
| public: |
| |
| SimpleFreeList() {}; |
| |
| /** Add a physical register to the free list */ |
| void addReg(PhysRegIndex reg) { freeRegs.push(reg); } |
| |
| /** Get the next available register from the free list */ |
| PhysRegIndex getReg() |
| { |
| assert(!freeRegs.empty()); |
| PhysRegIndex free_reg = freeRegs.front(); |
| freeRegs.pop(); |
| return free_reg; |
| } |
| |
| /** Return the number of free registers on the list. */ |
| unsigned numFreeRegs() const { return freeRegs.size(); } |
| |
| /** True iff there are free registers on the list. */ |
| bool hasFreeRegs() const { return !freeRegs.empty(); } |
| }; |
| |
| |
| /** |
| * FreeList class that simply holds the list of free integer and floating |
| * point registers. Can request for a free register of either type, and |
| * also send back free registers of either type. This is a very simple |
| * class, but it should be sufficient for most implementations. Like all |
| * other classes, it assumes that the indices for the floating point |
| * registers starts after the integer registers end. Hence the variable |
| * numPhysicalIntRegs is logically equivalent to the baseFP dependency. |
| * Note that while this most likely should be called FreeList, the name |
| * "FreeList" is used in a typedef within the CPU Policy, and therefore no |
| * class can be named simply "FreeList". |
| * @todo: Give a better name to the base FP dependency. |
| */ |
| class UnifiedFreeList |
| { |
| private: |
| |
| /** The object name, for DPRINTF. We have to declare this |
| * explicitly because Scoreboard is not a SimObject. */ |
| const std::string _name; |
| |
| /** The list of free integer registers. */ |
| SimpleFreeList intList; |
| |
| /** The list of free floating point registers. */ |
| SimpleFreeList floatList; |
| |
| /** The list of free condition-code registers. */ |
| SimpleFreeList ccList; |
| |
| /** |
| * The register file object is used only to distinguish integer |
| * from floating-point physical register indices. |
| */ |
| PhysRegFile *regFile; |
| |
| /* |
| * We give UnifiedRenameMap internal access so it can get at the |
| * internal per-class free lists and associate those with its |
| * per-class rename maps. See UnifiedRenameMap::init(). |
| */ |
| friend class UnifiedRenameMap; |
| |
| public: |
| /** Constructs a free list. |
| * @param _numPhysicalIntRegs Number of physical integer registers. |
| * @param reservedIntRegs Number of integer registers already |
| * used by initial mappings. |
| * @param _numPhysicalFloatRegs Number of physical fp registers. |
| * @param reservedFloatRegs Number of fp registers already |
| * used by initial mappings. |
| */ |
| UnifiedFreeList(const std::string &_my_name, PhysRegFile *_regFile); |
| |
| /** Gives the name of the freelist. */ |
| std::string name() const { return _name; }; |
| |
| /** Returns a pointer to the condition-code free list */ |
| SimpleFreeList *getCCList() { return &ccList; } |
| |
| /** Gets a free integer register. */ |
| PhysRegIndex getIntReg() { return intList.getReg(); } |
| |
| /** Gets a free fp register. */ |
| PhysRegIndex getFloatReg() { return floatList.getReg(); } |
| |
| /** Gets a free cc register. */ |
| PhysRegIndex getCCReg() { return ccList.getReg(); } |
| |
| /** Adds a register back to the free list. */ |
| void addReg(PhysRegIndex freed_reg); |
| |
| /** Adds an integer register back to the free list. */ |
| void addIntReg(PhysRegIndex freed_reg) { intList.addReg(freed_reg); } |
| |
| /** Adds a fp register back to the free list. */ |
| void addFloatReg(PhysRegIndex freed_reg) { floatList.addReg(freed_reg); } |
| |
| /** Adds a cc register back to the free list. */ |
| void addCCReg(PhysRegIndex freed_reg) { ccList.addReg(freed_reg); } |
| |
| /** Checks if there are any free integer registers. */ |
| bool hasFreeIntRegs() const { return intList.hasFreeRegs(); } |
| |
| /** Checks if there are any free fp registers. */ |
| bool hasFreeFloatRegs() const { return floatList.hasFreeRegs(); } |
| |
| /** Checks if there are any free cc registers. */ |
| bool hasFreeCCRegs() const { return ccList.hasFreeRegs(); } |
| |
| /** Returns the number of free integer registers. */ |
| unsigned numFreeIntRegs() const { return intList.numFreeRegs(); } |
| |
| /** Returns the number of free fp registers. */ |
| unsigned numFreeFloatRegs() const { return floatList.numFreeRegs(); } |
| |
| /** Returns the number of free cc registers. */ |
| unsigned numFreeCCRegs() const { return ccList.numFreeRegs(); } |
| }; |
| |
| inline void |
| UnifiedFreeList::addReg(PhysRegIndex freed_reg) |
| { |
| DPRINTF(FreeList,"Freeing register %i.\n", freed_reg); |
| //Might want to add in a check for whether or not this register is |
| //already in there. A bit vector or something similar would be useful. |
| if (regFile->isIntPhysReg(freed_reg)) { |
| intList.addReg(freed_reg); |
| } else if (regFile->isFloatPhysReg(freed_reg)) { |
| floatList.addReg(freed_reg); |
| } else { |
| assert(regFile->isCCPhysReg(freed_reg)); |
| ccList.addReg(freed_reg); |
| } |
| |
| // These assert conditions ensure that the number of free |
| // registers are not more than the # of total Physical Registers. |
| // If this were false, it would mean that registers |
| // have been freed twice, overflowing the free register |
| // pool and potentially crashing SMT workloads. |
| // ---- |
| // Comment out for now so as to not potentially break |
| // CMP and single-threaded workloads |
| // ---- |
| // assert(freeIntRegs.size() <= numPhysicalIntRegs); |
| // assert(freeFloatRegs.size() <= numPhysicalFloatRegs); |
| } |
| |
| |
| #endif // __CPU_O3_FREE_LIST_HH__ |