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Diffstat (limited to 'src/cpu/o3/free_list.hh')
| -rw-r--r-- | src/cpu/o3/free_list.hh | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/cpu/o3/free_list.hh b/src/cpu/o3/free_list.hh new file mode 100644 index 000000000..29e84cd44 --- /dev/null +++ b/src/cpu/o3/free_list.hh @@ -0,0 +1,189 @@ +/* + * Copyright (c) 2004-2005 The Regents of The University of Michigan + * 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. + */ + +#ifndef __CPU_O3_FREE_LIST_HH__ +#define __CPU_O3_FREE_LIST_HH__ + +#include <iostream> +#include <queue> + +#include "arch/isa_traits.hh" +#include "base/trace.hh" +#include "base/traceflags.hh" +#include "cpu/o3/comm.hh" + +/** + * 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 SimpleFreeList +{ + private: + /** The list of free integer registers. */ + std::queue<PhysRegIndex> freeIntRegs; + + /** The list of free floating point registers. */ + std::queue<PhysRegIndex> freeFloatRegs; + + /** Number of logical integer registers. */ + int numLogicalIntRegs; + + /** Number of physical integer registers. */ + int numPhysicalIntRegs; + + /** Number of logical floating point registers. */ + int numLogicalFloatRegs; + + /** Number of physical floating point registers. */ + int numPhysicalFloatRegs; + + /** Total number of physical registers. */ + int numPhysicalRegs; + + public: + /** Constructs a free list. + * @param activeThreads Number of active threads. + * @param _numLogicalIntRegs Number of logical integer registers. + * @param _numPhysicalIntRegs Number of physical integer registers. + * @param _numLogicalFloatRegs Number of logical fp registers. + * @param _numPhysicalFloatRegs Number of physical fp registers. + */ + SimpleFreeList(unsigned activeThreads, + unsigned _numLogicalIntRegs, + unsigned _numPhysicalIntRegs, + unsigned _numLogicalFloatRegs, + unsigned _numPhysicalFloatRegs); + + /** Gives the name of the freelist. */ + std::string name() const; + + /** Gets a free integer register. */ + inline PhysRegIndex getIntReg(); + + /** Gets a free fp register. */ + inline PhysRegIndex getFloatReg(); + + /** Adds a register back to the free list. */ + inline void addReg(PhysRegIndex freed_reg); + + /** Adds an integer register back to the free list. */ + inline void addIntReg(PhysRegIndex freed_reg); + + /** Adds a fp register back to the free list. */ + inline void addFloatReg(PhysRegIndex freed_reg); + + /** Checks if there are any free integer registers. */ + bool hasFreeIntRegs() + { return !freeIntRegs.empty(); } + + /** Checks if there are any free fp registers. */ + bool hasFreeFloatRegs() + { return !freeFloatRegs.empty(); } + + /** Returns the number of free integer registers. */ + int numFreeIntRegs() + { return freeIntRegs.size(); } + + /** Returns the number of free fp registers. */ + int numFreeFloatRegs() + { return freeFloatRegs.size(); } +}; + +inline PhysRegIndex +SimpleFreeList::getIntReg() +{ + DPRINTF(FreeList, "Trying to get free integer register.\n"); + + if (freeIntRegs.empty()) { + panic("No free integer registers!"); + } + + PhysRegIndex free_reg = freeIntRegs.front(); + + freeIntRegs.pop(); + + return(free_reg); +} + +inline PhysRegIndex +SimpleFreeList::getFloatReg() +{ + DPRINTF(FreeList, "Trying to get free float register.\n"); + + if (freeFloatRegs.empty()) { + panic("No free integer registers!"); + } + + PhysRegIndex free_reg = freeFloatRegs.front(); + + freeFloatRegs.pop(); + + return(free_reg); +} + +inline void +SimpleFreeList::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 (freed_reg < numPhysicalIntRegs) { + if (freed_reg != TheISA::ZeroReg) + freeIntRegs.push(freed_reg); + } else if (freed_reg < numPhysicalRegs) { + if (freed_reg != (TheISA::ZeroReg + numPhysicalIntRegs)) + freeFloatRegs.push(freed_reg); + } +} + +inline void +SimpleFreeList::addIntReg(PhysRegIndex freed_reg) +{ + DPRINTF(FreeList,"Freeing int register %i.\n", freed_reg); + + freeIntRegs.push(freed_reg); +} + +inline void +SimpleFreeList::addFloatReg(PhysRegIndex freed_reg) +{ + DPRINTF(FreeList,"Freeing float register %i.\n", freed_reg); + + freeFloatRegs.push(freed_reg); +} + +#endif // __CPU_O3_FREE_LIST_HH__ |