| /* |
| * Copyright (c) 2005-2006 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: Korey Sewell |
| * Kevin Lim |
| * Steve Reinhardt |
| */ |
| |
| #ifndef __CPU_O3_SCOREBOARD_HH__ |
| #define __CPU_O3_SCOREBOARD_HH__ |
| |
| #include <iostream> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/trace.hh" |
| #include "config/the_isa.hh" |
| #include "cpu/o3/comm.hh" |
| #include "debug/Scoreboard.hh" |
| |
| /** |
| * Implements a simple scoreboard to track which registers are |
| * ready. This class operates on the unified physical register space, |
| * so integer and floating-point registers are not distinguished. For |
| * convenience, it also accepts operations on the physical-space |
| * mapping of misc registers, which are numbered starting after the |
| * end of the actual physical register file. However, there is no |
| * actual scoreboard for misc registers, and they are always |
| * considered ready. |
| */ |
| class Scoreboard |
| { |
| private: |
| /** The object name, for DPRINTF. We have to declare this |
| * explicitly because Scoreboard is not a SimObject. */ |
| const std::string _name; |
| |
| /** Scoreboard of physical integer registers, saying whether or not they |
| * are ready. */ |
| std::vector<bool> regScoreBoard; |
| |
| /** The number of actual physical registers */ |
| unsigned numPhysRegs; |
| |
| /** |
| * The total number of registers which can be indexed, including |
| * the misc registers that come after the physical registers and |
| * which are hardwired to be always considered ready. |
| */ |
| unsigned M5_CLASS_VAR_USED numTotalRegs; |
| |
| /** The index of the zero register. */ |
| PhysRegIndex zeroRegIdx; |
| |
| /** The index of the FP zero register. */ |
| PhysRegIndex fpZeroRegIdx; |
| |
| bool isZeroReg(PhysRegIndex idx) const |
| { |
| return (idx == zeroRegIdx || |
| (THE_ISA == ALPHA_ISA && idx == fpZeroRegIdx)); |
| } |
| |
| public: |
| /** Constructs a scoreboard. |
| * @param _numPhysicalRegs Number of physical registers. |
| * @param _numMiscRegs Number of miscellaneous registers. |
| * @param _zeroRegIdx Index of the zero register. |
| * @param _fpZeroRegIdx Index of the FP zero register (if any, currently |
| * used only for Alpha). |
| */ |
| Scoreboard(const std::string &_my_name, |
| unsigned _numPhysicalRegs, |
| unsigned _numMiscRegs, |
| PhysRegIndex _zeroRegIdx, |
| PhysRegIndex _fpZeroRegIdx); |
| |
| /** Destructor. */ |
| ~Scoreboard() {} |
| |
| /** Returns the name of the scoreboard. */ |
| std::string name() const { return _name; }; |
| |
| /** Checks if the register is ready. */ |
| bool getReg(PhysRegIndex reg_idx) const |
| { |
| assert(reg_idx < numTotalRegs); |
| |
| if (reg_idx >= numPhysRegs) { |
| // misc regs are always ready |
| return true; |
| } |
| |
| bool ready = regScoreBoard[reg_idx]; |
| |
| if (isZeroReg(reg_idx)) |
| assert(ready); |
| |
| return ready; |
| } |
| |
| /** Sets the register as ready. */ |
| void setReg(PhysRegIndex reg_idx) |
| { |
| assert(reg_idx < numTotalRegs); |
| |
| if (reg_idx >= numPhysRegs) { |
| // misc regs are always ready, ignore attempts to change that |
| return; |
| } |
| |
| DPRINTF(Scoreboard, "Setting reg %i as ready\n", reg_idx); |
| |
| assert(reg_idx < numTotalRegs); |
| regScoreBoard[reg_idx] = true; |
| } |
| |
| /** Sets the register as not ready. */ |
| void unsetReg(PhysRegIndex reg_idx) |
| { |
| assert(reg_idx < numTotalRegs); |
| |
| if (reg_idx >= numPhysRegs) { |
| // misc regs are always ready, ignore attempts to change that |
| return; |
| } |
| |
| // zero reg should never be marked unready |
| if (isZeroReg(reg_idx)) |
| return; |
| |
| regScoreBoard[reg_idx] = false; |
| } |
| |
| }; |
| |
| #endif |