1/* 2 * Copyright (c) 2005-2006 The Regents of The University of Michigan
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3 * Copyright (c) 2013 Advanced Micro Devices, Inc. |
4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are 8 * met: redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer; 10 * redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution; 13 * neither the name of the copyright holders nor the names of its 14 * contributors may be used to endorse or promote products derived from 15 * this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * Authors: Korey Sewell 30 * Kevin Lim
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31 * Steve Reinhardt |
32 */ 33 34#ifndef __CPU_O3_SCOREBOARD_HH__ 35#define __CPU_O3_SCOREBOARD_HH__ 36 37#include <iostream> 38#include <utility> 39#include <vector> 40 41#include "base/trace.hh"
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42#include "config/the_isa.hh" |
43#include "cpu/o3/comm.hh"
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44#include "debug/Scoreboard.hh" |
45 46/**
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43 * Implements a simple scoreboard to track which registers are ready.
44 * This class assumes that the fp registers start, index wise, right after
45 * the integer registers. The misc. registers start, index wise, right after
46 * the fp registers.
47 * @todo: Fix up handling of the zero register in case the decoder does not
48 * automatically make insts that write the zero register into nops.
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47 * Implements a simple scoreboard to track which registers are 48 * ready. This class operates on the unified physical register space, 49 * so integer and floating-point registers are not distinguished. For 50 * convenience, it also accepts operations on the physical-space 51 * mapping of misc registers, which are numbered starting after the 52 * end of the actual physical register file. However, there is no 53 * actual scoreboard for misc registers, and they are always 54 * considered ready. |
55 */ 56class Scoreboard 57{
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58 private: 59 /** The object name, for DPRINTF. We have to declare this 60 * explicitly because Scoreboard is not a SimObject. */ 61 const std::string _name; 62 63 /** Scoreboard of physical integer registers, saying whether or not they 64 * are ready. */ 65 std::vector<bool> regScoreBoard; 66 67 /** The number of actual physical registers */ 68 unsigned numPhysRegs; 69 70 /** 71 * The total number of registers which can be indexed, including 72 * the misc registers that come after the physical registers and 73 * which are hardwired to be always considered ready. 74 */ 75 unsigned numTotalRegs; 76 77 /** The index of the zero register. */ 78 PhysRegIndex zeroRegIdx; 79 80 /** The index of the FP zero register. */ 81 PhysRegIndex fpZeroRegIdx; 82 83 bool isZeroReg(PhysRegIndex idx) const 84 { 85 return (idx == zeroRegIdx || 86 (THE_ISA == ALPHA_ISA && idx == fpZeroRegIdx)); 87 } 88 |
89 public: 90 /** Constructs a scoreboard.
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54 * @param activeThreads The number of active threads.
55 * @param _numLogicalIntRegs Number of logical integer registers.
56 * @param _numPhysicalIntRegs Number of physical integer registers.
57 * @param _numLogicalFloatRegs Number of logical fp registers.
58 * @param _numPhysicalFloatRegs Number of physical fp registers.
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91 * @param _numPhysicalRegs Number of physical registers. |
92 * @param _numMiscRegs Number of miscellaneous registers. 93 * @param _zeroRegIdx Index of the zero register.
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94 * @param _fpZeroRegIdx Index of the FP zero register (if any, currently 95 * used only for Alpha). |
96 */
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62 Scoreboard(unsigned activeThreads,
63 unsigned _numLogicalIntRegs,
64 unsigned _numPhysicalIntRegs,
65 unsigned _numLogicalFloatRegs,
66 unsigned _numPhysicalFloatRegs,
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97 Scoreboard(const std::string &_my_name, 98 unsigned _numPhysicalRegs, |
99 unsigned _numMiscRegs,
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68 unsigned _zeroRegIdx);
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100 PhysRegIndex _zeroRegIdx, 101 PhysRegIndex _fpZeroRegIdx); |
102 103 /** Destructor. */ 104 ~Scoreboard() {} 105 106 /** Returns the name of the scoreboard. */
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74 std::string name() const;
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107 std::string name() const { return _name; }; |
108 109 /** Checks if the register is ready. */
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77 bool getReg(PhysRegIndex ready_reg);
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110 bool getReg(PhysRegIndex reg_idx) const 111 { 112 assert(reg_idx < numTotalRegs); |
113
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79 /** Sets the register as ready. */
80 void setReg(PhysRegIndex phys_reg);
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114 if (reg_idx >= numPhysRegs) { 115 // misc regs are always ready 116 return true; 117 } |
118
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82 /** Sets the register as not ready. */
83 void unsetReg(PhysRegIndex ready_reg);
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119 bool ready = regScoreBoard[reg_idx]; |
120
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85 private:
86 /** Scoreboard of physical integer registers, saying whether or not they
87 * are ready.
88 */
89 std::vector<bool> regScoreBoard;
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121 if (isZeroReg(reg_idx)) 122 assert(ready); |
123
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91 /** Number of logical integer registers. */
92 int numLogicalIntRegs;
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124 return ready; 125 } |
126
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94 /** Number of physical integer registers. */
95 int numPhysicalIntRegs;
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127 /** Sets the register as ready. */ 128 void setReg(PhysRegIndex reg_idx) 129 { 130 assert(reg_idx < numTotalRegs); |
131
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97 /** Number of logical floating point registers. */
98 int numLogicalFloatRegs;
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132 if (reg_idx >= numPhysRegs) { 133 // misc regs are always ready, ignore attempts to change that 134 return; 135 } |
136
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100 /** Number of physical floating point registers. */
101 int numPhysicalFloatRegs;
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137 DPRINTF(Scoreboard, "Setting reg %i as ready\n", reg_idx); |
138
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103 /** Number of miscellaneous registers. */
104 int numMiscRegs;
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139 assert(reg_idx < numTotalRegs); 140 regScoreBoard[reg_idx] = true; 141 } |
142
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106 /** Number of logical integer + float registers. */
107 int numLogicalRegs;
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143 /** Sets the register as not ready. */ 144 void unsetReg(PhysRegIndex reg_idx) 145 { 146 assert(reg_idx < numTotalRegs); |
147
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109 /** Number of physical integer + float registers. */
110 int numPhysicalRegs;
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148 if (reg_idx >= numPhysRegs) { 149 // misc regs are always ready, ignore attempts to change that 150 return; 151 } |
152
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112 /** The logical index of the zero register. */
113 int zeroRegIdx;
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153 // zero reg should never be marked unready 154 if (isZeroReg(reg_idx)) 155 return; |
156
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115 int currentSize;
116
117 void
118 resize(int newSize)
119 {
120 currentSize = newSize;
121 regScoreBoard.resize(newSize);
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157 regScoreBoard[reg_idx] = false; |
158 } 159
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124 bool
125 indexInBounds(int idx)
126 {
127 return idx < currentSize;
128 }
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160}; 161 162#endif
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