1/*
2 * Copyright (c) 2005-2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Korey Sewell
29 * Kevin Lim
30 */
31
32#ifndef __CPU_O3_SCOREBOARD_HH__
33#define __CPU_O3_SCOREBOARD_HH__
34
35#include <iostream>
36#include <utility>
37#include <vector>
38
39#include "base/trace.hh"
40#include "base/traceflags.hh"
41#include "cpu/o3/comm.hh"
42
43/**
44 * Implements a simple scoreboard to track which registers are ready.
45 * This class assumes that the fp registers start, index wise, right after
46 * the integer registers. The misc. registers start, index wise, right after
47 * the fp registers.
48 * @todo: Fix up handling of the zero register in case the decoder does not
49 * automatically make insts that write the zero register into nops.
50 */
51class Scoreboard
52{
53 public:
54 /** Constructs a scoreboard.
55 * @param activeThreads The number of active threads.
56 * @param _numLogicalIntRegs Number of logical integer registers.
57 * @param _numPhysicalIntRegs Number of physical integer registers.
58 * @param _numLogicalFloatRegs Number of logical fp registers.
59 * @param _numPhysicalFloatRegs Number of physical fp registers.
60 * @param _numMiscRegs Number of miscellaneous registers.
61 * @param _zeroRegIdx Index of the zero register.
62 */
63 Scoreboard(unsigned activeThreads,
64 unsigned _numLogicalIntRegs,
65 unsigned _numPhysicalIntRegs,
66 unsigned _numLogicalFloatRegs,
67 unsigned _numPhysicalFloatRegs,
68 unsigned _numMiscRegs,
69 unsigned _zeroRegIdx);
70
71 /** Destructor. */
72 ~Scoreboard() {}
73
74 /** Returns the name of the scoreboard. */
75 std::string name() const;
76
77 /** Checks if the register is ready. */
78 bool getReg(PhysRegIndex ready_reg);
79
80 /** Sets the register as ready. */
81 void setReg(PhysRegIndex phys_reg);
82
83 /** Sets the register as not ready. */
84 void unsetReg(PhysRegIndex ready_reg);
85
86 private:
87 /** Scoreboard of physical integer registers, saying whether or not they
88 * are ready.
89 */
90 std::vector<bool> regScoreBoard;
91
92 /** Number of logical integer registers. */
93 int numLogicalIntRegs;
94
95 /** Number of physical integer registers. */
96 int numPhysicalIntRegs;
97
98 /** Number of logical floating point registers. */
99 int numLogicalFloatRegs;
100
101 /** Number of physical floating point registers. */
102 int numPhysicalFloatRegs;
103
104 /** Number of miscellaneous registers. */
105 int numMiscRegs;
106
107 /** Number of logical integer + float registers. */
108 int numLogicalRegs;
109
110 /** Number of physical integer + float registers. */
111 int numPhysicalRegs;
112
113 /** The logical index of the zero register. */
114 int zeroRegIdx;
115
116 int currentSize;
117
118 void
119 resize(int newSize)
120 {
121 currentSize = newSize;
122 regScoreBoard.resize(newSize);
123 }
124
125 bool
126 indexInBounds(int idx)
127 {
128 return idx < currentSize;
129 }
130};
131
132#endif