/*
* 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
#include "cpu/o3/scoreboard.hh"
#include "debug/Scoreboard.hh"
-Scoreboard::Scoreboard(unsigned activeThreads,
- unsigned _numLogicalIntRegs,
- unsigned _numPhysicalIntRegs,
- unsigned _numLogicalFloatRegs,
- unsigned _numPhysicalFloatRegs,
- unsigned _numMiscRegs,
- unsigned _zeroRegIdx)
- : numLogicalIntRegs(_numLogicalIntRegs),
- numPhysicalIntRegs(_numPhysicalIntRegs),
- numLogicalFloatRegs(_numLogicalFloatRegs),
- numPhysicalFloatRegs(_numPhysicalFloatRegs),
- numMiscRegs(_numMiscRegs),
- zeroRegIdx(_zeroRegIdx)
+Scoreboard::Scoreboard(const std::string &_my_name,
+ unsigned _numPhysicalRegs, unsigned _numMiscRegs,
+ PhysRegIndex _zeroRegIdx, PhysRegIndex _fpZeroRegIdx)
+ : _name(_my_name),
+ regScoreBoard(_numPhysicalRegs, true),
+ numPhysRegs(_numPhysicalRegs),
+ numTotalRegs(_numPhysicalRegs + _numMiscRegs),
+ zeroRegIdx(_zeroRegIdx), fpZeroRegIdx(_fpZeroRegIdx)
{
- //Get Register Sizes
- numLogicalRegs = numLogicalIntRegs + numLogicalFloatRegs;
- numPhysicalRegs = numPhysicalIntRegs + numPhysicalFloatRegs;
-
- //Resize scoreboard appropriately
- resize(numPhysicalRegs + (numMiscRegs * activeThreads));
-
- //Initialize values
- for (int i=0; i < numLogicalIntRegs * activeThreads; i++) {
- assert(indexInBounds(i));
- regScoreBoard[i] = 1;
- }
-
- for (int i= numPhysicalIntRegs;
- i < numPhysicalIntRegs + (numLogicalFloatRegs * activeThreads);
- i++) {
- assert(indexInBounds(i));
- regScoreBoard[i] = 1;
- }
-
- for (int i = numPhysicalRegs;
- i < numPhysicalRegs + (numMiscRegs * activeThreads);
- i++) {
- assert(indexInBounds(i));
- regScoreBoard[i] = 1;
- }
-}
-
-std::string
-Scoreboard::name() const
-{
- return "cpu.scoreboard";
-}
-
-bool
-Scoreboard::getReg(PhysRegIndex phys_reg)
-{
-#if THE_ISA == ALPHA_ISA
- // Always ready if int or fp zero reg.
- if (phys_reg == zeroRegIdx ||
- phys_reg == (zeroRegIdx + numPhysicalIntRegs)) {
- return 1;
- }
-#else
- // Always ready if int zero reg.
- if (phys_reg == zeroRegIdx) {
- return 1;
- }
-#endif
-
- assert(indexInBounds(phys_reg));
- return regScoreBoard[phys_reg];
-}
-
-void
-Scoreboard::setReg(PhysRegIndex phys_reg)
-{
- DPRINTF(Scoreboard, "Setting reg %i as ready\n", phys_reg);
-
- assert(indexInBounds(phys_reg));
- regScoreBoard[phys_reg] = 1;
-}
-
-void
-Scoreboard::unsetReg(PhysRegIndex ready_reg)
-{
-#if THE_ISA == ALPHA_ISA
- if (ready_reg == zeroRegIdx ||
- ready_reg == (zeroRegIdx + numPhysicalIntRegs)) {
- // Don't do anything if int or fp zero reg.
- return;
- }
-#else
- if (ready_reg == zeroRegIdx) {
- // Don't do anything if int zero reg.
- return;
- }
-#endif
-
- assert(indexInBounds(ready_reg));
- regScoreBoard[ready_reg] = 0;
}
/*
* 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
*
* Authors: Korey Sewell
* Kevin Lim
+ * Steve Reinhardt
*/
#ifndef __CPU_O3_SCOREBOARD_HH__
#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 assumes that the fp registers start, index wise, right after
- * the integer registers. The misc. registers start, index wise, right after
- * the fp registers.
- * @todo: Fix up handling of the zero register in case the decoder does not
- * automatically make insts that write the zero register into nops.
+ * 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 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 activeThreads The 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.
+ * @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(unsigned activeThreads,
- unsigned _numLogicalIntRegs,
- unsigned _numPhysicalIntRegs,
- unsigned _numLogicalFloatRegs,
- unsigned _numPhysicalFloatRegs,
+ Scoreboard(const std::string &_my_name,
+ unsigned _numPhysicalRegs,
unsigned _numMiscRegs,
- unsigned _zeroRegIdx);
+ PhysRegIndex _zeroRegIdx,
+ PhysRegIndex _fpZeroRegIdx);
/** Destructor. */
~Scoreboard() {}
/** Returns the name of the scoreboard. */
- std::string name() const;
+ std::string name() const { return _name; };
/** Checks if the register is ready. */
- bool getReg(PhysRegIndex ready_reg);
-
- /** Sets the register as ready. */
- void setReg(PhysRegIndex phys_reg);
+ bool getReg(PhysRegIndex reg_idx) const
+ {
+ assert(reg_idx < numTotalRegs);
- /** Sets the register as not ready. */
- void unsetReg(PhysRegIndex ready_reg);
+ if (reg_idx >= numPhysRegs) {
+ // misc regs are always ready
+ return true;
+ }
- private:
- /** Scoreboard of physical integer registers, saying whether or not they
- * are ready.
- */
- std::vector<bool> regScoreBoard;
+ bool ready = regScoreBoard[reg_idx];
- /** Number of logical integer registers. */
- int numLogicalIntRegs;
+ if (isZeroReg(reg_idx))
+ assert(ready);
- /** Number of physical integer registers. */
- int numPhysicalIntRegs;
+ return ready;
+ }
- /** Number of logical floating point registers. */
- int numLogicalFloatRegs;
+ /** Sets the register as ready. */
+ void setReg(PhysRegIndex reg_idx)
+ {
+ assert(reg_idx < numTotalRegs);
- /** Number of physical floating point registers. */
- int numPhysicalFloatRegs;
+ if (reg_idx >= numPhysRegs) {
+ // misc regs are always ready, ignore attempts to change that
+ return;
+ }
- /** Number of miscellaneous registers. */
- int numMiscRegs;
+ DPRINTF(Scoreboard, "Setting reg %i as ready\n", reg_idx);
- /** Number of logical integer + float registers. */
- int numLogicalRegs;
+ assert(reg_idx < numTotalRegs);
+ regScoreBoard[reg_idx] = true;
+ }
- /** Number of physical integer + float registers. */
- int numPhysicalRegs;
+ /** Sets the register as not ready. */
+ void unsetReg(PhysRegIndex reg_idx)
+ {
+ assert(reg_idx < numTotalRegs);
- /** The logical index of the zero register. */
- int zeroRegIdx;
+ if (reg_idx >= numPhysRegs) {
+ // misc regs are always ready, ignore attempts to change that
+ return;
+ }
- int currentSize;
+ // zero reg should never be marked unready
+ if (isZeroReg(reg_idx))
+ return;
- void
- resize(int newSize)
- {
- currentSize = newSize;
- regScoreBoard.resize(newSize);
+ regScoreBoard[reg_idx] = false;
}
- bool
- indexInBounds(int idx)
- {
- return idx < currentSize;
- }
};
#endif
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