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Diffstat (limited to 'cpu/beta_cpu/rename_map.cc')
| -rw-r--r-- | cpu/beta_cpu/rename_map.cc | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/cpu/beta_cpu/rename_map.cc b/cpu/beta_cpu/rename_map.cc new file mode 100644 index 000000000..45b8084de --- /dev/null +++ b/cpu/beta_cpu/rename_map.cc @@ -0,0 +1,319 @@ + +#include <vector> + +#include "cpu/beta_cpu/rename_map.hh" + +using namespace std; + +// Todo: Consider making functions inline. Avoid having things that are +// using the zero register or misc registers from adding on the registers +// to the free list. Possibly remove the direct communication between +// this and the freelist. Considering making inline bool functions that +// determine if the register is a logical int, logical fp, physical int, +// physical fp, etc. + +SimpleRenameMap::SimpleRenameMap(unsigned _numLogicalIntRegs, + unsigned _numPhysicalIntRegs, + unsigned _numLogicalFloatRegs, + unsigned _numPhysicalFloatRegs, + unsigned _numMiscRegs, + RegIndex _intZeroReg, + RegIndex _floatZeroReg) + : numLogicalIntRegs(_numLogicalIntRegs), + numPhysicalIntRegs(_numPhysicalIntRegs), + numLogicalFloatRegs(_numLogicalFloatRegs), + numPhysicalFloatRegs(_numPhysicalFloatRegs), + numMiscRegs(_numMiscRegs), + intZeroReg(_intZeroReg), + floatZeroReg(_floatZeroReg) +{ + DPRINTF(Rename, "Rename: Creating rename map. Phys: %i / %i, Float: " + "%i / %i.\n", numLogicalIntRegs, numPhysicalIntRegs, + numLogicalFloatRegs, numPhysicalFloatRegs); + + numLogicalRegs = numLogicalIntRegs + numLogicalFloatRegs; + + numPhysicalRegs = numPhysicalIntRegs + numPhysicalFloatRegs; + + //Create the rename maps, and their scoreboards. + intRenameMap = new RenameEntry[numLogicalIntRegs]; + floatRenameMap = new RenameEntry[numLogicalRegs]; + + // Should combine this into one scoreboard. + intScoreboard.resize(numPhysicalIntRegs); + floatScoreboard.resize(numPhysicalRegs); + miscScoreboard.resize(numPhysicalRegs + numMiscRegs); + + // Initialize the entries in the integer rename map to point to the + // physical registers of the same index, and consider each register + // ready until the first rename occurs. + for (RegIndex index = 0; index < numLogicalIntRegs; ++index) + { + intRenameMap[index].physical_reg = index; + intScoreboard[index] = 1; + } + + // Initialize the rest of the physical registers (the ones that don't + // directly map to a logical register) as unready. + for (PhysRegIndex index = numLogicalIntRegs; + index < numPhysicalIntRegs; + ++index) + { + intScoreboard[index] = 0; + } + + int float_reg_idx = numPhysicalIntRegs; + + // Initialize the entries in the floating point rename map to point to + // the physical registers of the same index, and consider each register + // ready until the first rename occurs. + // Although the index refers purely to architected registers, because + // the floating reg indices come after the integer reg indices, they + // may exceed the size of a normal RegIndex (short). + for (PhysRegIndex index = numLogicalIntRegs; + index < numLogicalRegs; ++index) + { + floatRenameMap[index].physical_reg = float_reg_idx++; + } + + for (PhysRegIndex index = numPhysicalIntRegs; + index < numPhysicalIntRegs + numLogicalFloatRegs; ++index) + { + floatScoreboard[index] = 1; + } + + // Initialize the rest of the physical registers (the ones that don't + // directly map to a logical register) as unready. + for (PhysRegIndex index = numPhysicalIntRegs + numLogicalFloatRegs; + index < numPhysicalRegs; + ++index) + { + floatScoreboard[index] = 0; + } + + // Initialize the entries in the misc register scoreboard to be ready. + for (PhysRegIndex index = numPhysicalRegs; + index < numPhysicalRegs + numMiscRegs; ++index) + { + miscScoreboard[index] = 1; + } +} + +SimpleRenameMap::~SimpleRenameMap() +{ + // Delete the rename maps as they were allocated with new. + delete [] intRenameMap; + delete [] floatRenameMap; +} + +void +SimpleRenameMap::setFreeList(SimpleFreeList *fl_ptr) +{ + //Setup the interface to the freelist. + freeList = fl_ptr; +} + + +// Don't allow this stage to fault; force that check to the rename stage. +// Simply ask to rename a logical register and get back a new physical +// register index. +SimpleRenameMap::RenameInfo +SimpleRenameMap::rename(RegIndex arch_reg) +{ + PhysRegIndex renamed_reg; + PhysRegIndex prev_reg; + + if (arch_reg < numLogicalIntRegs) { + + // Record the current physical register that is renamed to the + // requested architected register. + prev_reg = intRenameMap[arch_reg].physical_reg; + + // If it's not referencing the zero register, then mark the register + // as not ready. + if (arch_reg != intZeroReg) { + // Get a free physical register to rename to. + renamed_reg = freeList->getIntReg(); + + // Update the integer rename map. + intRenameMap[arch_reg].physical_reg = renamed_reg; + + assert(renamed_reg >= 0 && renamed_reg < numPhysicalIntRegs); + + // Mark register as not ready. + intScoreboard[renamed_reg] = false; + } else { + // Otherwise return the zero register so nothing bad happens. + renamed_reg = intZeroReg; + } + } else if (arch_reg < numLogicalRegs) { + // Subtract off the base offset for floating point registers. +// arch_reg = arch_reg - numLogicalIntRegs; + + // Record the current physical register that is renamed to the + // requested architected register. + prev_reg = floatRenameMap[arch_reg].physical_reg; + + // If it's not referencing the zero register, then mark the register + // as not ready. + if (arch_reg != floatZeroReg) { + // Get a free floating point register to rename to. + renamed_reg = freeList->getFloatReg(); + + // Update the floating point rename map. + floatRenameMap[arch_reg].physical_reg = renamed_reg; + + assert(renamed_reg < numPhysicalRegs && + renamed_reg >= numPhysicalIntRegs); + + // Mark register as not ready. + floatScoreboard[renamed_reg] = false; + } else { + // Otherwise return the zero register so nothing bad happens. + renamed_reg = floatZeroReg; + } + } else { + // Subtract off the base offset for miscellaneous registers. + arch_reg = arch_reg - numLogicalRegs; + + // No renaming happens to the misc. registers. They are simply the + // registers that come after all the physical registers; thus + // take the base architected register and add the physical registers + // to it. + renamed_reg = arch_reg + numPhysicalRegs; + + // Set the previous register to the same register; mainly it must be + // known that the prev reg was outside the range of normal registers + // so the free list can avoid adding it. + prev_reg = renamed_reg; + + assert(renamed_reg < numPhysicalRegs + numMiscRegs); + + miscScoreboard[renamed_reg] = false; + } + + return RenameInfo(renamed_reg, prev_reg); +} + +//Perhaps give this a pair as a return value, of the physical register +//and whether or not it's ready. +PhysRegIndex +SimpleRenameMap::lookup(RegIndex arch_reg) +{ + if (arch_reg < numLogicalIntRegs) { + return intRenameMap[arch_reg].physical_reg; + } else if (arch_reg < numLogicalRegs) { + // Subtract off the base FP offset. +// arch_reg = arch_reg - numLogicalIntRegs; + + return floatRenameMap[arch_reg].physical_reg; + } else { + // Subtract off the misc registers offset. + arch_reg = arch_reg - numLogicalRegs; + + // Misc. regs don't rename, so simply add the base arch reg to + // the number of physical registers. + return numPhysicalRegs + arch_reg; + } +} + +bool +SimpleRenameMap::isReady(PhysRegIndex phys_reg) +{ + if (phys_reg < numPhysicalIntRegs) { + return intScoreboard[phys_reg]; + } else if (phys_reg < numPhysicalRegs) { + + // Subtract off the base FP offset. +// phys_reg = phys_reg - numPhysicalIntRegs; + + return floatScoreboard[phys_reg]; + } else { + // Subtract off the misc registers offset. +// phys_reg = phys_reg - numPhysicalRegs; + + return miscScoreboard[phys_reg]; + } +} + +// In this implementation the miscellaneous registers do not actually rename, +// so this function does not allow you to try to change their mappings. +void +SimpleRenameMap::setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg) +{ + if (arch_reg < numLogicalIntRegs) { + DPRINTF(Rename, "Rename Map: Integer register %i being set to %i.\n", + (int)arch_reg, renamed_reg); + + intRenameMap[arch_reg].physical_reg = renamed_reg; + } else { + assert(arch_reg < (numLogicalIntRegs + numLogicalFloatRegs)); + + DPRINTF(Rename, "Rename Map: Float register %i being set to %i.\n", + (int)arch_reg - numLogicalIntRegs, renamed_reg); + + floatRenameMap[arch_reg].physical_reg = renamed_reg; + } +} + +void +SimpleRenameMap::squash(vector<RegIndex> freed_regs, + vector<UnmapInfo> unmaps) +{ + panic("Not sure this function should be called."); + + // Not sure the rename map should be able to access the free list + // like this. + while (!freed_regs.empty()) { + RegIndex free_register = freed_regs.back(); + + if (free_register < numPhysicalIntRegs) { + freeList->addIntReg(free_register); + } else { + // Subtract off the base FP dependence tag. + free_register = free_register - numPhysicalIntRegs; + freeList->addFloatReg(free_register); + } + + freed_regs.pop_back(); + } + + // Take unmap info and roll back the rename map. +} + +void +SimpleRenameMap::markAsReady(PhysRegIndex ready_reg) +{ + DPRINTF(Rename, "Rename map: Marking register %i as ready.\n", + (int)ready_reg); + + if (ready_reg < numPhysicalIntRegs) { + assert(ready_reg >= 0); + + intScoreboard[ready_reg] = 1; + } else if (ready_reg < numPhysicalRegs) { + + // Subtract off the base FP offset. +// ready_reg = ready_reg - numPhysicalIntRegs; + + floatScoreboard[ready_reg] = 1; + } else { + //Subtract off the misc registers offset. +// ready_reg = ready_reg - numPhysicalRegs; + + miscScoreboard[ready_reg] = 1; + } +} + +int +SimpleRenameMap::numFreeEntries() +{ + int free_int_regs = freeList->numFreeIntRegs(); + int free_float_regs = freeList->numFreeFloatRegs(); + + if (free_int_regs < free_float_regs) { + return free_int_regs; + } else { + return free_float_regs; + } +} |