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authorKevin Lim <ktlim@umich.edu>2004-08-20 14:54:07 -0400
committerKevin Lim <ktlim@umich.edu>2004-08-20 14:54:07 -0400
commit04745696b6b523c5e90c335298099600d4a14a76 (patch)
tree66b578f8c44355ccf8e970fe59b52554dde9d0ce /cpu/beta_cpu/rob_impl.hh
parent8295a8050c1096dc560f4976724adada810e56e1 (diff)
downloadgem5-04745696b6b523c5e90c335298099600d4a14a76.tar.xz
Check in of new CPU. This checkin works under non-Fullsystem mode, with no caches.
SConscript: Added new CPU files to build. arch/alpha/isa_desc: Changed rduniq and wruniq to be nonspeculative because the uniq register is not renamed. arch/isa_parser.py: Added new CPU exec method. base/statistics.hh: Minor change for namespace conflict. Probably can change back one the new CPU files are cleaned up. base/traceflags.py: Added new CPU trace flags. cpu/static_inst.hh: Changed static inst to use a file that defines the execute functions. --HG-- extra : convert_revision : bd4ce34361308280168324817fc1258dd253e519
Diffstat (limited to 'cpu/beta_cpu/rob_impl.hh')
-rw-r--r--cpu/beta_cpu/rob_impl.hh264
1 files changed, 264 insertions, 0 deletions
diff --git a/cpu/beta_cpu/rob_impl.hh b/cpu/beta_cpu/rob_impl.hh
new file mode 100644
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+++ b/cpu/beta_cpu/rob_impl.hh
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+#ifndef __ROB_IMPL_HH__
+#define __ROB_IMPL_HH__
+
+#include "cpu/beta_cpu/rob.hh"
+
+template<class Impl>
+ROB<Impl>::ROB(unsigned _numEntries, unsigned _squashWidth)
+ : numEntries(_numEntries),
+ squashWidth(_squashWidth),
+ numInstsInROB(0),
+ squashedSeqNum(0)
+{
+ doneSquashing = true;
+}
+
+template<class Impl>
+void
+ROB<Impl>::setCPU(FullCPU *cpu_ptr)
+{
+ cpu = cpu_ptr;
+
+ tail = cpu->instList.begin();
+
+ squashIt = cpu->instList.end();
+}
+
+template<class Impl>
+int
+ROB<Impl>::countInsts()
+{
+/*
+ int return_val = 0;
+
+ // Iterate through the ROB from the head to the tail, counting the
+ // entries.
+ for (InstIt i = cpu->instList.begin(); i != tail; i++)
+ {
+ assert(i != cpu->instList.end());
+ return_val++;
+ }
+
+ return return_val;
+*/
+ // Because the head won't be tracked properly until the ROB gets the
+ // first instruction, and any time that the ROB is empty and has not
+ // yet gotten the instruction, this function doesn't work.
+ return numInstsInROB;
+}
+
+template<class Impl>
+void
+ROB<Impl>::insertInst(DynInst *inst)
+{
+ // Make sure we have the right number of instructions.
+ assert(numInstsInROB == countInsts());
+ // Make sure the instruction is valid.
+ assert(inst);
+
+ DPRINTF(ROB, "ROB: Adding inst PC %#x to the ROB.\n", inst->readPC());
+
+ // If the ROB is full then exit.
+ assert(numInstsInROB != numEntries);
+
+ ++numInstsInROB;
+
+ // Increment the tail iterator, moving it one instruction back.
+ // There is a special case if the ROB was empty prior to this insertion,
+ // in which case the tail will be pointing at instList.end(). If that
+ // happens, then reset the tail to the beginning of the list.
+ if (tail != cpu->instList.end()) {
+ tail++;
+ } else {
+ tail = cpu->instList.begin();
+ }
+
+ // Make sure the tail iterator is actually pointing at the instruction
+ // added.
+ assert((*tail) == inst);
+
+ DPRINTF(ROB, "ROB: Now has %d instructions.\n", numInstsInROB);
+
+}
+
+// Whatever calls this function needs to ensure that it properly frees up
+// registers prior to this function.
+template<class Impl>
+void
+ROB<Impl>::retireHead()
+{
+ assert(numInstsInROB == countInsts());
+
+ DynInst *head_inst;
+
+ // Get the head ROB instruction.
+ head_inst = cpu->instList.front();
+
+ // Make certain this can retire.
+ assert(head_inst->readyToCommit());
+
+ DPRINTF(ROB, "ROB: Retiring head instruction of the ROB, "
+ "instruction PC %#x, seq num %i\n", head_inst->readPC(),
+ head_inst->seqNum);
+
+ // Keep track of how many instructions are in the ROB.
+ --numInstsInROB;
+
+ // Tell CPU to remove the instruction from the list of instructions.
+ // A special case is needed if the instruction being retired is the
+ // only instruction in the ROB; otherwise the tail iterator will become
+ // invalidated.
+ if (tail == cpu->instList.begin()) {
+ cpu->removeFrontInst(head_inst);
+ tail = cpu->instList.end();
+ } else {
+ cpu->removeFrontInst(head_inst);
+ }
+}
+
+template<class Impl>
+bool
+ROB<Impl>::isHeadReady()
+{
+ if (numInstsInROB != 0) {
+ DynInst *head_inst = cpu->instList.front();
+
+ return head_inst->readyToCommit();
+ }
+
+ return false;
+}
+
+template<class Impl>
+unsigned
+ROB<Impl>::numFreeEntries()
+{
+ assert(numInstsInROB == countInsts());
+
+ return numEntries - numInstsInROB;
+}
+
+template<class Impl>
+void
+ROB<Impl>::doSquash()
+{
+ DPRINTF(ROB, "ROB: Squashing instructions.\n");
+
+ assert(squashIt != cpu->instList.end());
+
+ for (int numSquashed = 0;
+ numSquashed < squashWidth && (*squashIt)->seqNum != squashedSeqNum;
+ ++numSquashed)
+ {
+ // Ensure that the instruction is younger.
+ assert((*squashIt)->seqNum > squashedSeqNum);
+
+ DPRINTF(ROB, "ROB: Squashing instruction PC %#x, seq num %i.\n",
+ (*squashIt)->readPC(), (*squashIt)->seqNum);
+
+ // Mark the instruction as squashed, and ready to commit so that
+ // it can drain out of the pipeline.
+ (*squashIt)->setSquashed();
+
+ (*squashIt)->setCanCommit();
+
+#ifndef FULL_SYSTEM
+ if (squashIt == cpu->instList.begin()) {
+ DPRINTF(ROB, "ROB: Reached head of instruction list while "
+ "squashing.\n");
+
+ squashIt = cpu->instList.end();
+
+ doneSquashing = true;
+
+ return;
+ }
+#endif
+
+ // Move the tail iterator to the next instruction.
+ squashIt--;
+ }
+
+
+ // Check if ROB is done squashing.
+ if ((*squashIt)->seqNum == squashedSeqNum) {
+ DPRINTF(ROB, "ROB: Done squashing instructions.\n");
+
+ squashIt = cpu->instList.end();
+
+ doneSquashing = true;
+ }
+}
+
+template<class Impl>
+void
+ROB<Impl>::squash(InstSeqNum squash_num)
+{
+ DPRINTF(ROB, "ROB: Starting to squash within the ROB.\n");
+ doneSquashing = false;
+
+ squashedSeqNum = squash_num;
+
+ assert(tail != cpu->instList.end());
+
+ squashIt = tail;
+
+ doSquash();
+}
+
+template<class Impl>
+uint64_t
+ROB<Impl>::readHeadPC()
+{
+ assert(numInstsInROB == countInsts());
+
+ DynInst *head_inst = cpu->instList.front();
+
+ return head_inst->readPC();
+}
+
+template<class Impl>
+uint64_t
+ROB<Impl>::readHeadNextPC()
+{
+ assert(numInstsInROB == countInsts());
+
+ DynInst *head_inst = cpu->instList.front();
+
+ return head_inst->readNextPC();
+}
+
+template<class Impl>
+InstSeqNum
+ROB<Impl>::readHeadSeqNum()
+{
+ // Return the last sequence number that has not been squashed. Other
+ // stages can use it to squash any instructions younger than the current
+ // tail.
+ DynInst *head_inst = cpu->instList.front();
+
+ return head_inst->seqNum;
+}
+
+template<class Impl>
+uint64_t
+ROB<Impl>::readTailPC()
+{
+ assert(numInstsInROB == countInsts());
+
+ assert(tail != cpu->instList.end());
+
+ return (*tail)->readPC();
+}
+
+template<class Impl>
+InstSeqNum
+ROB<Impl>::readTailSeqNum()
+{
+ // Return the last sequence number that has not been squashed. Other
+ // stages can use it to squash any instructions younger than the current
+ // tail.
+ return (*tail)->seqNum;
+}
+
+#endif // __ROB_IMPL_HH__