Add some different parameters. The main change is that the writeback count is now limited so that it doesn't overflow the buffer.

src/cpu/o3/alpha_cpu_builder.cc:
src/cpu/o3/alpha_params.hh:
    Add in dispatchWidth, wbWidth, wbDepth parameters.  wbDepth is the number of cycles of wbWidth instructions that can be buffered.
src/cpu/o3/iew.hh:
    Include separate parameter for dispatch width.
    Also limit the number of outstanding writebacks so the writeback buffer isn't overflowed.  The IQ must make sure with the IEW stage that it can issue instructions prior to issuing.
src/cpu/o3/iew_impl.hh:
    Include separate parameter for dispatch width.
    Also limit the number of outstanding writebacks so the writeback buffer isn't overflowed.
src/cpu/o3/inst_queue_impl.hh:
    IQ needs to check with the IEW to make sure it can issue instructions, and increments the IEW wb counter each time there is an outstanding instruction that will writeback.
src/cpu/o3/lsq_unit_impl.hh:
    Be sure to decrement the writeback counter if there's a squashed load that returned.
src/python/m5/objects/AlphaO3CPU.py:
    Change the parameters to include dispatch width, writeback width, and writeback depth.

--HG--
extra : convert_revision : 31c8cc495273e3c481b79055562fc40f71291fc4

1 files changed, 2 insertions, 0 deletions

diff --git a/src/cpu/o3/inst_queue_impl.hh b/src/cpu/o3/inst_queue_impl.hh
index 1ef1b2cff..61c04cc2b 100644
--- a/src/cpu/o3/inst_queue_impl.hh
+++ b/src/cpu/o3/inst_queue_impl.hh
@@ -686,6 +686,7 @@ InstructionQueue<Impl>::scheduleReadyInsts()
     int total_issued = 0;
 
     while (total_issued < totalWidth &&
+           iewStage->canIssue() &&
            order_it != order_end_it) {
         OpClass op_class = (*order_it).queueType;
 
@@ -783,6 +784,7 @@ InstructionQueue<Impl>::scheduleReadyInsts()
 
             listOrder.erase(order_it++);
             statIssuedInstType[tid][op_class]++;
+            iewStage->incrWb(issuing_inst->seqNum);
         } else {
             statFuBusy[op_class]++;
             fuBusy[tid]++;