inorder: initialize res. req. vectors based on resource bandwidth

first change in an optimization that will stop InOrder from allocating new memory for every instruction's
request to a resource. This gets expensive since every instruction needs to access ~10 requests before
graduation. Instead, the plan is to allocate just enough resource request objects to satisfy each resource's
bandwidth (e.g. the execution unit would need to allocate 3 resource request objects for a 1-issue pipeline
since on any given cycle it could have 2 read requests and 1 write request) and then let the instructions
contend and reuse those allocated requests. The end result is a smaller memory footprint for the InOrder model
and increased simulation performance

1 files changed, 13 insertions, 0 deletions

diff --git a/src/cpu/inorder/resources/use_def.cc b/src/cpu/inorder/resources/use_def.cc
index 538b20246..dd178403b 100644
--- a/src/cpu/inorder/resources/use_def.cc
+++ b/src/cpu/inorder/resources/use_def.cc
@@ -88,6 +88,19 @@ UseDefUnit::regStats()
     Resource::regStats();
 }
 
+void
+UseDefUnit::init()
+{
+    // Set Up Resource Events to Appropriate Resource BandWidth
+    resourceEvent = new ResourceEvent[width];
+
+    for (int i = 0; i < width; i++) {
+        reqs[i] = new UseDefRequest(this, NULL, 0, 0, 0, 0, 0);
+    }
+
+    initSlots();
+}
+
 ResReqPtr
 UseDefUnit::getRequest(DynInstPtr inst, int stage_num, int res_idx,
                      int slot_num, unsigned cmd)