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, 5 insertions, 0 deletions

diff --git a/src/cpu/inorder/resources/cache_unit.cc b/src/cpu/inorder/resources/cache_unit.cc
index 8cd105493..47fafe45a 100644
--- a/src/cpu/inorder/resources/cache_unit.cc
+++ b/src/cpu/inorder/resources/cache_unit.cc
@@ -133,6 +133,11 @@ CacheUnit::getPort(const string &if_name, int idx)
 void
 CacheUnit::init()
 {
+    for (int i = 0; i < width; i++) {
+        reqs[i] = new CacheRequest(this, NULL, 0, 0, 0, 0, 0,
+                                   MemCmd::Command(0), 0, 0, 0);
+    }
+
     // Currently Used to Model TLB Latency. Eventually
     // Switch to Timing TLB translations.
     resourceEvent = new CacheUnitEvent[width];