cpu-o3: In reg arbitration, give smaller value higher priority (#224)

Change-Id: I723ce9d0299a6640607dd75c791075cba59cb1ab
OpenXiangShan · Dec 11, 2024 · 8eb80f7 · 8eb80f7
1 parent 5cae0e5
commit 8eb80f7
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Showing 2 changed files with 2 additions and 1 deletion.
diff --git a/configs/common/FUScheduler.py b/configs/common/FUScheduler.py
@@ -9,6 +9,7 @@
 #  must be consistent with issue_queue.cc
 maxTotalRFPorts = (1 << 6) - 1
 # portid, priority
+# smaller value get higher priority
 def IntRD(id, p):
     # [7:6] [5:2] [1:0]
     assert id < 16

diff --git a/src/cpu/o3/issue_queue.cc b/src/cpu/o3/issue_queue.cc
@@ -934,7 +934,7 @@ Scheduler::useRegfilePort(const DynInstPtr& inst, const PhysRegIdPtr& regid, int
     }
     assert(typePortId < rfPortOccupancy.size());
     if (rfPortOccupancy[typePortId].first) {
-        if (rfPortOccupancy[typePortId].second > pri) {
+        if (rfPortOccupancy[typePortId].second < pri) { // smaller is higher priority
             // inst arbitration failure
             arbFailedInsts.push_back(inst);
             DPRINTF(Schedule, "[sn:%llu] arbitration failure, typePortId %d occupied by [sn:%llu]\n", inst->seqNum, typePortId,