o3: split load & store queue full cases in rename

Check for free entries in Load Queue and Store Queue separately to
avoid cases when load cannot be renamed due to full Store Queue and
vice versa.

This work was done while Binh was an intern at AMD Research.

1 files changed, 28 insertions, 16 deletions

diff --git a/src/cpu/o3/iew_impl.hh b/src/cpu/o3/iew_impl.hh
index 644366dfc..20d3a1c36 100644
--- a/src/cpu/o3/iew_impl.hh
+++ b/src/cpu/o3/iew_impl.hh
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2010-2013 ARM Limited
+ * Copyright (c) 2013 Advanced Micro Devices, Inc.
  * All rights reserved.
  *
  * The license below extends only to copyright in the software and shall
@@ -315,8 +316,8 @@ DefaultIEW<Impl>::startupStage()
             instQueue.numFreeEntries(tid);
 
         toRename->iewInfo[tid].usedLSQ = true;
-        toRename->iewInfo[tid].freeLSQEntries =
-            ldstQueue.numFreeEntries(tid);
+        toRename->iewInfo[tid].freeLQEntries = ldstQueue.numFreeLoadEntries(tid);
+        toRename->iewInfo[tid].freeSQEntries = ldstQueue.numFreeStoreEntries(tid);
     }
 
     // Initialize the checker's dcache port here
@@ -467,9 +468,11 @@ DefaultIEW<Impl>::squash(ThreadID tid)
             tid, fromCommit->commitInfo[tid].doneSeqNum);
 
     while (!skidBuffer[tid].empty()) {
-        if (skidBuffer[tid].front()->isLoad() ||
-            skidBuffer[tid].front()->isStore() ) {
-            toRename->iewInfo[tid].dispatchedToLSQ++;
+        if (skidBuffer[tid].front()->isLoad()) {
+            toRename->iewInfo[tid].dispatchedToLQ++;
+        }
+        if (skidBuffer[tid].front()->isStore()) {
+            toRename->iewInfo[tid].dispatchedToSQ++;
         }
 
         toRename->iewInfo[tid].dispatched++;
@@ -903,9 +906,11 @@ DefaultIEW<Impl>::emptyRenameInsts(ThreadID tid)
 
     while (!insts[tid].empty()) {
 
-        if (insts[tid].front()->isLoad() ||
-            insts[tid].front()->isStore() ) {
-            toRename->iewInfo[tid].dispatchedToLSQ++;
+        if (insts[tid].front()->isLoad()) {
+            toRename->iewInfo[tid].dispatchedToLQ++;
+        }
+        if (insts[tid].front()->isStore()) {
+            toRename->iewInfo[tid].dispatchedToSQ++;
         }
 
         toRename->iewInfo[tid].dispatched++;
@@ -1043,9 +1048,13 @@ DefaultIEW<Impl>::dispatchInsts(ThreadID tid)
             insts_to_dispatch.pop();
 
             //Tell Rename That An Instruction has been processed
-            if (inst->isLoad() || inst->isStore()) {
-                toRename->iewInfo[tid].dispatchedToLSQ++;
+            if (inst->isLoad()) {
+                toRename->iewInfo[tid].dispatchedToLQ++;
             }
+            if (inst->isStore()) {
+                toRename->iewInfo[tid].dispatchedToSQ++;
+            }
+
             toRename->iewInfo[tid].dispatched++;
 
             continue;
@@ -1093,7 +1102,7 @@ DefaultIEW<Impl>::dispatchInsts(ThreadID tid)
 
             add_to_iq = true;
 
-            toRename->iewInfo[tid].dispatchedToLSQ++;
+            toRename->iewInfo[tid].dispatchedToLQ++;
         } else if (inst->isStore()) {
             DPRINTF(IEW, "[tid:%i]: Issue: Memory instruction "
                     "encountered, adding to LSQ.\n", tid);
@@ -1116,7 +1125,7 @@ DefaultIEW<Impl>::dispatchInsts(ThreadID tid)
                 add_to_iq = true;
             }
 
-            toRename->iewInfo[tid].dispatchedToLSQ++;
+            toRename->iewInfo[tid].dispatchedToSQ++;
         } else if (inst->isMemBarrier() || inst->isWriteBarrier()) {
             // Same as non-speculative stores.
             inst->setCanCommit();
@@ -1613,8 +1622,11 @@ DefaultIEW<Impl>::tick()
             toRename->iewInfo[tid].freeIQEntries =
                 instQueue.numFreeEntries(tid);
             toRename->iewInfo[tid].usedLSQ = true;
-            toRename->iewInfo[tid].freeLSQEntries =
-                ldstQueue.numFreeEntries(tid);
+
+            toRename->iewInfo[tid].freeLQEntries =
+                ldstQueue.numFreeLoadEntries(tid);
+            toRename->iewInfo[tid].freeSQEntries =
+                ldstQueue.numFreeStoreEntries(tid);
 
             wroteToTimeBuffer = true;
         }
@@ -1624,9 +1636,9 @@ DefaultIEW<Impl>::tick()
     }
 
     DPRINTF(IEW, "IQ has %i free entries (Can schedule: %i).  "
-            "LSQ has %i free entries.\n",
+            "LQ has %i free entries. SQ has %i free entries.\n",
             instQueue.numFreeEntries(), instQueue.hasReadyInsts(),
-            ldstQueue.numFreeEntries());
+            ldstQueue.numFreeLoadEntries(), ldstQueue.numFreeStoreEntries());
 
     updateStatus();