O3: Send instruction back to fetch on squash to seed predecoder correctly.

3 files changed, 9 insertions, 5 deletions

diff --git a/src/cpu/o3/cpu.cc b/src/cpu/o3/cpu.cc
index 2d3bc3f72..4088f2399 100644
--- a/src/cpu/o3/cpu.cc
+++ b/src/cpu/o3/cpu.cc
@@ -808,8 +808,9 @@ FullO3CPU<Impl>::removeThread(ThreadID tid)
     }
 
     // Squash Throughout Pipeline
-    InstSeqNum squash_seq_num = commit.rob->readHeadInst(tid)->seqNum;
-    fetch.squash(0, squash_seq_num, tid);
+    DynInstPtr inst = commit.rob->readHeadInst(tid);
+    InstSeqNum squash_seq_num = inst->seqNum;
+    fetch.squash(0, squash_seq_num, inst, tid);
     decode.squash(tid);
     rename.squash(squash_seq_num, tid);
     iew.squash(tid);
diff --git a/src/cpu/o3/fetch.hh b/src/cpu/o3/fetch.hh
index c51658104..4a4ac0902 100644
--- a/src/cpu/o3/fetch.hh
+++ b/src/cpu/o3/fetch.hh
@@ -312,8 +312,8 @@ class DefaultFetch
      * remove any instructions that are not in the ROB. The source of this
      * squash should be the commit stage.
      */
-    void squash(const TheISA::PCState &newPC,
-                const InstSeqNum &seq_num, ThreadID tid);
+    void squash(const TheISA::PCState &newPC, const InstSeqNum &seq_num,
+                DynInstPtr &squashInst, ThreadID tid);
 
     /** Ticks the fetch stage, processing all inputs signals and fetching
      * as many instructions as possible.
diff --git a/src/cpu/o3/fetch_impl.hh b/src/cpu/o3/fetch_impl.hh
index 5f9be039f..6c1ac456d 100644
--- a/src/cpu/o3/fetch_impl.hh
+++ b/src/cpu/o3/fetch_impl.hh
@@ -815,11 +815,14 @@ DefaultFetch<Impl>::updateFetchStatus()
 template <class Impl>
 void
 DefaultFetch<Impl>::squash(const TheISA::PCState &newPC,
-                           const InstSeqNum &seq_num, ThreadID tid)
+                           const InstSeqNum &seq_num, DynInstPtr &squashInst,
+                           ThreadID tid)
 {
     DPRINTF(Fetch, "[tid:%u]: Squash from commit.\n", tid);
 
     doSquash(newPC, tid);
+    if (squashInst)
+        predecoder.reset(squashInst->staticInst->machInst);
 
     // Tell the CPU to remove any instructions that are not in the ROB.
     cpu->removeInstsNotInROB(tid);