cpu: nullptr in a DPRINTF statement

This change fixes the crashing of gem5 when `Branch` debug flag is enabled. A DPRINTF statement had a nullptr. This change prints `INVALID_TARGET` if the nullptr is encountered. Signed-off-by: Kaustav Goswami <[email protected]> Change-Id: I40bd42c07de25a493a3dd1094a2fd8cc0ce0a79b Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/59109 Tested-by: kokoro <[email protected]> Reviewed-by: Jason Lowe-Power <[email protected]> Maintainer: Jason Lowe-Power <[email protected]>
plctlab · Apr 28, 2022 · fda0759 · fda0759
1 parent f8589a4
commit fda0759
Showing 1 changed file with 13 additions and 4 deletions.
diff --git a/src/cpu/pred/bpred_unit.cc b/src/cpu/pred/bpred_unit.cc
@@ -335,10 +335,19 @@ BPredUnit::squash(const InstSeqNum &squashed_sn, ThreadID tid)
     while (!pred_hist.empty() &&
            pred_hist.front().seqNum > squashed_sn) {
         if (pred_hist.front().usedRAS) {
-            DPRINTF(Branch, "[tid:%i] [squash sn:%llu]"
-                    " Restoring top of RAS to: %i,"
-                    " target: %s\n", tid, squashed_sn,
-                    pred_hist.front().RASIndex, *pred_hist.front().RASTarget);
+            if (pred_hist.front().RASTarget != nullptr) {
+                DPRINTF(Branch, "[tid:%i] [squash sn:%llu]"
+                        " Restoring top of RAS to: %i,"
+                        " target: %s\n", tid, squashed_sn,
+                        pred_hist.front().RASIndex,
+                        *pred_hist.front().RASTarget);
+            }
+            else {
+                DPRINTF(Branch, "[tid:%i] [squash sn:%llu]"
+                        " Restoring top of RAS to: %i,"
+                        " target: INVALID_TARGET\n", tid, squashed_sn,
+                        pred_hist.front().RASIndex);
+            }
 
             RAS[tid].restore(pred_hist.front().RASIndex,
                              pred_hist.front().RASTarget.get());