O3CPU: Add a hack to ensure that nextPC is set correctly after syscalls.

Just check CPU's nextPC before and after syscall and if it changes,
update this instruction's nextPC because the syscall must have changed
the nextPC.

diff --git a/src/cpu/o3/alpha/dyn_inst_impl.hh b/src/cpu/o3/alpha/dyn_inst_impl.hh
index 6dfe0ccdd3bd4b13db63aba7e969a4c7f197cb30..610a313cfcd39e897480c4752a63c7100e36c076 100644 (file)
--- a/src/cpu/o3/alpha/dyn_inst_impl.hh
+++ b/src/cpu/o3/alpha/dyn_inst_impl.hh
@@ -161,7 +161,15 @@ template <class Impl>
 void
 AlphaDynInst<Impl>::syscall(int64_t callnum)
 {
+    // HACK: check CPU's nextPC before and after syscall. If it
+    // changes, update this instruction's nextPC because the syscall
+    // must have changed the nextPC.
+    Addr cpu_next_pc = this->cpu->readNextPC(this->threadNumber);
     this->cpu->syscall(callnum, this->threadNumber);
+    Addr new_next_pc = this->cpu->readNextPC(this->threadNumber);
+    if (cpu_next_pc != new_next_pc) {
+        this->setNextPC(new_next_pc);
+    }
 }
 #endif