ARM: Add support for moving predicated false dest operands from sources.

3 files changed, 19 insertions, 0 deletions

diff --git a/src/cpu/o3/dyn_inst.hh b/src/cpu/o3/dyn_inst.hh
index b62068111..487c284e6 100644
--- a/src/cpu/o3/dyn_inst.hh
+++ b/src/cpu/o3/dyn_inst.hh
@@ -181,6 +181,18 @@ class BaseO3DynInst : public BaseDynInst<Impl>
         this->thread->inSyscall = in_syscall;
     }
 
+    void forwardOldRegs()
+    {
+
+        for (int idx = 0; idx < this->numDestRegs(); idx++) {
+            PhysRegIndex prev_phys_reg = this->prevDestRegIdx(idx);
+            TheISA::RegIndex original_dest_reg = this->staticInst->destRegIdx(idx);
+            if (original_dest_reg <  TheISA::FP_Base_DepTag)
+                this->setIntRegOperand(this->staticInst.get(), idx, this->cpu->readIntReg(prev_phys_reg));
+            else if (original_dest_reg < TheISA::Ctrl_Base_DepTag)
+                this->setFloatRegOperandBits(this->staticInst.get(), idx, this->cpu->readFloatRegBits(prev_phys_reg));
+        }
+    }
 #if FULL_SYSTEM
     /** Calls hardware return from error interrupt. */
     Fault hwrei();
diff --git a/src/cpu/o3/iew_impl.hh b/src/cpu/o3/iew_impl.hh
index 2acb941e0..e1af20852 100644
--- a/src/cpu/o3/iew_impl.hh
+++ b/src/cpu/o3/iew_impl.hh
@@ -1261,6 +1261,8 @@ DefaultIEW<Impl>::executeInsts()
             // will be replaced and we will lose it.
             if (inst->getFault() == NoFault) {
                 inst->execute();
+                if (inst->readPredicate() == false)
+                    inst->forwardOldRegs();
             }
 
             inst->setExecuted();
diff --git a/src/cpu/o3/lsq_unit_impl.hh b/src/cpu/o3/lsq_unit_impl.hh
index 64d674666..7be5e4e5b 100644
--- a/src/cpu/o3/lsq_unit_impl.hh
+++ b/src/cpu/o3/lsq_unit_impl.hh
@@ -458,6 +458,8 @@ LSQUnit<Impl>::executeLoad(DynInstPtr &inst)
         // realizes there is activity.
         // Mark it as executed unless it is an uncached load that
         // needs to hit the head of commit.
+        if (inst->readPredicate() == false)
+            inst->forwardOldRegs();
         DPRINTF(LSQUnit, "Load [sn:%lli] not executed from %s\n",
                 inst->seqNum,
                 (load_fault != NoFault ? "fault" : "predication"));
@@ -530,6 +532,9 @@ LSQUnit<Impl>::executeStore(DynInstPtr &store_inst)
 
     Fault store_fault = store_inst->initiateAcc();
 
+    if (store_inst->readPredicate() == false)
+        store_inst->forwardOldRegs();
+
     if (storeQueue[store_idx].size == 0) {
         DPRINTF(LSQUnit,"Fault on Store PC %s, [sn:%lli], Size = 0\n",
                 store_inst->pcState(), store_inst->seqNum);