cpu: remove unnecessary data ptr from O3 internal read() funcs

The read() function merely initiates a memory read operation; the
data doesn't arrive until the access completes and a response packet
is received from the memory system.  Thus there's no need to provide
a data pointer; its existence is historical.

Getting this pointer out of this internal o3 interface sets the
stage for similar cleanup in the ExecContext interface.  Also
found that we were pointlessly setting the contents at this pointer
on a store forward (the useful memcpy happens just a few lines
below the deleted one).

1 files changed, 2 insertions, 8 deletions

diff --git a/src/cpu/o3/lsq_unit.hh b/src/cpu/o3/lsq_unit.hh
index 039bba8b6..b1b0aae3a 100644
--- a/src/cpu/o3/lsq_unit.hh
+++ b/src/cpu/o3/lsq_unit.hh
@@ -511,7 +511,7 @@ class LSQUnit {
   public:
     /** Executes the load at the given index. */
     Fault read(Request *req, Request *sreqLow, Request *sreqHigh,
-               uint8_t *data, int load_idx);
+               int load_idx);
 
     /** Executes the store at the given index. */
     Fault write(Request *req, Request *sreqLow, Request *sreqHigh,
@@ -550,7 +550,7 @@ class LSQUnit {
 template <class Impl>
 Fault
 LSQUnit<Impl>::read(Request *req, Request *sreqLow, Request *sreqHigh,
-                    uint8_t *data, int load_idx)
+                    int load_idx)
 {
     DynInstPtr load_inst = loadQueue[load_idx];
 
@@ -676,12 +676,6 @@ LSQUnit<Impl>::read(Request *req, Request *sreqLow, Request *sreqHigh,
             // Get shift amount for offset into the store's data.
             int shift_amt = req->getVaddr() - storeQueue[store_idx].inst->effAddr;
 
-            if (storeQueue[store_idx].isAllZeros)
-                memset(data, 0, req->getSize());
-            else
-                memcpy(data, storeQueue[store_idx].data + shift_amt,
-                   req->getSize());
-
             // Allocate memory if this is the first time a load is issued.
             if (!load_inst->memData) {
                 load_inst->memData = new uint8_t[req->getSize()];