fixed inefficient code for compiling complimented bit.

[fw/sdcc] / src / pic16 / ralloc.c

diff --git a/src/pic16/ralloc.c b/src/pic16/ralloc.c
index 0fec45041ddb85bb4eeb038038336b8081022444..e898f471becf10eddafadd2a3ccaa7044404f415 100644 (file)
--- a/src/pic16/ralloc.c
+++ b/src/pic16/ralloc.c
@@ -3800,6 +3800,45 @@ pic16_packRegisters (eBBlock * ebp)
        debugLog ("  %d - Pointer set\n", __LINE__);
 
 
+               /* Look for two subsequent iCodes with */
+               /*   iTemp := _c;         */
+               /*   _c = iTemp & op;     */
+               /* and replace them by    */
+               /*   iTemp := _c;         */
+               /*   _c = _c & op;        */
+               if ((ic->op == BITWISEAND || ic->op == '|' || ic->op == '^') &&
+                       ic->prev &&
+                       ic->prev->op == '=' &&
+                       IS_ITEMP (IC_LEFT (ic)) &&
+                       IC_LEFT (ic) == IC_RESULT (ic->prev) &&
+                       isOperandEqual (IC_RESULT(ic), IC_RIGHT(ic->prev)))
+        {
+                       iCode* ic_prev = ic->prev;
+                       symbol* prev_result_sym = OP_SYMBOL (IC_RESULT (ic_prev));
+                       
+                       ReplaceOpWithCheaperOp (&IC_LEFT (ic), IC_RESULT (ic));
+                       if (IC_RESULT (ic_prev) != IC_RIGHT (ic))
+            {
+                               bitVectUnSetBit (OP_USES (IC_RESULT (ic_prev)), ic->key);
+                               if (/*IS_ITEMP (IC_RESULT (ic_prev)) && */
+                                       prev_result_sym->liveTo == ic->seq)
+                {
+                                       prev_result_sym->liveTo = ic_prev->seq;
+                }
+            }
+                       bitVectSetBit (OP_USES (IC_RESULT (ic)), ic->key);
+                       
+                       bitVectSetBit (ic->rlive, IC_RESULT (ic)->key);
+                       
+                       if (bitVectIsZero (OP_USES (IC_RESULT (ic_prev))))
+            {
+                               bitVectUnSetBit (ic->rlive, IC_RESULT (ic)->key);
+                               bitVectUnSetBit (OP_DEFS (IC_RESULT (ic_prev)), ic_prev->key);
+                               remiCodeFromeBBlock (ebp, ic_prev);
+                               hTabDeleteItem (&iCodehTab, ic_prev->key, ic_prev, DELETE_ITEM, NULL);
+            }
+        }
+               
     /* if this is an itemp & result of a address of a true sym 
        then mark this as rematerialisable   */
     if (ic->op == ADDRESS_OF &&