* src/SDCCglue.c (printChar): fixed bug #973350, patch provided by Phuah Yee Keat...

[fw/sdcc] / src / SDCCloop.c

diff --git a/src/SDCCloop.c b/src/SDCCloop.c
index ef902a31db34666905e4353dd7078146e3d806f9..52cc19affc7c0ef5a1e9c124a9ae442710bd6f04 100644 (file)
--- a/src/SDCCloop.c
+++ b/src/SDCCloop.c
@@ -46,7 +46,7 @@ newInduction (operand * sym, unsigned int op,
   ip->op = op;
   ip->cval = constVal;
   ip->ic = ic;
-  updateSpillLocation(ic,1);
+//updateSpillLocation(ic,1);
   return ip;
 }
 
@@ -131,7 +131,7 @@ intersectLoopSucc (set * lexits, eBBlock ** ebbs)
 
   if (!exit)
     return NULL;
-
+  
   succVect = bitVectCopy (exit->succVect);
 
   for (exit = setNextItem (lexits); exit;
@@ -235,7 +235,6 @@ DEFSETFUNC (addToExitsMarkDepth)
   if (ebp->depth<depth)
     ebp->depth = depth;
 
-  /* put the loop region info in the block */
   /* NOTE: here we will update only the inner most loop
      that it is a part of */
   if (!ebp->partOfLoop)
@@ -307,7 +306,7 @@ DEFSETFUNC (addDefInExprs)
   V_ARG (int, count);
 
   addSetHead (&ebp->inExprs, cdp);
-  cseBBlock (ebp, 0, ebbs, count);
+  cseBBlock (ebp, optimize.global_cse, ebbs, count);
   return 0;
 }
 
@@ -329,7 +328,7 @@ assignmentsToSym (set * sset, operand * sym)
          in this block */
       bitVect *defs = bitVectIntersect (ebp->ldefs, OP_DEFS (sym));
       assigns += bitVectnBitsOn (defs);
-      setToNull ((void **) &defs);
+      setToNull ((void *) &defs);
 
     }
 
@@ -380,7 +379,22 @@ DEFSETFUNC (pointerAssigned)
   eBBlock *ebp = item;
   V_ARG (operand *, op);
 
-  return ebp->hasFcall || bitVectBitValue (ebp->ptrsSet, op->key);
+  if (ebp->hasFcall)
+    return 1;
+
+  if (bitVectBitValue (ebp->ptrsSet, op->key))
+    return 1;
+
+  /* Unfortunately, one of the other pointer set operations  */
+  /* may be using an alias of this operand, and the above    */
+  /* test would miss it. To be thorough, some aliasing       */
+  /* analysis should be done here. In the meantime, be       */
+  /* conservative and assume any other pointer set operation */
+  /* is dangerous                                            */
+  if (!bitVectIsZero (ebp->ptrsSet))
+    return 1;
+  
+  return 0;
 }
 
 /*-----------------------------------------------------------------*/
@@ -446,7 +460,7 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count)
          int lin, rin;
          cseDef *ivar;
 
-         /* jwk: TODO this is only needed if the call is between
+         /* TODO this is only needed if the call is between
             here and the definition, but I am too lazy to do that now */
 
          /* if there are function calls in this block */
@@ -465,6 +479,13 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count)
 
          if (SKIP_IC (ic) || POINTER_SET (ic) || ic->op == IFX)
            continue;
+         
+         /* iTemp assignment from a literal may be invariant, but it
+            will needlessly increase register pressure if the
+            iCode(s) that use this iTemp are not also invariant */
+         if (ic->op=='=' && IS_ITEMP (IC_RESULT (ic))
+             && IS_OP_LITERAL (IC_RIGHT (ic)))
+           continue;
 
          /* if result is volatile then skip */
          if (IC_RESULT (ic) &&
@@ -508,7 +529,8 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count)
              applyToSet (theLoop->regBlocks, hasNonPtrUse, IC_LEFT (ic)))
            continue;
 
-         /* if both the left & right are invariants : then check that */
+
+          /* if both the left & right are invariants : then check that */
          /* this definition exists in the out definition of all the  */
          /* blocks, this will ensure that this is not assigned any   */
          /* other value in the loop , and not used in this block     */
@@ -519,7 +541,7 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count)
              eBBlock *sBlock;
              set *lSet = setFromSet (theLoop->regBlocks);
 
-             /* if this block does not dominate all exists */
+             /* if this block does not dominate all exits */
              /* make sure this defintion is not used anywhere else */
              if (!domsAllExits)
                {
@@ -568,7 +590,9 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count)
              /* now we know it is a true invariant */
              /* remove it from the insts chain & put */
              /* in the invariant set                */
-             OP_SYMBOL (IC_RESULT (ic))->isinvariant = 1;
+             
+              OP_SYMBOL (IC_RESULT (ic))->isinvariant = 1;
+              SPIL_LOC (IC_RESULT (ic)) = NULL;
              remiCodeFromeBBlock (lBlock, ic);
 
              /* maintain the data flow */
@@ -818,7 +842,6 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count)
          if (nexits == 1)
            {
              eBBlock *exit = setFirstItem (loopReg->exits);
-
              /* if it is the same block then there is no
                 need to move it about */
              if (exit != lBlock)
@@ -856,7 +879,18 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count)
                      if (bitVectBitValue (loopSuccs, i))
                        {
 
-                         eBBlock *eblock = ebbs[i];
+                         eBBlock *eblock = NULL;
+                         int j;
+                         
+                         /* Need to search for bbnum == i since ebbs is  */
+                         /* sorted by dfnum; a direct index won't do.  */
+                         for (j=0; j<count; j++)
+                           if (ebbs[j]->bbnum == i)
+                             {
+                               eblock = ebbs[j];
+                               break;
+                             }
+                         assert(eblock);
 
                          /* if the successor does not belong to the loop
                             and will be executed after the loop : then
@@ -868,9 +902,9 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count)
                              iCode *newic = newiCode ('=', NULL,
                                        operandFromOperand (IC_RIGHT (ic)));
                              IC_RESULT (newic) = operandFromOperand (IC_RESULT (ic));
-                             OP_DEFS (IC_RESULT (newic)) =
+                             OP_DEFS(IC_RESULT (newic))=
                                bitVectSetBit (OP_DEFS (IC_RESULT (newic)), newic->key);
-                             OP_USES (IC_RIGHT (newic)) =
+                             OP_USES(IC_RIGHT (newic))=
                                bitVectSetBit (OP_USES (IC_RIGHT (newic)), newic->key);
                              /* and add it */
                              if (eblock->sch && eblock->sch->op == LABEL)
@@ -1057,7 +1091,7 @@ loopInduction (region * loopReg, eBBlock ** ebbs, int count)
       lastBlock->linds = bitVectUnion(lastBlock->linds,indVect);
     }
 
-  setToNull ((void **) &indVars);
+  setToNull ((void *) &indVars);
   return change;
 }
 
@@ -1085,7 +1119,7 @@ DEFSETFUNC (mergeRegions)
       if (lp->entry == theLoop->entry)
        {
          theLoop->regBlocks = unionSets (theLoop->regBlocks,
-                                         lp->regBlocks, THROW_BOTH);
+                                         lp->regBlocks, THROW_DEST);
          lp->merged = 1;
        }
     }
@@ -1168,6 +1202,7 @@ createLoopRegions (eBBlock ** ebbs, int count)
 
   applyToSet (allRegion, mergeInnerLoops, allRegion, &maxDepth);
   maxDepth++;
+
   /* now create all the exits .. also */
   /* create an ordered set of loops   */
   /* i.e. we process loops in the inner to outer order */