Fixed a number of problems revealed by bug #827883.

[fw/sdcc] / src / SDCCloop.c

diff --git a/src/SDCCloop.c b/src/SDCCloop.c
index 7ab87a7ff8277d62140a6b17be62365b2b250715..1ff5e2cdb59c8b24988aafdd4247dd2f8a8c61b1 100644 (file)
--- a/src/SDCCloop.c
+++ b/src/SDCCloop.c
@@ -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);
 
     }
 
@@ -446,15 +445,32 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count)
          int lin, rin;
          cseDef *ivar;
 
-         /* if there are function calls in this block and this
-            is a pointer get, the function could have changed it
-            so skip, ISO-C99 according to David A. Long */
-         if (fCallsInBlock && POINTER_GET(ic)) {
-           continue;
+         /* 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 */
+         if (fCallsInBlock) {
+
+           /* if this is a pointer get */
+           if (POINTER_GET(ic)) {
+             continue;
+           }
+
+           /* if this is an assignment from a global */
+           if (ic->op=='=' && isOperandGlobal(IC_RIGHT(ic))) {
+             continue;
+           }
          }
 
          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) &&
@@ -498,7 +514,8 @@ 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     */
@@ -509,7 +526,7 @@ 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)
                {
@@ -558,7 +575,9 @@ 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 */
@@ -858,9 +877,9 @@ 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)
@@ -1044,10 +1063,10 @@ loopInduction (region * loopReg, eBBlock ** ebbs, int count)
       /* add the induction variable vector to the last
          block in the loop */
       lastBlock->isLastInLoop = 1;
-      lastBlock->linds = indVect;
+      lastBlock->linds = bitVectUnion(lastBlock->linds,indVect);
     }
 
-  setToNull ((void **) &indVars);
+  setToNull ((void *) &indVars);
   return change;
 }
 
@@ -1075,7 +1094,7 @@ DEFSETFUNC (mergeRegions)
       if (lp->entry == theLoop->entry)
        {
          theLoop->regBlocks = unionSets (theLoop->regBlocks,
-                                         lp->regBlocks, THROW_BOTH);
+                                         lp->regBlocks, THROW_DEST);
          lp->merged = 1;
        }
     }
@@ -1158,6 +1177,7 @@ 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 */