/*-----------------------------------------------------------------*/
void
replaceLabel (eBBlock * ebp, symbol * fromLbl, symbol * toLbl)
{
iCode *ic;
if (!ebp)
return;
for (ic = ebp->sch; ic; ic = ic->next)
{
switch (ic->op)
{
case GOTO:
if (isSymbolEqual (IC_LABEL (ic), fromLbl))
IC_LABEL (ic) = toLbl;
break;
case IFX:
if (IC_TRUE (ic) && isSymbolEqual (IC_TRUE (ic), fromLbl))
IC_TRUE (ic) = toLbl;
else if (isSymbolEqual (IC_FALSE (ic), fromLbl))
IC_FALSE (ic) = toLbl;
break;
}
}
return;
}
static void visit (set **visited, iCode *ic, const int key)
{
symbol *lbl;
while (ic && !isinSet (*visited, ic) && bitVectBitValue (ic->rlive, key))
{
addSet (visited, ic);
switch (ic->op)
{
case GOTO:
ic = hTabItemWithKey (labelDef, (IC_LABEL (ic))->key);
break;
case RETURN:
ic = hTabItemWithKey (labelDef, returnLabel->key);
break;
case JUMPTABLE:
for (lbl = setFirstItem (IC_JTLABELS (ic)); lbl; lbl = setNextItem (IC_JTLABELS (ic)))
visit (visited, hTabItemWithKey (labelDef, lbl->key), key);
break;
case IFX:
visit (visited, hTabItemWithKey (labelDef, (IC_TRUE(ic) ? IC_TRUE (ic) : IC_FALSE (ic))->key), key);
ic = ic->next;
break;
default:
ic = ic->next;
if (!POINTER_SET (ic) && IC_RESULT (ic) && IS_SYMOP (IC_RESULT (ic)) && OP_SYMBOL_CONST (IC_RESULT (ic))->key == key)
{
addSet (visited, ic);
return;
}
}
}
}
/*-----------------------------------------------------------------*/
ebbIndex *
iCodeBreakDown (iCode * ic)
{
eBBlock **ebbs = NULL;
iCode *loop = ic;
ebbIndex *ebbi;
ebbi = Safe_alloc (sizeof (ebbIndex));
ebbi->count = 0;
ebbi->dfOrder = NULL; /* no depth first order information yet */
/* allocate for the first entry */
ebbs = Safe_alloc (sizeof (eBBlock *));
ebbi->bbOrder = ebbs;
while (loop)
{
/* convert 2 block */
eBBlock *ebb = iCode2eBBlock (loop);
loop = ebb->ech->next;
ebb->ech->next = NULL; /* mark the end of this chain */
if (loop)
loop->prev = NULL;
ebb->bbnum = ebbi->count; /* save this block number */
/* put it in the array */
ebbs[(ebbi->count)++] = ebb;
/* allocate for the next one. Remember to clear the new */
/* pointer at the end, that was created by realloc. */
ebbs = Safe_realloc (ebbs, (ebbi->count + 1) * sizeof (eBBlock *));
ebbi->bbOrder = ebbs;
ebbs[ebbi->count] = 0;
/* if this one ends in a goto or a conditional */
/* branch then check if the block it is going */
/* to already exists, if yes then this could */
/* be a loop, add a preheader to the block it */
/* goes to if it does not already have one */
if (ebbs[(ebbi->count) - 1]->ech &&
(ebbs[(ebbi->count) - 1]->ech->op == GOTO ||
ebbs[(ebbi->count) - 1]->ech->op == IFX))
{
symbol *label;
eBBlock *destBlock;
if (ebbs[(ebbi->count) - 1]->ech->op == GOTO)
label = IC_LABEL (ebbs[(ebbi->count) - 1]->ech);
else if (!(label = IC_TRUE (ebbs[(ebbi->count) - 1]->ech)))
label = IC_FALSE (ebbs[(ebbi->count) - 1]->ech);
if ((destBlock = eBBWithEntryLabel (ebbi, label)) &&
destBlock->preHeader == NULL &&
otherPathsPresent (ebbs, destBlock))
{
symbol *preHeaderLabel = newiTempLoopHeaderLabel (1);
int i, j;
eBBlock *pBlock;
/* go thru all block replacing the entryLabel with new label */
/* till we reach the block , then we insert a new ebblock */
for (i = 0; i < (ebbi->count); i++)
{
if (ebbs[i] == destBlock)
break;
replaceLabel (ebbs[i], label, preHeaderLabel);
}
(ebbi->count)++;
/* if we have stopped at the block , allocate for an extra one */
ebbs = Safe_realloc (ebbs, (ebbi->count + 1) * sizeof (eBBlock *));
ebbi->bbOrder = ebbs;
ebbs[ebbi->count] = 0;
/* then move the block down one count */
pBlock = ebbs[j = i];
for (i += 1; i < (ebbi->count); i++)
{
eBBlock *xBlock;
xBlock = ebbs[i];
ebbs[i] = pBlock;
ebbs[i]->bbnum = i;
pBlock = xBlock;
}
destBlock->preHeader = ebbs[j] = neweBBlock ();
ebbs[j]->bbnum = j;
ebbs[j]->entryLabel = preHeaderLabel;
ebbs[j]->sch = ebbs[j]->ech = newiCodeLabelGoto (LABEL, preHeaderLabel);
ebbs[j]->sch->filename = destBlock->sch->filename;
ebbs[j]->sch->lineno = destBlock->sch->lineno;
}
}
}
/* mark the end */
ebbs[ebbi->count] = NULL;
return ebbi;
}
