int iCodeSeq = 0;
hTab *liveRanges = NULL;
hTab *iCodehTab = NULL;
+hTab *iCodeSeqhTab = NULL;
/*-----------------------------------------------------------------*/
/* sequenceiCode - creates a sequence number for the iCode & add */
ic->seq = ++iCodeSeq;
ic->depth = ebbs[i]->depth;
hTabAddItem (&iCodehTab, ic->key, ic);
+ hTabAddItem (&iCodeSeqhTab, ic->seq, ic);
}
ebbs[i]->lSeq = iCodeSeq;
}
(OP_LIVETO (op) && OP_LIVETO (op) < ic->seq))
{
int torange = ic->seq;
+
+ /* if this is a SEND then the toRange should be extended
+ to the call */
+ if (ic->op == SEND) {
+ iCode *lic ;
+ for (lic = ic->next ; lic ; lic = lic->next) {
+ if (lic->op == CALL || lic->op == PCALL) break;
+ }
+ /* found it : mark */
+ if (lic) torange = lic->prev->seq;
+ }
/* if this is the last use then if this block belongs
to a loop & some definition comes into the loop
then extend the live range to the end of the loop */
if (ebp->partOfLoop
- /* && hasIncomingDefs (ebp->partOfLoop, op)*/ )
+ && hasIncomingDefs (ebp->partOfLoop, op))
{
torange = findLoopEndSeq (ebp->partOfLoop);
}
+
op = operandFromOperand (op);
setToRange (op, torange, FALSE);
}
void
rlivePoint (eBBlock ** ebbs, int count)
{
- int i;
-
- /* for all blocks do */
- for (i = 0; i < count; i++) {
- iCode *ic;
-
- /* for all instruction in the block do */
- for (ic = ebbs[i]->sch; ic; ic = ic->next) {
- symbol *lrange;
- int k;
-
- ic->rlive = newBitVect (operandKey);
- /* for all symbols in the liverange table */
- for (lrange = hTabFirstItem (liveRanges, &k); lrange;
- lrange = hTabNextItem (liveRanges, &k)) {
-
- /* if it is live then add the lrange to ic->rlive */
- if (lrange->liveFrom <= ic->seq &&
- lrange->liveTo >= ic->seq) {
- lrange->isLiveFcall |= (ic->op == CALL || ic->op == PCALL || ic->op == SEND);
- ic->rlive = bitVectSetBit (ic->rlive, lrange->key);
- }
- }
- /* overlapping live ranges should be eliminated */
- if (ASSIGN_ITEMP_TO_ITEMP (ic)) {
-
- if (SPIL_LOC(IC_RIGHT(ic)) == SPIL_LOC(IC_RESULT(ic)) && /* left & right share the same spil location */
- OP_SYMBOL(IC_RESULT(ic))->isreqv && /* left of assign is a register requivalent */
- !OP_SYMBOL(IC_RIGHT(ic))->isreqv && /* right side is not */
- OP_SYMBOL(IC_RIGHT(ic))->liveTo > ic->key && /* right side live beyond this point */
- bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) > 1 ) { /* left has multiple definitions */
- SPIL_LOC(IC_RIGHT(ic)) = NULL; /* then cannot share */
- }
- }
+ int i;
+
+ /* for all blocks do */
+ for (i = 0; i < count; i++) {
+ iCode *ic;
+
+ /* for all instruction in the block do */
+ for (ic = ebbs[i]->sch; ic; ic = ic->next) {
+ symbol *lrange;
+ int k;
+
+ ic->rlive = newBitVect (operandKey);
+ /* for all symbols in the liverange table */
+ for (lrange = hTabFirstItem (liveRanges, &k); lrange;
+ lrange = hTabNextItem (liveRanges, &k)) {
+
+ /* if it is live then add the lrange to ic->rlive */
+ if (lrange->liveFrom <= ic->seq &&
+ lrange->liveTo >= ic->seq) {
+ lrange->isLiveFcall |= (ic->op == CALL || ic->op == PCALL || ic->op == SEND);
+ ic->rlive = bitVectSetBit (ic->rlive, lrange->key);
}
+ }
+ /* overlapping live ranges should be eliminated */
+ if (ASSIGN_ITEMP_TO_ITEMP (ic)) {
+ if (SPIL_LOC(IC_RIGHT(ic)) == SPIL_LOC(IC_RESULT(ic)) && /* left & right share the same spil location */
+ OP_SYMBOL(IC_RESULT(ic))->isreqv && /* left of assign is a register requivalent */
+ !OP_SYMBOL(IC_RIGHT(ic))->isreqv && /* right side is not */
+ OP_SYMBOL(IC_RIGHT(ic))->liveTo > ic->key && /* right side live beyond this point */
+ bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) > 1 ) { /* left has multiple definitions */
+ SPIL_LOC(IC_RIGHT(ic)) = NULL; /* then cannot share */
+ }
+ }
}
+ }
}
+/*-----------------------------------------------------------------*/
+/* computeClash - find out which live ranges collide with others */
+/*-----------------------------------------------------------------*/
+static void computeClash ()
+{
+ hTab *lRangeCopy = newHashTable(hTabMaxKey(liveRanges));
+ void *item;
+ symbol *outer, *inner;
+ int key, key1;
+
+ /* have to make a copy of the liveRanges hashTable :: UGHH .*/
+ for (item = hTabFirstItem(liveRanges,&key); item ;
+ item = hTabNextItem(liveRanges,&key)) {
+ hTabAddItem(&lRangeCopy,key,item);
+ }
+
+ /* outerloop : for each liverange do */
+ for (outer = hTabFirstItem(liveRanges,&key); outer ;
+ outer = hTabNextItem(liveRanges,&key)) {
+
+ /* if the liveFrom & To are the same then skip,
+ could happen for unused return values from functions */
+ if (outer->liveFrom == outer->liveTo) continue;
+
+ /* innerloop : for the inner loop we can start from the
+ item after the outer loop */
+ inner = hTabFirstItemWK (lRangeCopy,outer->key);
+ inner = hTabNextItem (lRangeCopy,&key1 );
+ for (; inner ; inner = hTabNextItem( lRangeCopy ,&key1)) {
+
+ if (inner->liveFrom == inner->liveTo) continue;
+ if (inner->liveTo < outer->liveFrom) continue;
+ if (inner->liveFrom > outer->liveTo) continue;
+
+ /* if one of them are being defined where the other
+ one end , then no overlap (i.e. they can goto same registers */
+ if (inner->liveFrom == outer->liveTo ||
+ outer->liveFrom == inner->liveTo) continue;
+
+ /* so they overlap : set both their clashes */
+ inner->clashes = bitVectSetBit(inner->clashes,outer->key);
+ outer->clashes = bitVectSetBit(outer->clashes,inner->key);
+
+ /* check if they share the same spillocation */
+ if (SYM_SPIL_LOC(inner) && SYM_SPIL_LOC(outer) &&
+ SYM_SPIL_LOC(inner) == SYM_SPIL_LOC(outer)) {
+ if (inner->reqv && !outer->reqv) SYM_SPIL_LOC(outer)=NULL;
+ else if (outer->reqv && !inner->reqv) SYM_SPIL_LOC(inner)=NULL;
+ else if (inner->used > outer->used) SYM_SPIL_LOC(outer)=NULL;
+ else SYM_SPIL_LOC(inner)=NULL;
+ }
+
+ }
+ }
+}
/*-----------------------------------------------------------------*/
/* computeLiveRanges - computes the live ranges for variables */
iCodeSeq = 0;
setToNull ((void **) &iCodehTab);
iCodehTab = newHashTable (iCodeKey);
+ setToNull ((void **) &iCodeSeqhTab);
+ iCodeSeqhTab = newHashTable (iCodeKey);
sequenceiCode (ebbs, count);
/* call routine to mark the from & to live ranges for
/* mark the ranges live for each point */
rlivePoint (ebbs, count);
+
+ /* compute which overlaps with what */
+ computeClash();
}
projects / fw / sdcc / blobdiff