/* Worker function to compute the idom */
static bool computeImmediateDominator(CompilationUnit *cUnit, BasicBlock *bb) {
GrowableList *blockList = &cUnit->blockList;
BitVector *tempBlockV = cUnit->tempBlockV;
BitVectorIterator bvIterator;
BasicBlock *iDom;
if (bb == cUnit->entryBlock) return false;
dvmCopyBitVector(tempBlockV, bb->dominators);
dvmClearBit(tempBlockV, bb->id);
dvmBitVectorIteratorInit(tempBlockV, &bvIterator);
/* Should not see any dead block */
assert(dvmCountSetBits(tempBlockV) != 0);
if (dvmCountSetBits(tempBlockV) == 1) {
iDom = (BasicBlock *) dvmGrowableListGetElement(
blockList, dvmBitVectorIteratorNext(&bvIterator));
bb->iDom = iDom;
} else {
int iDomIdx = dvmBitVectorIteratorNext(&bvIterator);
assert(iDomIdx != -1);
while (true) {
int nextDom = dvmBitVectorIteratorNext(&bvIterator);
if (nextDom == -1) break;
BasicBlock *nextDomBB = (BasicBlock *)
dvmGrowableListGetElement(blockList, nextDom);
/* iDom dominates nextDom - set new iDom */
if (dvmIsBitSet(nextDomBB->dominators, iDomIdx)) {
iDomIdx = nextDom;
}
}
iDom = (BasicBlock *) dvmGrowableListGetElement(blockList, iDomIdx);
/* Set the immediate dominator block for bb */
bb->iDom = iDom;
}
/* Add bb to the iDominated set of the immediate dominator block */
dvmCompilerSetBit(iDom->iDominated, bb->id);
return true;
}
/*
* Remove a register pair from the LIVE set.
*/
static inline void KILLW(BitVector* workBits, u4 regIndex)
{
dvmClearBit(workBits, regIndex);
dvmClearBit(workBits, regIndex+1);
}
