Skip to content

[mlir][Affine][NFC] Amortize cost of block op index lookups #156027

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

[mlir][Affine][NFC] Amortize cost of block op index lookups #156027

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 16 additions & 4 deletions mlir/lib/Dialect/Affine/Analysis/Utils.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1442,16 +1442,28 @@ template LogicalResult
mlir::affine::boundCheckLoadOrStoreOp(AffineWriteOpInterface storeOp,
bool emitError);

static inline unsigned getIndexInBlock(
Operation *op,
llvm::DenseMap<Block *, llvm::DenseMap<Operation *, unsigned>> &cache) {
Block *block = op->getBlock();
auto &blockMap = cache[block];
if (blockMap.empty()) {
unsigned idx = 0;
for (Operation &it : *block)
blockMap[&it] = idx++;
}
return blockMap.lookup(op);
}

// Returns in 'positions' the Block positions of 'op' in each ancestor
// Block from the Block containing operation, stopping at 'limitBlock'.
static void findInstPosition(Operation *op, Block *limitBlock,
SmallVectorImpl<unsigned> *positions) {
llvm::DenseMap<Block *, llvm::DenseMap<Operation *, unsigned>> indexCache;

Block *block = op->getBlock();
while (block != limitBlock) {
// FIXME: This algorithm is unnecessarily O(n) and should be improved to not
// rely on linear scans.
int instPosInBlock = std::distance(block->begin(), op->getIterator());
positions->push_back(instPosInBlock);
positions->push_back(getIndexInBlock(op, indexCache));
op = block->getParentOp();
block = op->getBlock();
}
Expand Down