[PATCH] D77083: [MLIR] Add pattern rewriter util to erase block; add affine.if pattern to remove dead else blocks

[Uday Bondhugula via Phabricator via llvm-commits]

bondhugula marked an inline comment as done.
bondhugula added inline comments.


================
Comment at: mlir/lib/IR/PatternMatch.cpp:94
+  for (auto &op : llvm::make_early_inc_range(*block)) {
+    assert(op.use_empty() && "expected 'op' to have no uses");
+    notifyOperationRemoved(&op);
----------------
rriddle wrote:
> bondhugula wrote:
> > rriddle wrote:
> > > This seems wrong, any non-trivially empty block will likely fail this check. Did you want to iterate the block in reverse?
> > Sorry, I didn't understand - what's a non-trivially empty block? AFAICT, the block is either empty of ops or it isn't. 
> If you have something like:
> 
> ^bb:
> %cst = constant 0 : i64
> foo.yield %cst : i64
> 
> This will assert when trying to erase the block. Why should we assert that all ops have no uses?
It looks like I was looking at the wrong line / code context - fixed, thanks. 


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https://reviews.llvm.org/D77083