[Mlir-commits] [mlir] [MLIR] Improve in-place folding to iterate until fixed-point (PR #160615)

[Eric Feng]

efric wrote:

@joker-eph 

Cherry picked this and tested on SDXL in IREE.

Some stats:

```
 124054 mlir-builder-try-to-fold     - Number of OpBuilder::tryFold loop total calls
      3 mlir-builder-try-to-fold     - Number of OpBuilder::tryFold loop max iterations
 124247 mlir-builder-try-to-fold     - Number of OpBuilder::tryFold loop total iterations
     86 mlir-builder-try-to-fold     - OpBuilder::tryFold total loop time (us)
```

So average number of iterations is roughly 1.

No calls to the one in `FoldUtils.cpp`.

No meaningful increase in total compilation time :smile:.

https://github.com/llvm/llvm-project/pull/160615