[Mlir-commits] [mlir] 587d6fc - [mlir] Recover the behavior of SliceAnaylsis for llvm-project at 6a8dde04a07 (#142076)

[llvmlistbot at llvm.org]

Author: Han-Chung Wang
Date: 2025-05-29T19:18:14-07:00
New Revision: 587d6fcbb685e3a57803110695a1996ac895d8b8

URL: https://github.com/llvm/llvm-project/commit/587d6fcbb685e3a57803110695a1996ac895d8b8
DIFF: https://github.com/llvm/llvm-project/commit/587d6fcbb685e3a57803110695a1996ac895d8b8.diff

LOG: [mlir] Recover the behavior of SliceAnaylsis for llvm-project at 6a8dde04a07 (#142076)

In
https://github.com/llvm/llvm-project/commit/6a8dde04a07287f837bbabeb93e23e47af366d3d,
it changes the method to return LogicalFailure, so callers can handle
the failure instead of crashing, if I read the intention correctly.
However, it changes the behavior of the implementation; it breaks
several integratino tests in downstream projects (e.g., IREE).

Before the change, processValue does not treat it as a failure if the
check below TODO has a false condition. However, with the new change, it
starts treating it as a failure.

The revision updates the final `else` branch (i.e., `llvm_unreachable`
line) to return a failure, and return success at the end; the behavior
is recovered.

```cpp
auto processValue = [&](Value value) {
  if (auto *definingOp = value.getDefiningOp()) {
    if (backwardSlice->count(definingOp) == 0)
      getBackwardSliceImpl(definingOp, backwardSlice, options);
  } else if (auto blockArg = dyn_cast<BlockArgument>(value)) {
    if (options.omitBlockArguments)
      return;

    Block *block = blockArg.getOwner();
    Operation *parentOp = block->getParentOp();
    // TODO: determine whether we want to recurse backward into the other
    // blocks of parentOp, which are not technically backward unless they flow
    // into us. For now, just bail.
    if (parentOp && backwardSlice->count(parentOp) == 0) {
      assert(parentOp->getNumRegions() == 1 &&
             llvm::hasSingleElement(parentOp->getRegion(0).getBlocks()));
      getBackwardSliceImpl(parentOp, backwardSlice, options);

    }
  } else {
    llvm_unreachable("No definingOp and not a block argument.");
  }
```

No additional tests are added, like the previous commit. This revision
is mostly a post-fix for
https://github.com/llvm/llvm-project/commit/6a8dde04a07287f837bbabeb93e23e47af366d3d

Co-authored-by: Ian Wood <ianwood2024 at u.northwestern.edu>

Signed-off-by: hanhanW <hanhan0912 at gmail.com>

Added: 
    

Modified: 
    mlir/lib/Analysis/SliceAnalysis.cpp

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Analysis/SliceAnalysis.cpp b/mlir/lib/Analysis/SliceAnalysis.cpp
index c4eda71c42f3e..4cdf47a405c01 100644
--- a/mlir/lib/Analysis/SliceAnalysis.cpp
+++ b/mlir/lib/Analysis/SliceAnalysis.cpp
@@ -111,8 +111,10 @@ static LogicalResult getBackwardSliceImpl(Operation *op,
           return getBackwardSliceImpl(parentOp, backwardSlice, options);
         }
       }
+    } else {
+      return failure();
     }
-    return failure();
+    return success();
   };
 
   bool succeeded = true;