[mlir][scf] Modify the return logic of generateLoopNestUsingForOp (NFC)

[linuxlonelyeagle]

When loops is empty, avoid executing yieldTiledValuesFn and Add a test which all tile sizes are set to zero.

[llvmbot]

@llvm/pr-subscribers-mlir-linalg

@llvm/pr-subscribers-mlir-scf

Author: lonely eagle (linuxlonelyeagle)

Changes

When loops is empty, avoid executing yieldTiledValuesFn.

---

Full diff: https://github.com/llvm/llvm-project/pull/159394.diff

1 Files Affected:

• (modified) mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp (+2-3)

diff --git a/mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp b/mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp
index 834c02126fa53..f24310ecd7beb 100644
--- a/mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp
+++ b/mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp
@@ -455,6 +455,8 @@ static LogicalResult generateLoopNestUsingForOp(
     rewriter.setInsertionPointToEnd(loop.getBody());
     destinationTensors = loop.getRegionIterArgs();
   }
+  if (loops.empty())
+    return success();
 
   SmallVector<Value> tiledResults;
   SmallVector<SmallVector<OpFoldResult>> resultOffsets, resultSizes;
@@ -463,9 +465,6 @@ static LogicalResult generateLoopNestUsingForOp(
     return rewriter.notifyMatchFailure(
         loc, "failed to generate inner tile loop body");
   }
-  if (loops.empty())
-    return success();
-
   assert(tiledResults.size() == destinationTensors.size() &&
          "Number of results of body should be equal to number of iter args");
 

[llvmbot]

@llvm/pr-subscribers-mlir

Author: lonely eagle (linuxlonelyeagle)

Changes

When loops is empty, avoid executing yieldTiledValuesFn.

---

Full diff: https://github.com/llvm/llvm-project/pull/159394.diff

1 Files Affected:

• (modified) mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp (+2-3)

diff --git a/mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp b/mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp
index 834c02126fa53..f24310ecd7beb 100644
--- a/mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp
+++ b/mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp
@@ -455,6 +455,8 @@ static LogicalResult generateLoopNestUsingForOp(
     rewriter.setInsertionPointToEnd(loop.getBody());
     destinationTensors = loop.getRegionIterArgs();
   }
+  if (loops.empty())
+    return success();
 
   SmallVector<Value> tiledResults;
   SmallVector<SmallVector<OpFoldResult>> resultOffsets, resultSizes;
@@ -463,9 +465,6 @@ static LogicalResult generateLoopNestUsingForOp(
     return rewriter.notifyMatchFailure(
         loc, "failed to generate inner tile loop body");
   }
-  if (loops.empty())
-    return success();
-
   assert(tiledResults.size() == destinationTensors.size() &&
          "Number of results of body should be equal to number of iter args");
 

[MaheshRavishankar]

Thanks! As far as I remember the logic though, since we previously check that the tile sizes are not all 0 (which leads to no loops), this shouldnt happen here. But no harm.

Could you add a test for this?

[linuxlonelyeagle]

@MaheshRavishankar ping for review.Thank you.

[linuxlonelyeagle]

@MaheshRavishankar Thank you. I remember you answered my question a year or two ago.

[llvm-ci]

LLVM Buildbot has detected a new failure on builder ppc64le-mlir-rhel-clang running on ppc64le-mlir-rhel-test while building mlir at step 6 "test-build-check-mlir-build-only-check-mlir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/129/builds/30041

Here is the relevant piece of the build log for the reference

Step 6 (test-build-check-mlir-build-only-check-mlir) failure: 1200 seconds without output running [b'ninja', b'check-mlir'], attempting to kill
...
PASS: MLIR-Unit :: IR/./MLIRIRTests/100/129 (3496 of 3507)
PASS: MLIR-Unit :: IR/./MLIRIRTests/0/129 (3497 of 3507)
PASS: MLIR-Unit :: IR/./MLIRIRTests/39/129 (3498 of 3507)
PASS: MLIR-Unit :: IR/./MLIRIRTests/38/129 (3499 of 3507)
PASS: MLIR-Unit :: Interfaces/./MLIRInterfacesTests/11/22 (3500 of 3507)
PASS: MLIR-Unit :: Interfaces/./MLIRInterfacesTests/13/22 (3501 of 3507)
PASS: MLIR-Unit :: Interfaces/./MLIRInterfacesTests/12/22 (3502 of 3507)
PASS: MLIR-Unit :: Pass/./MLIRPassTests/10/13 (3503 of 3507)
PASS: MLIR :: mlir-tblgen/llvm-intrinsics.td (3504 of 3507)
PASS: MLIR :: mlir-reduce/dce-test.mlir (3505 of 3507)
command timed out: 1200 seconds without output running [b'ninja', b'check-mlir'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=1906.447722