[Mlir-commits] [mlir] [mlir] reduce excessive verification in transform (PR #192653)

[Oleksandr Alex Zinenko]

https://github.com/ftynse updated https://github.com/llvm/llvm-project/pull/192653

>From 966ffea2f73b6728b5051e50002f9f1b6418dbd6 Mon Sep 17 00:00:00 2001
From: Alex Zinenko <git at ozinenko.com>
Date: Fri, 17 Apr 2026 15:31:31 +0200
Subject: [PATCH] [mlir] reduce excessive verification in transform

`mergeSymbolsInto` called by the transform interpreter for named
sequence management was calling a full verifier after renaming symbols.
The renaming could have potentially broken symbol table-related
invariants, but not really anything else. Only verify the symbol
table-related invariants intead.
---
 mlir/lib/Dialect/Transform/IR/Utils.cpp       | 12 ++++++++----
 mlir/test/Dialect/Transform/normal-forms.mlir |  9 ++++-----
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/mlir/lib/Dialect/Transform/IR/Utils.cpp b/mlir/lib/Dialect/Transform/IR/Utils.cpp
index 773eb138cdf62..4c2f0ab376231 100644
--- a/mlir/lib/Dialect/Transform/IR/Utils.cpp
+++ b/mlir/lib/Dialect/Transform/IR/Utils.cpp
@@ -168,11 +168,12 @@ transform::detail::mergeSymbolsInto(Operation *target,
     }
   }
 
-  // TODO: This duplicates pass infrastructure. We should split this pass into
-  //       several and let the pass infrastructure do the verification.
+  // We only modified symbols above, so there is no need to verify everything
+  // again, just the symbol table.
   for (auto *op : SmallVector<Operation *>{target, *other}) {
-    if (failed(mlir::verify(op)))
-      return op->emitError() << "failed to verify input op after renaming";
+    if (failed(mlir::detail::verifySymbolTable(op)))
+      return op->emitError()
+             << "failed to verify symbol table after symbol renaming";
   }
 
   // Step 2:
@@ -234,6 +235,9 @@ transform::detail::mergeSymbolsInto(Operation *target,
     }
   }
 
+  // Need full verification here because merging/inlining may have broken some
+  // nesting invariants that were not broken in the sources.
+  // TODO: implement and use InlinerDialectInterface to avoid this check.
   if (failed(mlir::verify(target)))
     return target->emitError()
            << "failed to verify target op after merging symbols";
diff --git a/mlir/test/Dialect/Transform/normal-forms.mlir b/mlir/test/Dialect/Transform/normal-forms.mlir
index 652f68a902a5b..9c5cce81c133d 100644
--- a/mlir/test/Dialect/Transform/normal-forms.mlir
+++ b/mlir/test/Dialect/Transform/normal-forms.mlir
@@ -139,17 +139,16 @@ transform.payload attributes {
 
 // We have surprisingly many invocations of the verifier here:
 //  1. after the initial parsing (reasonable)
-//  2. in transform::detail::mergeSymbolsInto (looks excessive)
-//  3. also in transform::detail::mergeSymbolsInto (has a TODO to be removed)
-//  4. after the transform interpreter pass (reasonable)
-//  5. before printing (generally reasonable, but would be nice to avoid if 
+//  2. also in transform::detail::mergeSymbolsInto (has a TODO to be removed)
+//  3. after the transform interpreter pass (reasonable)
+//  4. before printing (generally reasonable, but would be nice to avoid if
 //     the IR is known-verified after by the pass manager).
 // Notably this doesn't include an extra run from checkPayload, which is
 // what we intend to test here.
 
 // CHECK-LABEL: @verification_count
 // CHECK: transform.payload
-// CHECK-SAME: test.counting_normal_form_count = 5
+// CHECK-SAME: test.counting_normal_form_count = 4
 
 module @verification_count attributes {transform.with_named_sequence} {
   transform.payload attributes {