[mlir][Transforms][NFC] Dialect Conversion: Replace after legalizing constants

[matthias-springer]

When folding an op during a conversion, first try to legalize all generated constants, then replace the original operation. This is slightly more efficient because fewer rewrites must be rolled back in case a generated constant could not be legalized.

Note: This is in preparation of the One-Shot Dialect Conversion refactoring.

[llvmbot]

@llvm/pr-subscribers-mlir-core

Author: Matthias Springer (matthias-springer)

Changes

When folding an op during a conversion, first try to legalize all generated constants, then replace the original operation. This is slightly more efficient because fewer rewrites must be rolled back in case a generated constant could not be legalized.

Note: This is in preparation of the One-Shot Dialect Conversion refactoring.

---

Full diff: https://github.com/llvm/llvm-project/pull/134384.diff

1 Files Affected:

• (modified) mlir/lib/Transforms/Utils/DialectConversion.cpp (+3-3)

diff --git a/mlir/lib/Transforms/Utils/DialectConversion.cpp b/mlir/lib/Transforms/Utils/DialectConversion.cpp
index 444c505b64232..0b342a0e5d4bc 100644
--- a/mlir/lib/Transforms/Utils/DialectConversion.cpp
+++ b/mlir/lib/Transforms/Utils/DialectConversion.cpp
@@ -2109,9 +2109,6 @@ OperationLegalizer::legalizeWithFold(Operation *op,
   if (replacementValues.empty())
     return legalize(op, rewriter);
 
-  // Insert a replacement for 'op' with the folded replacement values.
-  rewriter.replaceOp(op, replacementValues);
-
   // Recursively legalize any new constant operations.
   for (unsigned i = curState.numRewrites, e = rewriterImpl.rewrites.size();
        i != e; ++i) {
@@ -2128,6 +2125,9 @@ OperationLegalizer::legalizeWithFold(Operation *op,
     }
   }
 
+  // Insert a replacement for 'op' with the folded replacement values.
+  rewriter.replaceOp(op, replacementValues);
+
   LLVM_DEBUG(logSuccess(rewriterImpl.logger, ""));
   return success();
 }

[llvmbot]

@llvm/pr-subscribers-mlir

Author: Matthias Springer (matthias-springer)

Changes

When folding an op during a conversion, first try to legalize all generated constants, then replace the original operation. This is slightly more efficient because fewer rewrites must be rolled back in case a generated constant could not be legalized.

Note: This is in preparation of the One-Shot Dialect Conversion refactoring.

---

Full diff: https://github.com/llvm/llvm-project/pull/134384.diff

1 Files Affected:

• (modified) mlir/lib/Transforms/Utils/DialectConversion.cpp (+3-3)

diff --git a/mlir/lib/Transforms/Utils/DialectConversion.cpp b/mlir/lib/Transforms/Utils/DialectConversion.cpp
index 444c505b64232..0b342a0e5d4bc 100644
--- a/mlir/lib/Transforms/Utils/DialectConversion.cpp
+++ b/mlir/lib/Transforms/Utils/DialectConversion.cpp
@@ -2109,9 +2109,6 @@ OperationLegalizer::legalizeWithFold(Operation *op,
   if (replacementValues.empty())
     return legalize(op, rewriter);
 
-  // Insert a replacement for 'op' with the folded replacement values.
-  rewriter.replaceOp(op, replacementValues);
-
   // Recursively legalize any new constant operations.
   for (unsigned i = curState.numRewrites, e = rewriterImpl.rewrites.size();
        i != e; ++i) {
@@ -2128,6 +2125,9 @@ OperationLegalizer::legalizeWithFold(Operation *op,
     }
   }
 
+  // Insert a replacement for 'op' with the folded replacement values.
+  rewriter.replaceOp(op, replacementValues);
+
   LLVM_DEBUG(logSuccess(rewriterImpl.logger, ""));
   return success();
 }

[zero9178]

LGTM!