[Mlir-commits] [mlir] [mlir][scf] Uplift `scf.while` to `scf.for` (PR #76108)

[Mehdi Amini]

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@@ -0,0 +1,238 @@
+//===- UpliftWhileToFor.cpp - scf.while to scf.for loop uplifting ---------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Transforms SCF.WhileOp's into SCF.ForOp's.
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/SCF/Transforms/Passes.h"
+
+#include "mlir/Dialect/Arith/IR/Arith.h"
+#include "mlir/Dialect/SCF/IR/SCF.h"
+#include "mlir/Dialect/SCF/Transforms/Patterns.h"
+#include "mlir/IR/Dominance.h"
+#include "mlir/IR/PatternMatch.h"
+#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
+
+namespace mlir {
+#define GEN_PASS_DEF_TESTSCFUPLIFTWHILETOFOR
+#include "mlir/Dialect/SCF/Transforms/Passes.h.inc"
+} // namespace mlir
+
+using namespace mlir;
+
+namespace {
+struct UpliftWhileOp : public OpRewritePattern<scf::WhileOp> {
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joker-eph wrote:

It seems to me that we'd better decouple the transformation from the pattern.

That is: expose it as a C++ API `FailureOr<scf::ForOp> upliftWhileToForLoop(scf::WhileOp loop);` exposed in a public header, and have the client code decide their integration point (this could connect to the Transform dialect for example).

https://github.com/llvm/llvm-project/pull/76108