[Mlir-commits] [mlir] [mlir] Add transformation to wrap scf::while in zero-trip-check (PR #81050)

[Jerry Wu]

================
@@ -0,0 +1,58 @@
+//===- TestWrapInZeroTripCheck.cpp -- Passes to test SCF zero-trip-check --===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the passes to test wrap-in-zero-trip-check transforms on
+// SCF loop ops.
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+#include "mlir/Dialect/SCF/IR/SCF.h"
+#include "mlir/Dialect/SCF/Transforms/Transforms.h"
+#include "mlir/IR/PatternMatch.h"
+#include "mlir/Pass/Pass.h"
+
+using namespace mlir;
+
+namespace {
+
+struct TestWrapWhileLoopInZeroTripCheck
+    : public PassWrapper<TestWrapWhileLoopInZeroTripCheck,
+                         OperationPass<func::FuncOp>> {
+  MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(TestWrapWhileLoopInZeroTripCheck)
+
+  StringRef getArgument() const final {
+    return "test-wrap-scf-while-loop-in-zero-trip-check";
+  }
+  StringRef getDescription() const final {
+    return "test scf::wrapWhileLoopInZeroTripCheck";
+  }
+
+  void runOnOperation() override {
+    func::FuncOp func = getOperation();
+    MLIRContext *context = &getContext();
+    IRRewriter rewriter(context);
+    func.walk([&](scf::WhileOp op) {
+      auto result = scf::wrapWhileLoopInZeroTripCheck(op, rewriter);
+      if (failed(result)) {
+        // Ignore not implemented failure in tests. The expected output should
+        // catch problems (e.g. transformation doesn't happen).
+      }
----------------
pzread wrote:

Done. Keep the comment to explain why it is okay to not check result

https://github.com/llvm/llvm-project/pull/81050