[Mlir-commits] [mlir] [mlir][acc] Add utilities for converting acc.loop to scf (PR #172953)

[Razvan Lupusoru]

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@@ -0,0 +1,313 @@
+//===- OpenACCUtilsLoop.cpp - OpenACC Loop Utilities ----------------------===//
+//
+// 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 contains utility functions for converting OpenACC loops to SCF.
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/OpenACC/OpenACCUtilsLoop.h"
+
+#include "mlir/Dialect/Arith/IR/Arith.h"
+#include "mlir/Dialect/Arith/Utils/Utils.h"
+#include "mlir/Dialect/OpenACC/OpenACC.h"
+#include "mlir/Dialect/SCF/IR/SCF.h"
+#include "mlir/Dialect/SCF/Utils/Utils.h"
+#include "mlir/IR/IRMapping.h"
+
+using namespace mlir;
+
+namespace {
+
+/// Calculate trip count for a loop: (ub - lb + step) / step
+/// If inclusiveUpperbound is false, subtracts 1 from ub first.
+static Value calculateTripCount(OpBuilder &b, Location loc, Value lb, Value ub,
+                                Value step, bool inclusiveUpperbound) {
+  Type type = b.getIndexType();
+
+  // Convert original loop arguments to index type
+  lb = getValueOrCreateCastToIndexLike(b, loc, type, lb);
+  ub = getValueOrCreateCastToIndexLike(b, loc, type, ub);
+  step = getValueOrCreateCastToIndexLike(b, loc, type, step);
+
+  if (!inclusiveUpperbound) {
+    Value one = arith::ConstantIndexOp::create(b, loc, 1);
+    ub = b.createOrFold<arith::SubIOp>(loc, ub, one);
+  }
+
+  Value sub = b.createOrFold<arith::SubIOp>(loc, ub, lb);
+  Value add = b.createOrFold<arith::AddIOp>(loc, sub, step);
+  return b.createOrFold<arith::DivSIOp>(loc, add, step);
+}
+
+/// Get exclusive upper bound from acc.loop (add 1 if inclusive).
+static Value getExclusiveUpperBound(acc::LoopOp loopOp, size_t ivPos,
+                                    OpBuilder &b) {
+  bool isInclusive = false;
+  if (loopOp.getInclusiveUpperbound().has_value())
+    isInclusive = loopOp.getInclusiveUpperboundAttr().asArrayRef()[ivPos];
+
+  Value origUB = loopOp.getUpperbound()[ivPos];
+  if (isInclusive) {
+    Location loc = origUB.getLoc();
+    Value one;
+    Type ubType = origUB.getType();
+    if (ubType.isIndex())
+      one = arith::ConstantIndexOp::create(b, loc, 1);
+    else
+      one = arith::ConstantIntOp::create(b, loc, ubType, 1);
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razvanlupusoru wrote:

Great idea! Done!

https://github.com/llvm/llvm-project/pull/172953