[Mlir-commits] [mlir] [mlir][bufferization] Add best-fit algorithm to static memory planner (PR #207403)

[Matthias Springer]

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@@ -0,0 +1,109 @@
+//===- StaticMemoryPlanning.cpp - Memory planning algorithms --------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/Bufferization/Transforms/StaticMemoryPlanning.h"
+#include "llvm/Support/MathExtras.h"
+#include <numeric>
+
+using namespace mlir::bufferization;
+
+/// Align an offset to the specified alignment.
+static int64_t alignOffset(int64_t offset, int64_t alignment) {
+  return llvm::alignTo(offset, alignment);
+}
+
+llvm::SmallVector<int64_t> mlir::bufferization::trivialMemoryPlanner(
+    int64_t arenaAlignment, llvm::ArrayRef<MemoryPlannerAlloc> allocs) {
+  llvm::SmallVector<int64_t> offsets;
+  int64_t currentOffset = 0;
+
+  for (const auto &alloc : allocs) {
+    currentOffset = alignOffset(currentOffset, alloc.alignment);
+    assert((arenaAlignment + currentOffset) % alloc.alignment == 0 &&
+           "invalid alignment");
+    offsets.push_back(currentOffset);
+    currentOffset += alloc.sizeInBytes;
+  }
+
+  return offsets;
+}
+
+llvm::SmallVector<int64_t> mlir::bufferization::bestFitMemoryPlanner(
+    int64_t arenaAlignment, llvm::ArrayRef<MemoryPlannerAlloc> allocs) {
+  struct Placement {
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matthias-springer wrote:

Can you add a small comment here? How come we don't need `timeBegin` here?

https://github.com/llvm/llvm-project/pull/207403