From 15c572c97427d730638c321bcec63593ce536d2b Mon Sep 17 00:00:00 2001
From: erwei-xilinx <erweiw@xilinx.com>
Date: Thu, 29 Aug 2024 18:23:04 -0700
Subject: [PATCH] Packet flow new error message for `aie.packet_rule` op
 (#1738)

---
 .../AIE/Transforms/AIECreatePathFindFlows.cpp | 13 ++++++++
 test/create-packet-flows/badpacket_flow.mlir  | 31 +++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 test/create-packet-flows/badpacket_flow.mlir

diff --git a/lib/Dialect/AIE/Transforms/AIECreatePathFindFlows.cpp b/lib/Dialect/AIE/Transforms/AIECreatePathFindFlows.cpp
index 9c17853fa1..e369cb56b1 100644
--- a/lib/Dialect/AIE/Transforms/AIECreatePathFindFlows.cpp
+++ b/lib/Dialect/AIE/Transforms/AIECreatePathFindFlows.cpp
@@ -746,6 +746,19 @@ void AIEPathfinderPass::runOnPacketFlow(DeviceOp device, OpBuilder &builder) {
         packetrules = slaveRules[slave];
 
       Block &rules = packetrules.getRules().front();
+
+      // Verify ID mapping against all other rules of the same slave.
+      for (auto rule : rules.getOps<PacketRuleOp>()) {
+        auto verifyMask = rule.maskInt();
+        auto verifyValue = rule.valueInt();
+        if ((group.front().second & verifyMask) == verifyValue) {
+          rule->emitOpError("can lead to false packet id match for id ")
+              << ID << ", which is not supposed to pass through this port.";
+          rule->emitRemark("Please consider changing all uses of packet id ")
+              << ID << " to avoid deadlock.";
+        }
+      }
+
       builder.setInsertionPoint(rules.getTerminator());
       builder.create<PacketRuleOp>(builder.getUnknownLoc(), mask, ID, amsel);
     }
diff --git a/test/create-packet-flows/badpacket_flow.mlir b/test/create-packet-flows/badpacket_flow.mlir
new file mode 100644
index 0000000000..9d43484fd5
--- /dev/null
+++ b/test/create-packet-flows/badpacket_flow.mlir
@@ -0,0 +1,31 @@
+//===- badpacket_flow.mlir -------------------------------------*- MLIR -*-===//
+//
+// This file is licensed 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
+//
+// (c) Copyright 2024 Advanced Micro Devices, Inc.
+//
+//===----------------------------------------------------------------------===//
+
+// RUN: aie-opt --aie-create-pathfinder-flows %s 2>&1 | FileCheck %s
+// CHECK: error{{.*}} 'aie.rule' op can lead to false packet id match for id 28, which is not supposed to pass through this port
+// CHECK: remark: Please consider changing all uses of packet id 28 to avoid deadlock.
+
+aie.device(npu1_1col) {
+  %03 = aie.tile(0, 3)
+  %02 = aie.tile(0, 2)
+  %00 = aie.tile(0, 0)
+  aie.packet_flow(28) {
+    aie.packet_source<%00, DMA : 0>
+    aie.packet_dest<%02, Ctrl : 0>
+  }
+  aie.packet_flow(29) {
+    aie.packet_source<%00, DMA : 0>
+    aie.packet_dest<%03, Ctrl : 0>
+  }
+  aie.packet_flow(26) {
+    aie.packet_source<%00, DMA : 0>
+    aie.packet_dest<%03, DMA : 0>
+  }
+}