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| 1 | +//===- AIEAssignCoreLinkFiles.cpp -------------------------------*- C++ -*-===// |
| 2 | +// |
| 3 | +// This file is licensed under the Apache License v2.0 with LLVM Exceptions. |
| 4 | +// See https://llvm.org/LICENSE.txt for license information. |
| 5 | +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | +// |
| 7 | +// (c) Copyright 2026 Advanced Micro Devices Inc. |
| 8 | +// |
| 9 | +//===----------------------------------------------------------------------===// |
| 10 | +// |
| 11 | +// This pass infers the per-core set of external object files required for |
| 12 | +// linking by tracing call edges from each core to func.func declarations that |
| 13 | +// carry a "link_with" attribute. |
| 14 | +// |
| 15 | +// After the pass runs, every CoreOp that needs external files will have a |
| 16 | +// "link_files" StrArrayAttr containing the (de-duplicated) list of .o paths. |
| 17 | +// |
| 18 | +// Core-level "link_with" (deprecated) is also migrated: its value is added to |
| 19 | +// the set and the attribute is removed from the CoreOp. |
| 20 | +// |
| 21 | +//===----------------------------------------------------------------------===// |
| 22 | + |
| 23 | +#include "aie/Dialect/AIE/IR/AIEDialect.h" |
| 24 | +#define GEN_PASS_DEF_AIEASSIGNCORELINKFILES |
| 25 | +#include "aie/Dialect/AIE/Transforms/AIEPasses.h" |
| 26 | + |
| 27 | +#include "mlir/Dialect/Func/IR/FuncOps.h" |
| 28 | +#include "mlir/IR/Builders.h" |
| 29 | +#include "mlir/Pass/Pass.h" |
| 30 | + |
| 31 | +#include "llvm/ADT/DenseSet.h" |
| 32 | +#include "llvm/ADT/SetVector.h" |
| 33 | + |
| 34 | +#define DEBUG_TYPE "aie-assign-core-link-files" |
| 35 | + |
| 36 | +using namespace mlir; |
| 37 | +using namespace xilinx; |
| 38 | +using namespace xilinx::AIE; |
| 39 | + |
| 40 | +struct AIEAssignCoreLinkFilesPass |
| 41 | + : xilinx::AIE::impl::AIEAssignCoreLinkFilesBase< |
| 42 | + AIEAssignCoreLinkFilesPass> { |
| 43 | + void runOnOperation() override { |
| 44 | + DeviceOp device = getOperation(); |
| 45 | + // Builder is used only for attribute construction; no ops are inserted. |
| 46 | + Builder builder(device.getContext()); |
| 47 | + |
| 48 | + // Build a map from func name to the object file(s) it requires, sourced |
| 49 | + // from the "link_with" string attribute on func.func declarations. |
| 50 | + // StringRefs are views into MLIRContext-owned storage and remain valid |
| 51 | + // for the entire pass run. |
| 52 | + DenseMap<StringRef, SmallVector<StringRef, 2>> funcToObjs; |
| 53 | + for (auto funcOp : device.getOps<mlir::func::FuncOp>()) { |
| 54 | + if (auto attr = funcOp->getAttrOfType<mlir::StringAttr>("link_with")) { |
| 55 | + funcToObjs[funcOp.getName()].push_back(attr.getValue()); |
| 56 | + } |
| 57 | + } |
| 58 | + |
| 59 | + // Tracks which func.func symbols are directly called from at least one |
| 60 | + // core; used to warn about link_with-bearing functions that are never |
| 61 | + // called and whose object files would otherwise be silently omitted. |
| 62 | + llvm::DenseSet<StringRef> usedFuncs; |
| 63 | + |
| 64 | + // Only direct func.call edges are traced. func.call_indirect ops and |
| 65 | + // calls through intermediate wrapper functions are not followed. To |
| 66 | + // handle transitive dependencies, attach link_with directly to every |
| 67 | + // func.func declaration that a core calls, even thin wrappers. |
| 68 | + // TODO: extend to transitive call resolution. |
| 69 | + device.walk([&](CoreOp core) { |
| 70 | + // De-duplicate while preserving insertion order. |
| 71 | + llvm::SetVector<StringRef> needed; |
| 72 | + |
| 73 | + // Migrate deprecated core-level attr: warn, consume it, and add to set. |
| 74 | + if (auto lw = core.getLinkWith()) { |
| 75 | + core.emitWarning( |
| 76 | + "link_with on aie.core is deprecated; attach link_with to " |
| 77 | + "the func.func declaration instead"); |
| 78 | + needed.insert(lw.value()); |
| 79 | + core->removeAttr("link_with"); |
| 80 | + } |
| 81 | + |
| 82 | + // Single walk over the core body: collect required object files and |
| 83 | + // record called symbols (for the unused-func warning below). |
| 84 | + core.walk([&](Operation *op) { |
| 85 | + if (auto call = dyn_cast<mlir::func::CallOp>(op)) { |
| 86 | + usedFuncs.insert(call.getCallee()); |
| 87 | + auto it = funcToObjs.find(call.getCallee()); |
| 88 | + if (it != funcToObjs.end()) |
| 89 | + for (StringRef obj : it->second) |
| 90 | + needed.insert(obj); |
| 91 | + } else if (auto indCall = dyn_cast<mlir::func::CallIndirectOp>(op)) { |
| 92 | + indCall.emitWarning( |
| 93 | + "indirect call in core body — link_with attributes on " |
| 94 | + "indirectly-called functions are not automatically resolved; " |
| 95 | + "add a direct func.call to the required func.func declaration " |
| 96 | + "so that aie-assign-core-link-files can trace the dependency"); |
| 97 | + } |
| 98 | + }); |
| 99 | + |
| 100 | + if (!needed.empty()) { |
| 101 | + // builder is used only for attribute construction; its insertion |
| 102 | + // point is irrelevant and no ops are inserted. |
| 103 | + core.setLinkFilesAttr(builder.getStrArrayAttr(needed.getArrayRef())); |
| 104 | + } |
| 105 | + }); |
| 106 | + |
| 107 | + // Warn about funcs with link_with that are never called from any core. |
| 108 | + for (auto &[funcName, objs] : funcToObjs) { |
| 109 | + if (!usedFuncs.count(funcName)) { |
| 110 | + if (auto funcOp = device.lookupSymbol<mlir::func::FuncOp>(funcName)) |
| 111 | + funcOp.emitWarning() |
| 112 | + << "func '" << funcName |
| 113 | + << "' has link_with but is never called from any core; " |
| 114 | + "its .o file will not be linked"; |
| 115 | + } |
| 116 | + } |
| 117 | + } |
| 118 | +}; |
| 119 | + |
| 120 | +std::unique_ptr<OperationPass<DeviceOp>> |
| 121 | +AIE::createAIEAssignCoreLinkFilesPass() { |
| 122 | + return std::make_unique<AIEAssignCoreLinkFilesPass>(); |
| 123 | +} |
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