forked from OSchip/llvm-project
47 lines
1.6 KiB
C++
47 lines
1.6 KiB
C++
//===- BarrierNoopPass.cpp - A barrier pass for the pass manager ----------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// NOTE: DO NOT USE THIS IF AVOIDABLE
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//
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// This pass is a nonce pass intended to allow manipulation of the implicitly
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// nesting pass manager. For example, it can be used to cause a CGSCC pass
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// manager to be closed prior to running a new collection of function passes.
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//
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// FIXME: This is a huge HACK. This should be removed when the pass manager's
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// nesting is made explicit instead of implicit.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Pass.h"
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#include "llvm/Transforms/IPO.h"
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using namespace llvm;
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namespace {
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/// A nonce module pass used to place a barrier in a pass manager.
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///
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/// There is no mechanism for ending a CGSCC pass manager once one is started.
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/// This prevents extension points from having clear deterministic ordering
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/// when they are phrased as non-module passes.
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class BarrierNoop : public ModulePass {
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public:
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static char ID; // Pass identification.
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BarrierNoop() : ModulePass(ID) {
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initializeBarrierNoopPass(*PassRegistry::getPassRegistry());
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}
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bool runOnModule(Module &M) override { return false; }
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};
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}
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ModulePass *llvm::createBarrierNoopPass() { return new BarrierNoop(); }
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char BarrierNoop::ID = 0;
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INITIALIZE_PASS(BarrierNoop, "barrier", "A No-Op Barrier Pass",
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false, false)
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