diff options
| -rw-r--r-- | include/llvm/InitializePasses.h | 1 | ||||
| -rw-r--r-- | include/llvm/Transforms/IPO.h | 5 | ||||
| -rw-r--r-- | lib/Transforms/IPO/BarrierNoopPass.cpp | 47 | ||||
| -rw-r--r-- | lib/Transforms/IPO/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | lib/Transforms/IPO/PassManagerBuilder.cpp | 8 |
5 files changed, 62 insertions, 0 deletions
diff --git a/include/llvm/InitializePasses.h b/include/llvm/InitializePasses.h index 263b84a08e..3fda779ae9 100644 --- a/include/llvm/InitializePasses.h +++ b/include/llvm/InitializePasses.h @@ -66,6 +66,7 @@ void initializeAliasDebuggerPass(PassRegistry&); void initializeAliasSetPrinterPass(PassRegistry&); void initializeAlwaysInlinerPass(PassRegistry&); void initializeArgPromotionPass(PassRegistry&); +void initializeBarrierNoopPass(PassRegistry&); void initializeBasicAliasAnalysisPass(PassRegistry&); void initializeBasicCallGraphPass(PassRegistry&); void initializeBlockExtractorPassPass(PassRegistry&); diff --git a/include/llvm/Transforms/IPO.h b/include/llvm/Transforms/IPO.h index 962cb63758..08d3bbd941 100644 --- a/include/llvm/Transforms/IPO.h +++ b/include/llvm/Transforms/IPO.h @@ -198,6 +198,11 @@ ModulePass *createPartialInliningPass(); // ModulePass *createMetaRenamerPass(); +//===----------------------------------------------------------------------===// +/// createBarrierNoopPass - This pass is purely a module pass barrier in a pass +/// manager. +ModulePass *createBarrierNoopPass(); + } // End llvm namespace #endif diff --git a/lib/Transforms/IPO/BarrierNoopPass.cpp b/lib/Transforms/IPO/BarrierNoopPass.cpp new file mode 100644 index 0000000000..2e32240621 --- /dev/null +++ b/lib/Transforms/IPO/BarrierNoopPass.cpp @@ -0,0 +1,47 @@ +//===- BarrierNoopPass.cpp - A barrier pass for the pass manager ----------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// NOTE: DO NOT USE THIS IF AVOIDABLE +// +// This pass is a nonce pass intended to allow manipulation of the implicitly +// nesting pass manager. For example, it can be used to cause a CGSCC pass +// manager to be closed prior to running a new collection of function passes. +// +// FIXME: This is a huge HACK. This should be removed when the pass manager's +// nesting is made explicit instead of implicit. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Pass.h" +#include "llvm/Transforms/IPO.h" +using namespace llvm; + +namespace { +/// \brief A nonce module pass used to place a barrier in a pass manager. +/// +/// There is no mechanism for ending a CGSCC pass manager once one is started. +/// This prevents extension points from having clear deterministic ordering +/// when they are phrased as non-module passes. +class BarrierNoop : public ModulePass { +public: + static char ID; // Pass identification. + + BarrierNoop() : ModulePass(ID) { + initializeBarrierNoopPass(*PassRegistry::getPassRegistry()); + } + + bool runOnModule(Module &M) { return false; } +}; +} + +ModulePass *llvm::createBarrierNoopPass() { return new BarrierNoop(); } + +char BarrierNoop::ID = 0; +INITIALIZE_PASS(BarrierNoop, "barrier", "A No-Op Barrier Pass", + false, false) diff --git a/lib/Transforms/IPO/CMakeLists.txt b/lib/Transforms/IPO/CMakeLists.txt index 3f6b1de614..90c1c33e6d 100644 --- a/lib/Transforms/IPO/CMakeLists.txt +++ b/lib/Transforms/IPO/CMakeLists.txt @@ -1,5 +1,6 @@ add_llvm_library(LLVMipo ArgumentPromotion.cpp + BarrierNoopPass.cpp ConstantMerge.cpp DeadArgumentElimination.cpp ExtractGV.cpp diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp index 97698caa51..1d8f1e531a 100644 --- a/lib/Transforms/IPO/PassManagerBuilder.cpp +++ b/lib/Transforms/IPO/PassManagerBuilder.cpp @@ -119,6 +119,14 @@ void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) { MPM.add(Inliner); Inliner = 0; } + + // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC + // pass manager, but we don't want to add extensions into that pass manager. + // To prevent this we must insert a no-op module pass to reset the pass + // manager to get the same behavior as EP_OptimizerLast in non-O0 builds. + if (!GlobalExtensions->empty() || !Extensions.empty()) + MPM.add(createBarrierNoopPass()); + addExtensionsToPM(EP_EnabledOnOptLevel0, MPM); return; } |