Files
llvm-project/llvm/lib/CodeGen/MachinePostDominators.cpp
T
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00

80 lines
2.4 KiB
C++

//===- MachinePostDominators.cpp -Machine Post Dominator Calculation ------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements simple dominator construction algorithms for finding
// post dominators on machine functions.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachinePostDominators.h"
#include "llvm/InitializePasses.h"
using namespace llvm;
namespace llvm {
template class DominatorTreeBase<MachineBasicBlock, true>; // PostDomTreeBase
extern bool VerifyMachineDomInfo;
} // namespace llvm
char MachinePostDominatorTree::ID = 0;
//declare initializeMachinePostDominatorTreePass
INITIALIZE_PASS(MachinePostDominatorTree, "machinepostdomtree",
"MachinePostDominator Tree Construction", true, true)
MachinePostDominatorTree::MachinePostDominatorTree()
: MachineFunctionPass(ID), PDT(nullptr) {
initializeMachinePostDominatorTreePass(*PassRegistry::getPassRegistry());
}
FunctionPass *MachinePostDominatorTree::createMachinePostDominatorTreePass() {
return new MachinePostDominatorTree();
}
bool MachinePostDominatorTree::runOnMachineFunction(MachineFunction &F) {
PDT = std::make_unique<PostDomTreeT>();
PDT->recalculate(F);
return false;
}
void MachinePostDominatorTree::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
MachineBasicBlock *MachinePostDominatorTree::findNearestCommonDominator(
ArrayRef<MachineBasicBlock *> Blocks) const {
assert(!Blocks.empty());
MachineBasicBlock *NCD = Blocks.front();
for (MachineBasicBlock *BB : Blocks.drop_front()) {
NCD = PDT->findNearestCommonDominator(NCD, BB);
// Stop when the root is reached.
if (PDT->isVirtualRoot(PDT->getNode(NCD)))
return nullptr;
}
return NCD;
}
void MachinePostDominatorTree::verifyAnalysis() const {
if (PDT && VerifyMachineDomInfo)
if (!PDT->verify(PostDomTreeT::VerificationLevel::Basic)) {
errs() << "MachinePostDominatorTree verification failed\n";
abort();
}
}
void MachinePostDominatorTree::print(llvm::raw_ostream &OS,
const Module *M) const {
PDT->print(OS);
}