LLVM  9.0.0svn
FuncletLayout.cpp
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1 //===-- FuncletLayout.cpp - Contiguously lay out funclets -----------------===//
2 //
3 // Part of the LLVM Project, 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 //===----------------------------------------------------------------------===//
8 //
9 // This file implements basic block placement transformations which result in
10 // funclets being contiguous.
11 //
12 //===----------------------------------------------------------------------===//
13 #include "llvm/CodeGen/Analysis.h"
16 #include "llvm/CodeGen/Passes.h"
17 using namespace llvm;
18 
19 #define DEBUG_TYPE "funclet-layout"
20 
21 namespace {
22 class FuncletLayout : public MachineFunctionPass {
23 public:
24  static char ID; // Pass identification, replacement for typeid
25  FuncletLayout() : MachineFunctionPass(ID) {
27  }
28 
29  bool runOnMachineFunction(MachineFunction &F) override;
30  MachineFunctionProperties getRequiredProperties() const override {
33  }
34 };
35 }
36 
37 char FuncletLayout::ID = 0;
39 INITIALIZE_PASS(FuncletLayout, DEBUG_TYPE,
40  "Contiguously Lay Out Funclets", false, false)
41 
42 bool FuncletLayout::runOnMachineFunction(MachineFunction &F) {
43  // Even though this gets information from getEHScopeMembership(), this pass is
44  // only necessary for funclet-based EH personalities, in which these EH scopes
45  // are outlined at the end.
48  if (FuncletMembership.empty())
49  return false;
50 
51  F.sort([&](MachineBasicBlock &X, MachineBasicBlock &Y) {
52  auto FuncletX = FuncletMembership.find(&X);
53  auto FuncletY = FuncletMembership.find(&Y);
54  assert(FuncletX != FuncletMembership.end());
55  assert(FuncletY != FuncletMembership.end());
56  return FuncletX->second < FuncletY->second;
57  });
58 
59  // Conservatively assume we changed something.
60  return true;
61 }
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
This class represents lattice values for constants.
Definition: AllocatorList.h:23
char & FuncletLayoutID
This pass lays out funclets contiguously.
INITIALIZE_PASS(FuncletLayout, DEBUG_TYPE, "Contiguously Lay Out Funclets", false, false) bool FuncletLayout
F(f)
static GCMetadataPrinterRegistry::Add< OcamlGCMetadataPrinter > Y("ocaml", "ocaml 3.10-compatible collector")
MachineFunctionPass - This class adapts the FunctionPass interface to allow convenient creation of pa...
void initializeFuncletLayoutPass(PassRegistry &)
#define DEBUG_TYPE
DenseMap< const MachineBasicBlock *, int > getEHScopeMembership(const MachineFunction &MF)
Definition: Analysis.cpp:723
MachineFunctionProperties & set(Property P)
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Properties which a MachineFunction may have at a given point in time.