1 //===-------- EdgeBundles.h - Bundles of CFG edges --------------*- c++ -*-===//
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 // The EdgeBundles analysis forms equivalence classes of CFG edges such that all
10 // edges leaving a machine basic block are in the same bundle, and all edges
11 // leaving a basic block are in the same bundle.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CODEGEN_EDGEBUNDLES_H
16 #define LLVM_CODEGEN_EDGEBUNDLES_H
17 
18 #include "llvm/ADT/ArrayRef.h"
19 #include "llvm/ADT/IntEqClasses.h"
20 #include "llvm/ADT/Twine.h"
21 #include "llvm/CodeGen/MachineFunctionPass.h"
22 
23 namespace llvm {
24 
25 class EdgeBundles : public MachineFunctionPass {
26   const MachineFunction *MF;
27 
28   /// EC - Each edge bundle is an equivalence class. The keys are:
29   ///   2*BB->getNumber()   -> Ingoing bundle.
30   ///   2*BB->getNumber()+1 -> Outgoing bundle.
31   IntEqClasses EC;
32 
33   /// Blocks - Map each bundle to a list of basic block numbers.
34   SmallVector<SmallVector<unsigned, 8>, 4> Blocks;
35 
36 public:
37   static char ID;
38   EdgeBundles() : MachineFunctionPass(ID) {}
39 
40   /// getBundle - Return the ingoing (Out = false) or outgoing (Out = true)
41   /// bundle number for basic block #N
42   unsigned getBundle(unsigned N, bool Out) const { return EC[2 * N + Out]; }
43 
44   /// getNumBundles - Return the total number of bundles in the CFG.
45   unsigned getNumBundles() const { return EC.getNumClasses(); }
46 
47   /// getBlocks - Return an array of blocks that are connected to Bundle.
48   ArrayRef<unsigned> getBlocks(unsigned Bundle) const { return Blocks[Bundle]; }
49 
50   /// getMachineFunction - Return the last machine function computed.
51   const MachineFunction *getMachineFunction() const { return MF; }
52 
53   /// view - Visualize the annotated bipartite CFG with Graphviz.
54   void view() const;
55 
56 private:
57   bool runOnMachineFunction(MachineFunction&) override;
58   void getAnalysisUsage(AnalysisUsage&) const override;
59 };
60 
61 } // end namespace llvm
62 
63 #endif
64