1 //===-------- EdgeBundles.h - Bundles of CFG edges --------------*- c++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // The EdgeBundles analysis forms equivalence classes of CFG edges such that all
11 // edges leaving a machine basic block are in the same bundle, and all edges
12 // leaving a basic block are in the same bundle.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_CODEGEN_EDGEBUNDLES_H
17 #define LLVM_CODEGEN_EDGEBUNDLES_H
18 
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/IntEqClasses.h"
21 #include "llvm/ADT/Twine.h"
22 #include "llvm/CodeGen/MachineFunctionPass.h"
23 
24 namespace llvm {
25 
26 class EdgeBundles : public MachineFunctionPass {
27   const MachineFunction *MF;
28 
29   /// EC - Each edge bundle is an equivalence class. The keys are:
30   ///   2*BB->getNumber()   -> Ingoing bundle.
31   ///   2*BB->getNumber()+1 -> Outgoing bundle.
32   IntEqClasses EC;
33 
34   /// Blocks - Map each bundle to a list of basic block numbers.
35   SmallVector<SmallVector<unsigned, 8>, 4> Blocks;
36 
37 public:
38   static char ID;
EdgeBundles()39   EdgeBundles() : MachineFunctionPass(ID) {}
40 
41   /// getBundle - Return the ingoing (Out = false) or outgoing (Out = true)
42   /// bundle number for basic block #N
getBundle(unsigned N,bool Out)43   unsigned getBundle(unsigned N, bool Out) const { return EC[2 * N + Out]; }
44 
45   /// getNumBundles - Return the total number of bundles in the CFG.
getNumBundles()46   unsigned getNumBundles() const { return EC.getNumClasses(); }
47 
48   /// getBlocks - Return an array of blocks that are connected to Bundle.
getBlocks(unsigned Bundle)49   ArrayRef<unsigned> getBlocks(unsigned Bundle) const { return Blocks[Bundle]; }
50 
51   /// getMachineFunction - Return the last machine function computed.
getMachineFunction()52   const MachineFunction *getMachineFunction() const { return MF; }
53 
54   /// view - Visualize the annotated bipartite CFG with Graphviz.
55   void view() const;
56 
57 private:
58   bool runOnMachineFunction(MachineFunction&) override;
59   void getAnalysisUsage(AnalysisUsage&) const override;
60 };
61 
62 } // end namespace llvm
63 
64 #endif
65