[DAGCombiner] Expand combining of FP logical ops to sign-setting FP ops
[llvm-core.git] / include / llvm / Analysis / IntervalPartition.h
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1 //===- IntervalPartition.h - Interval partition Calculation -----*- 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 // This file contains the declaration of the IntervalPartition class, which
11 // calculates and represents the interval partition of a function, or a
12 // preexisting interval partition.
14 // In this way, the interval partition may be used to reduce a flow graph down
15 // to its degenerate single node interval partition (unless it is irreducible).
17 // TODO: The IntervalPartition class should take a bool parameter that tells
18 // whether it should add the "tails" of an interval to an interval itself or if
19 // they should be represented as distinct intervals.
21 //===----------------------------------------------------------------------===//
23 #ifndef LLVM_ANALYSIS_INTERVALPARTITION_H
24 #define LLVM_ANALYSIS_INTERVALPARTITION_H
26 #include "llvm/Pass.h"
27 #include <map>
28 #include <vector>
30 namespace llvm {
32 class BasicBlock;
33 class Interval;
35 //===----------------------------------------------------------------------===//
37 // IntervalPartition - This class builds and holds an "interval partition" for
38 // a function. This partition divides the control flow graph into a set of
39 // maximal intervals, as defined with the properties above. Intuitively, an
40 // interval is a (possibly nonexistent) loop with a "tail" of non-looping
41 // nodes following it.
43 class IntervalPartition : public FunctionPass {
44 using IntervalMapTy = std::map<BasicBlock *, Interval *>;
45 IntervalMapTy IntervalMap;
47 using IntervalListTy = std::vector<Interval *>;
48 Interval *RootInterval = nullptr;
49 std::vector<Interval *> Intervals;
51 public:
52 static char ID; // Pass identification, replacement for typeid
54 IntervalPartition() : FunctionPass(ID) {
55 initializeIntervalPartitionPass(*PassRegistry::getPassRegistry());
58 // run - Calculate the interval partition for this function
59 bool runOnFunction(Function &F) override;
61 // IntervalPartition ctor - Build a reduced interval partition from an
62 // existing interval graph. This takes an additional boolean parameter to
63 // distinguish it from a copy constructor. Always pass in false for now.
64 IntervalPartition(IntervalPartition &I, bool);
66 // print - Show contents in human readable format...
67 void print(raw_ostream &O, const Module* = nullptr) const override;
69 // getRootInterval() - Return the root interval that contains the starting
70 // block of the function.
71 inline Interval *getRootInterval() { return RootInterval; }
73 // isDegeneratePartition() - Returns true if the interval partition contains
74 // a single interval, and thus cannot be simplified anymore.
75 bool isDegeneratePartition() { return Intervals.size() == 1; }
77 // TODO: isIrreducible - look for triangle graph.
79 // getBlockInterval - Return the interval that a basic block exists in.
80 inline Interval *getBlockInterval(BasicBlock *BB) {
81 IntervalMapTy::iterator I = IntervalMap.find(BB);
82 return I != IntervalMap.end() ? I->second : nullptr;
85 // getAnalysisUsage - Implement the Pass API
86 void getAnalysisUsage(AnalysisUsage &AU) const override {
87 AU.setPreservesAll();
90 // Interface to Intervals vector...
91 const std::vector<Interval*> &getIntervals() const { return Intervals; }
93 // releaseMemory - Reset state back to before function was analyzed
94 void releaseMemory() override;
96 private:
97 // addIntervalToPartition - Add an interval to the internal list of intervals,
98 // and then add mappings from all of the basic blocks in the interval to the
99 // interval itself (in the IntervalMap).
100 void addIntervalToPartition(Interval *I);
102 // updatePredecessors - Interval generation only sets the successor fields of
103 // the interval data structures. After interval generation is complete,
104 // run through all of the intervals and propagate successor info as
105 // predecessor info.
106 void updatePredecessors(Interval *Int);
109 } // end namespace llvm
111 #endif // LLVM_ANALYSIS_INTERVALPARTITION_H