1 //===- LiveStacks.h - Live Stack Slot Analysis ------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file implements the live stack slot analysis pass. It is analogous to
10 // live interval analysis except it's analyzing liveness of stack slots rather
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CODEGEN_LIVESTACKS_H
16 #define LLVM_CODEGEN_LIVESTACKS_H
18 #include "llvm/CodeGen/LiveInterval.h"
19 #include "llvm/CodeGen/MachineFunctionPass.h"
20 #include "llvm/Pass.h"
23 #include <unordered_map>
27 class TargetRegisterClass;
28 class TargetRegisterInfo;
30 class LiveStacks : public MachineFunctionPass {
31 const TargetRegisterInfo *TRI;
33 /// Special pool allocator for VNInfo's (LiveInterval val#).
35 VNInfo::Allocator VNInfoAllocator;
37 /// S2IMap - Stack slot indices to live interval mapping.
38 using SS2IntervalMap = std::unordered_map<int, LiveInterval>;
39 SS2IntervalMap S2IMap;
41 /// S2RCMap - Stack slot indices to register class mapping.
42 std::map<int, const TargetRegisterClass *> S2RCMap;
45 static char ID; // Pass identification, replacement for typeid
47 LiveStacks() : MachineFunctionPass(ID) {
48 initializeLiveStacksPass(*PassRegistry::getPassRegistry());
51 using iterator = SS2IntervalMap::iterator;
52 using const_iterator = SS2IntervalMap::const_iterator;
54 const_iterator begin() const { return S2IMap.begin(); }
55 const_iterator end() const { return S2IMap.end(); }
56 iterator begin() { return S2IMap.begin(); }
57 iterator end() { return S2IMap.end(); }
59 unsigned getNumIntervals() const { return (unsigned)S2IMap.size(); }
61 LiveInterval &getOrCreateInterval(int Slot, const TargetRegisterClass *RC);
63 LiveInterval &getInterval(int Slot) {
64 assert(Slot >= 0 && "Spill slot indice must be >= 0");
65 SS2IntervalMap::iterator I = S2IMap.find(Slot);
66 assert(I != S2IMap.end() && "Interval does not exist for stack slot");
70 const LiveInterval &getInterval(int Slot) const {
71 assert(Slot >= 0 && "Spill slot indice must be >= 0");
72 SS2IntervalMap::const_iterator I = S2IMap.find(Slot);
73 assert(I != S2IMap.end() && "Interval does not exist for stack slot");
77 bool hasInterval(int Slot) const { return S2IMap.count(Slot); }
79 const TargetRegisterClass *getIntervalRegClass(int Slot) const {
80 assert(Slot >= 0 && "Spill slot indice must be >= 0");
81 std::map<int, const TargetRegisterClass *>::const_iterator I =
83 assert(I != S2RCMap.end() &&
84 "Register class info does not exist for stack slot");
88 VNInfo::Allocator &getVNInfoAllocator() { return VNInfoAllocator; }
90 void getAnalysisUsage(AnalysisUsage &AU) const override;
91 void releaseMemory() override;
93 /// runOnMachineFunction - pass entry point
94 bool runOnMachineFunction(MachineFunction &) override;
96 /// print - Implement the dump method.
97 void print(raw_ostream &O, const Module * = nullptr) const override;
100 } // end namespace llvm