1894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===-- llvm/CodeGen/LiveVariables.h - Live Variable Analysis ---*- C++ -*-===// 2894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 3894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// The LLVM Compiler Infrastructure 4894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 5894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// This file is distributed under the University of Illinois Open Source 6894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// License. See LICENSE.TXT for details. 7894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 8894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===----------------------------------------------------------------------===// 9894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 10894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// This file implements the LiveVariables analysis pass. For each machine 11894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// instruction in the function, this pass calculates the set of registers that 12894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// are immediately dead after the instruction (i.e., the instruction calculates 13894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// the value, but it is never used) and the set of registers that are used by 14894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// the instruction, but are never used after the instruction (i.e., they are 15894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// killed). 16894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 17894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// This class computes live variables using a sparse implementation based on 18894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// the machine code SSA form. This class computes live variable information for 19894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// each virtual and _register allocatable_ physical register in a function. It 20894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// uses the dominance properties of SSA form to efficiently compute live 21894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// variables for virtual registers, and assumes that physical registers are only 22894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// live within a single basic block (allowing it to do a single local analysis 23894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// to resolve physical register lifetimes in each basic block). If a physical 24894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// register is not register allocatable, it is not tracked. This is useful for 25894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// things like the stack pointer and condition codes. 26894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman// 27894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman//===----------------------------------------------------------------------===// 28894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 29894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#ifndef LLVM_CODEGEN_LIVEVARIABLES_H 30894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#define LLVM_CODEGEN_LIVEVARIABLES_H 31894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 32894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include "llvm/CodeGen/MachineBasicBlock.h" 33894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include "llvm/CodeGen/MachineFunctionPass.h" 34894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include "llvm/CodeGen/MachineInstr.h" 3519bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/Target/TargetRegisterInfo.h" 36894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include "llvm/ADT/BitVector.h" 37894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include "llvm/ADT/DenseMap.h" 3819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman#include "llvm/ADT/IndexedMap.h" 39894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include "llvm/ADT/SmallSet.h" 40894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include "llvm/ADT/SmallVector.h" 41894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#include "llvm/ADT/SparseBitVector.h" 42894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 43894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumannamespace llvm { 44894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 45894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanclass MachineRegisterInfo; 46894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanclass TargetRegisterInfo; 47894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 48894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanclass LiveVariables : public MachineFunctionPass { 49894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanpublic: 50894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman static char ID; // Pass identification, replacement for typeid 5119bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman LiveVariables() : MachineFunctionPass(ID) { 5219bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman initializeLiveVariablesPass(*PassRegistry::getPassRegistry()); 5319bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman } 54894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 55894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// VarInfo - This represents the regions where a virtual register is live in 56894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// the program. We represent this with three different pieces of 57894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// information: the set of blocks in which the instruction is live 58894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// throughout, the set of blocks in which the instruction is actually used, 59894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// and the set of non-phi instructions that are the last users of the value. 60894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// 61894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// In the common case where a value is defined and killed in the same block, 62894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// There is one killing instruction, and AliveBlocks is empty. 63894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// 64894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// Otherwise, the value is live out of the block. If the value is live 65894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// throughout any blocks, these blocks are listed in AliveBlocks. Blocks 66894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// where the liveness range ends are not included in AliveBlocks, instead 67894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// being captured by the Kills set. In these blocks, the value is live into 68894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// the block (unless the value is defined and killed in the same block) and 69894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// lives until the specified instruction. Note that there cannot ever be a 70894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// value whose Kills set contains two instructions from the same basic block. 71894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// 72894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// PHI nodes complicate things a bit. If a PHI node is the last user of a 73894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// value in one of its predecessor blocks, it is not listed in the kills set, 74894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// but does include the predecessor block in the AliveBlocks set (unless that 75894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// block also defines the value). This leads to the (perfectly sensical) 76894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// situation where a value is defined in a block, and the last use is a phi 77894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// node in the successor. In this case, AliveBlocks is empty (the value is 78894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// not live across any blocks) and Kills is empty (phi nodes are not 79894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// included). This is sensical because the value must be live to the end of 80894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// the block, but is not live in any successor blocks. 81894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman struct VarInfo { 82894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// AliveBlocks - Set of blocks in which this value is alive completely 83894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// through. This is a bit set which uses the basic block number as an 84894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// index. 85894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// 86894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman SparseBitVector<> AliveBlocks; 87894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 88894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// NumUses - Number of uses of this register across the entire function. 89894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// 90894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman unsigned NumUses; 91894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 92894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// Kills - List of MachineInstruction's which are the last use of this 93894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// virtual register (kill it) in their basic block. 94894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// 95894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman std::vector<MachineInstr*> Kills; 96894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 97894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman VarInfo() : NumUses(0) {} 98894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 99894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// removeKill - Delete a kill corresponding to the specified 100894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// machine instruction. Returns true if there was a kill 101894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// corresponding to this instruction, false otherwise. 102894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool removeKill(MachineInstr *MI) { 103894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman std::vector<MachineInstr*>::iterator 104894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman I = std::find(Kills.begin(), Kills.end(), MI); 105894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman if (I == Kills.end()) 106894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return false; 107894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman Kills.erase(I); 108894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return true; 109894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 110894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 111894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// findKill - Find a kill instruction in MBB. Return NULL if none is found. 112894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineInstr *findKill(const MachineBasicBlock *MBB) const; 113894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 114894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// isLiveIn - Is Reg live in to MBB? This means that Reg is live through 115894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// MBB, or it is killed in MBB. If Reg is only used by PHI instructions in 116894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// MBB, it is not considered live in. 117894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool isLiveIn(const MachineBasicBlock &MBB, 118894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman unsigned Reg, 119894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineRegisterInfo &MRI); 120894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 121894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void dump() const; 122894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman }; 123894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 124894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanprivate: 125894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// VirtRegInfo - This list is a mapping from virtual register number to 12619bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman /// variable information. 127894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// 12819bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman IndexedMap<VarInfo, VirtReg2IndexFunctor> VirtRegInfo; 129894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 130894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// PHIJoins - list of virtual registers that are PHI joins. These registers 131894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// may have multiple definitions, and they require special handling when 132894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// building live intervals. 133894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman SparseBitVector<> PHIJoins; 134894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 135894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// ReservedRegisters - This vector keeps track of which registers 136894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// are reserved register which are not allocatable by the target machine. 137894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// We can not track liveness for values that are in this set. 138894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// 139894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman BitVector ReservedRegisters; 140894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 141894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanprivate: // Intermediate data structures 142894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineFunction *MF; 143894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 144894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineRegisterInfo* MRI; 145894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 146894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman const TargetRegisterInfo *TRI; 147894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 148894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // PhysRegInfo - Keep track of which instruction was the last def of a 149894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // physical register. This is a purely local property, because all physical 150894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // register references are presumed dead across basic blocks. 151894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineInstr **PhysRegDef; 152894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 153894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // PhysRegInfo - Keep track of which instruction was the last use of a 154894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // physical register. This is a purely local property, because all physical 155894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // register references are presumed dead across basic blocks. 156894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineInstr **PhysRegUse; 157894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 158894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman SmallVector<unsigned, 4> *PHIVarInfo; 159894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 160894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // DistanceMap - Keep track the distance of a MI from the start of the 161894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // current basic block. 162894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman DenseMap<MachineInstr*, unsigned> DistanceMap; 163894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 164894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// HandlePhysRegKill - Add kills of Reg and its sub-registers to the 165894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// uses. Pay special attention to the sub-register uses which may come below 166894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// the last use of the whole register. 167894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool HandlePhysRegKill(unsigned Reg, MachineInstr *MI); 168894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 169894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void HandlePhysRegUse(unsigned Reg, MachineInstr *MI); 170894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void HandlePhysRegDef(unsigned Reg, MachineInstr *MI, 171894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman SmallVector<unsigned, 4> &Defs); 172894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void UpdatePhysRegDefs(MachineInstr *MI, SmallVector<unsigned, 4> &Defs); 173894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 174894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// FindLastRefOrPartRef - Return the last reference or partial reference of 175894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// the specified register. 176894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineInstr *FindLastRefOrPartRef(unsigned Reg); 177894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 178894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// FindLastPartialDef - Return the last partial def of the specified 179894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// register. Also returns the sub-registers that're defined by the 180894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// instruction. 181894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineInstr *FindLastPartialDef(unsigned Reg, 182894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman SmallSet<unsigned,4> &PartDefRegs); 183894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 184894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// analyzePHINodes - Gather information about the PHI nodes in here. In 185894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// particular, we want to map the variable information of a virtual 186894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// register which is used in a PHI node. We map that to the BB the vreg 187894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// is coming from. 188894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void analyzePHINodes(const MachineFunction& Fn); 189894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Baumanpublic: 190894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 191894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman virtual bool runOnMachineFunction(MachineFunction &MF); 192894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 193894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// RegisterDefIsDead - Return true if the specified instruction defines the 194894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// specified register, but that definition is dead. 195894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool RegisterDefIsDead(MachineInstr *MI, unsigned Reg) const; 196894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 197894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman //===--------------------------------------------------------------------===// 198894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman // API to update live variable information 199894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 200894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// replaceKillInstruction - Update register kill info by replacing a kill 201894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// instruction with a new one. 202894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void replaceKillInstruction(unsigned Reg, MachineInstr *OldMI, 203894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineInstr *NewMI); 204894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 205894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// addVirtualRegisterKilled - Add information about the fact that the 206894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// specified register is killed after being used by the specified 207894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// instruction. If AddIfNotFound is true, add a implicit operand if it's 208894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// not found. 209894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void addVirtualRegisterKilled(unsigned IncomingReg, MachineInstr *MI, 210894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool AddIfNotFound = false) { 211894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman if (MI->addRegisterKilled(IncomingReg, TRI, AddIfNotFound)) 212894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman getVarInfo(IncomingReg).Kills.push_back(MI); 213894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 214894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 215894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// removeVirtualRegisterKilled - Remove the specified kill of the virtual 216894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// register from the live variable information. Returns true if the 217894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// variable was marked as killed by the specified instruction, 218894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// false otherwise. 219894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool removeVirtualRegisterKilled(unsigned reg, MachineInstr *MI) { 220894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman if (!getVarInfo(reg).removeKill(MI)) 221894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return false; 222894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 223894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool Removed = false; 224894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 225894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineOperand &MO = MI->getOperand(i); 226894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman if (MO.isReg() && MO.isKill() && MO.getReg() == reg) { 227894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MO.setIsKill(false); 228894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman Removed = true; 229894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman break; 230894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 231894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 232894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 233894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman assert(Removed && "Register is not used by this instruction!"); 23419bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (void)Removed; 235894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return true; 236894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 237894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 238894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// removeVirtualRegistersKilled - Remove all killed info for the specified 239894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// instruction. 240894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void removeVirtualRegistersKilled(MachineInstr *MI); 241894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 242894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// addVirtualRegisterDead - Add information about the fact that the specified 243894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// register is dead after being used by the specified instruction. If 244894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// AddIfNotFound is true, add a implicit operand if it's not found. 245894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void addVirtualRegisterDead(unsigned IncomingReg, MachineInstr *MI, 246894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool AddIfNotFound = false) { 247894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman if (MI->addRegisterDead(IncomingReg, TRI, AddIfNotFound)) 248894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman getVarInfo(IncomingReg).Kills.push_back(MI); 249894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 250894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 251894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// removeVirtualRegisterDead - Remove the specified kill of the virtual 252894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// register from the live variable information. Returns true if the 253894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// variable was marked dead at the specified instruction, false 254894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// otherwise. 255894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool removeVirtualRegisterDead(unsigned reg, MachineInstr *MI) { 256894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman if (!getVarInfo(reg).removeKill(MI)) 257894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return false; 258894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 259894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool Removed = false; 260894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 261894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineOperand &MO = MI->getOperand(i); 262894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman if (MO.isReg() && MO.isDef() && MO.getReg() == reg) { 263894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MO.setIsDead(false); 264894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman Removed = true; 265894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman break; 266894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 267894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 268894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman assert(Removed && "Register is not defined by this instruction!"); 26919bac1e08be200c31efd26f0f5fd144c9b3eefd3John Bauman (void)Removed; 270894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return true; 271894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 272894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 273894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void getAnalysisUsage(AnalysisUsage &AU) const; 274894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 275894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman virtual void releaseMemory() { 276894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman VirtRegInfo.clear(); 277894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 278894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 279894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// getVarInfo - Return the VarInfo structure for the specified VIRTUAL 280894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// register. 281894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman VarInfo &getVarInfo(unsigned RegIdx); 282894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 283894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void MarkVirtRegAliveInBlock(VarInfo& VRInfo, MachineBasicBlock* DefBlock, 284894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineBasicBlock *BB); 285894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void MarkVirtRegAliveInBlock(VarInfo& VRInfo, MachineBasicBlock* DefBlock, 286894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineBasicBlock *BB, 287894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman std::vector<MachineBasicBlock*> &WorkList); 288894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void HandleVirtRegDef(unsigned reg, MachineInstr *MI); 289894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void HandleVirtRegUse(unsigned reg, MachineBasicBlock *MBB, 290894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineInstr *MI); 291894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 292894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool isLiveIn(unsigned Reg, const MachineBasicBlock &MBB) { 293894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman return getVarInfo(Reg).isLiveIn(MBB, Reg, *MRI); 294894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman } 295894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 296894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// isLiveOut - Determine if Reg is live out from MBB, when not considering 297894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// PHI nodes. This means that Reg is either killed by a successor block or 298894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// passed through one. 299894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool isLiveOut(unsigned Reg, const MachineBasicBlock &MBB); 300894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 301894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// addNewBlock - Add a new basic block BB between DomBB and SuccBB. All 302894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// variables that are live out of DomBB and live into SuccBB will be marked 303894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// as passing live through BB. This method assumes that the machine code is 304894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// still in SSA form. 305894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void addNewBlock(MachineBasicBlock *BB, 306894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineBasicBlock *DomBB, 307894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman MachineBasicBlock *SuccBB); 308894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 309894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// isPHIJoin - Return true if Reg is a phi join register. 310894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman bool isPHIJoin(unsigned Reg) { return PHIJoins.test(Reg); } 311894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 312894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman /// setPHIJoin - Mark Reg as a phi join register. 313894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman void setPHIJoin(unsigned Reg) { PHIJoins.set(Reg); } 314894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman}; 315894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 316894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman} // End llvm namespace 317894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman 318894018228b0e0bdbd7aa7e8f47d4a9458789ca82John Bauman#endif 319