| //===- SwiftErrorValueTracking.h - Track swifterror VReg vals --*- C++ -*--===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This implements a limited mem2reg-like analysis to promote uses of function |
| // arguments and allocas marked with swiftalloc from memory into virtual |
| // registers tracked by this class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef SWIFTERRORVALUETRACKING_H |
| #define SWIFTERRORVALUETRACKING_H |
| |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/CodeGen/Register.h" |
| #include "llvm/IR/BasicBlock.h" |
| #include "llvm/IR/DebugLoc.h" |
| #include <functional> |
| #include <type_traits> |
| #include <utility> |
| |
| |
| namespace llvm { |
| class Function; |
| class MachineBasicBlock; |
| class MachineFunction; |
| class MachineInstr; |
| class TargetInstrInfo; |
| class TargetLowering; |
| |
| class SwiftErrorValueTracking { |
| // Some useful objects to reduce the number of function arguments needed. |
| MachineFunction *MF; |
| const Function *Fn; |
| const TargetLowering *TLI; |
| const TargetInstrInfo *TII; |
| |
| /// A map from swifterror value in a basic block to the virtual register it is |
| /// currently represented by. |
| DenseMap<std::pair<const MachineBasicBlock *, const Value *>, Register> |
| VRegDefMap; |
| |
| /// A list of upward exposed vreg uses that need to be satisfied by either a |
| /// copy def or a phi node at the beginning of the basic block representing |
| /// the predecessor(s) swifterror value. |
| DenseMap<std::pair<const MachineBasicBlock *, const Value *>, Register> |
| VRegUpwardsUse; |
| |
| /// A map from instructions that define/use a swifterror value to the virtual |
| /// register that represents that def/use. |
| llvm::DenseMap<PointerIntPair<const Instruction *, 1, bool>, Register> |
| VRegDefUses; |
| |
| /// The swifterror argument of the current function. |
| const Value *SwiftErrorArg; |
| |
| using SwiftErrorValues = SmallVector<const Value*, 1>; |
| /// A function can only have a single swifterror argument. And if it does |
| /// have a swifterror argument, it must be the first entry in |
| /// SwiftErrorVals. |
| SwiftErrorValues SwiftErrorVals; |
| |
| public: |
| /// Initialize data structures for specified new function. |
| void setFunction(MachineFunction &MF); |
| |
| /// Get the (unique) function argument that was marked swifterror, or nullptr |
| /// if this function has no swifterror args. |
| const Value *getFunctionArg() const { |
| return SwiftErrorArg; |
| } |
| |
| /// Get or create the swifterror value virtual register in |
| /// VRegDefMap for this basic block. |
| Register getOrCreateVReg(const MachineBasicBlock *, const Value *); |
| |
| /// Set the swifterror virtual register in the VRegDefMap for this |
| /// basic block. |
| void setCurrentVReg(const MachineBasicBlock *MBB, const Value *, Register); |
| |
| /// Get or create the swifterror value virtual register for a def of a |
| /// swifterror by an instruction. |
| Register getOrCreateVRegDefAt(const Instruction *, const MachineBasicBlock *, |
| const Value *); |
| |
| /// Get or create the swifterror value virtual register for a use of a |
| /// swifterror by an instruction. |
| Register getOrCreateVRegUseAt(const Instruction *, const MachineBasicBlock *, |
| const Value *); |
| |
| /// Create initial definitions of swifterror values in the entry block of the |
| /// current function. |
| bool createEntriesInEntryBlock(DebugLoc DbgLoc); |
| |
| /// Propagate assigned swifterror vregs through a function, synthesizing PHI |
| /// nodes when needed to maintain consistency. |
| void propagateVRegs(); |
| |
| void preassignVRegs(MachineBasicBlock *MBB, BasicBlock::const_iterator Begin, |
| BasicBlock::const_iterator End); |
| }; |
| |
| } |
| |
| #endif |