From f5b42730589f63e5000102a288ce198ce449d98d Mon Sep 17 00:00:00 2001 From: Matthias Braun Date: Wed, 27 May 2015 05:12:39 +0000 Subject: [PATCH] MachineBasicBlock: Cleanup computeRegisterLiveness() - Clean documentation comment - Change the API to accept an iterator so you can actually pass MachineBasicBlock::end() now. - Add more "const". git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238288 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/MachineBasicBlock.h | 17 +++++++------- lib/CodeGen/MachineBasicBlock.cpp | 30 +++++++++++------------- 2 files changed, 23 insertions(+), 24 deletions(-) diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h index 118836ecbf6..357aef0ee60 100644 --- a/include/llvm/CodeGen/MachineBasicBlock.h +++ b/include/llvm/CodeGen/MachineBasicBlock.h @@ -633,17 +633,18 @@ public: ///< neighborhood. }; - /// computeRegisterLiveness - Return whether (physical) register \c Reg - /// has been ined and not ed as of just before \c MI. + /// Return whether (physical) register \p Reg has been ined and not + /// ed as of just before \p Before. /// - /// Search is localised to a neighborhood of - /// \c Neighborhood instructions before (searching for defs or kills) and - /// Neighborhood instructions after (searching just for defs) MI. + /// Search is localised to a neighborhood of \p Neighborhood instructions + /// before (searching for defs or kills) and \p Neighborhood instructions + /// after (searching just for defs) \p Before. /// - /// \c Reg must be a physical register. + /// \p Reg must be a physical register. LivenessQueryResult computeRegisterLiveness(const TargetRegisterInfo *TRI, - unsigned Reg, MachineInstr *MI, - unsigned Neighborhood=10); + unsigned Reg, + const_iterator Before, + unsigned Neighborhood=10) const; // Debugging methods. void dump() const; diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index 937d3703718..d5fdf8ed7a0 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -1129,21 +1129,19 @@ getWeightIterator(MachineBasicBlock::const_succ_iterator I) const { /// instructions after (searching just for defs) MI. MachineBasicBlock::LivenessQueryResult MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, - unsigned Reg, MachineInstr *MI, - unsigned Neighborhood) { + unsigned Reg, const_iterator Before, + unsigned Neighborhood) const { unsigned N = Neighborhood; - MachineBasicBlock *MBB = MI->getParent(); - // Start by searching backwards from MI, looking for kills, reads or defs. - - MachineBasicBlock::iterator I(MI); + // Start by searching backwards from Before, looking for kills, reads or defs. + const_iterator I(Before); // If this is the first insn in the block, don't search backwards. - if (I != MBB->begin()) { + if (I != begin()) { do { --I; MachineOperandIteratorBase::PhysRegInfo Analysis = - MIOperands(I).analyzePhysReg(Reg, TRI); + ConstMIOperands(I).analyzePhysReg(Reg, TRI); if (Analysis.Defines) // Outputs happen after inputs so they take precedence if both are @@ -1158,15 +1156,15 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, // Defined or read without a previous kill - live. return Analysis.Reads ? LQR_Live : LQR_OverlappingLive; - } while (I != MBB->begin() && --N > 0); + } while (I != begin() && --N > 0); } // Did we get to the start of the block? - if (I == MBB->begin()) { + if (I == begin()) { // If so, the register's state is definitely defined by the live-in state. for (MCRegAliasIterator RAI(Reg, TRI, /*IncludeSelf=*/true); RAI.isValid(); ++RAI) { - if (MBB->isLiveIn(*RAI)) + if (isLiveIn(*RAI)) return (*RAI == Reg) ? LQR_Live : LQR_OverlappingLive; } @@ -1175,13 +1173,13 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, N = Neighborhood; - // Try searching forwards from MI, looking for reads or defs. - I = MachineBasicBlock::iterator(MI); + // Try searching forwards from Before, looking for reads or defs. + I = const_iterator(Before); // If this is the last insn in the block, don't search forwards. - if (I != MBB->end()) { - for (++I; I != MBB->end() && N > 0; ++I, --N) { + if (I != end()) { + for (++I; I != end() && N > 0; ++I, --N) { MachineOperandIteratorBase::PhysRegInfo Analysis = - MIOperands(I).analyzePhysReg(Reg, TRI); + ConstMIOperands(I).analyzePhysReg(Reg, TRI); if (Analysis.ReadsOverlap) // Used, therefore must have been live.