diff options
Diffstat (limited to 'lib/CodeGen/VirtRegRewriter.cpp')
| -rw-r--r-- | lib/CodeGen/VirtRegRewriter.cpp | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/lib/CodeGen/VirtRegRewriter.cpp b/lib/CodeGen/VirtRegRewriter.cpp index ec149dd..1850658 100644 --- a/lib/CodeGen/VirtRegRewriter.cpp +++ b/lib/CodeGen/VirtRegRewriter.cpp @@ -32,7 +32,7 @@ STATISTIC(NumCommutes, "Number of instructions commuted"); STATISTIC(NumDRM , "Number of re-materializable defs elided"); STATISTIC(NumStores , "Number of stores added"); STATISTIC(NumPSpills , "Number of physical register spills"); -STATISTIC(NumOmitted , "Number of reloads omited"); +STATISTIC(NumOmitted , "Number of reloads omitted"); STATISTIC(NumAvoided , "Number of reloads deemed unnecessary"); STATISTIC(NumCopified, "Number of available reloads turned into copies"); STATISTIC(NumReMats , "Number of re-materialization"); @@ -261,6 +261,10 @@ public: /// now). void ModifyStackSlotOrReMat(int SlotOrReMat); + /// ClobberSharingStackSlots - When a register mapped to a stack slot changes, + /// other stack slots sharing the same register are no longer valid. + void ClobberSharingStackSlots(int StackSlot); + /// AddAvailableRegsToLiveIn - Availability information is being kept coming /// into the specified MBB. Add available physical registers as potential /// live-in's. If they are reused in the MBB, they will be added to the @@ -665,7 +669,7 @@ static void UpdateKills(MachineInstr &MI, const TargetRegisterInfo* TRI, } } -/// ReMaterialize - Re-materialize definition for Reg targetting DestReg. +/// ReMaterialize - Re-materialize definition for Reg targeting DestReg. /// static void ReMaterialize(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MII, @@ -831,6 +835,26 @@ void AvailableSpills::ModifyStackSlotOrReMat(int SlotOrReMat) { PhysRegsAvailable.erase(I); } +void AvailableSpills::ClobberSharingStackSlots(int StackSlot) { + std::map<int, unsigned>::iterator It = + SpillSlotsOrReMatsAvailable.find(StackSlot); + if (It == SpillSlotsOrReMatsAvailable.end()) return; + unsigned Reg = It->second >> 1; + + // Erase entries in PhysRegsAvailable for other stack slots. + std::multimap<unsigned, int>::iterator I = PhysRegsAvailable.lower_bound(Reg); + while (I != PhysRegsAvailable.end() && I->first == Reg) { + std::multimap<unsigned, int>::iterator NextI = llvm::next(I); + if (I->second != StackSlot) { + DEBUG(dbgs() << "Clobbered sharing SS#" << I->second << " in " + << PrintReg(Reg, TRI) << '\n'); + SpillSlotsOrReMatsAvailable.erase(I->second); + PhysRegsAvailable.erase(I); + } + I = NextI; + } +} + // ************************** // // Reuse Info Implementation // // ************************** // @@ -1791,8 +1815,8 @@ bool LocalRewriter::InsertRestores(MachineInstr *MI, else DEBUG(dbgs() << "Reusing SS#" << SSorRMId); DEBUG(dbgs() << " from physreg " - << TRI->getName(InReg) << " for vreg" - << VirtReg <<" instead of reloading into physreg " + << TRI->getName(InReg) << " for " << PrintReg(VirtReg) + <<" instead of reloading into physreg " << TRI->getName(Phys) << '\n'); // Reusing a physreg may resurrect it. But we expect ProcessUses to update @@ -1807,8 +1831,8 @@ bool LocalRewriter::InsertRestores(MachineInstr *MI, else DEBUG(dbgs() << "Reusing SS#" << SSorRMId); DEBUG(dbgs() << " from physreg " - << TRI->getName(InReg) << " for vreg" - << VirtReg <<" by copying it into physreg " + << TRI->getName(InReg) << " for " << PrintReg(VirtReg) + <<" by copying it into physreg " << TRI->getName(Phys) << '\n'); // If the reloaded / remat value is available in another register, @@ -2025,7 +2049,8 @@ void LocalRewriter::ProcessUses(MachineInstr &MI, AvailableSpills &Spills, TRI->regsOverlap(MOk.getReg(), PhysReg)) { CanReuse = false; DEBUG(dbgs() << "Not reusing physreg " << TRI->getName(PhysReg) - << " for vreg" << VirtReg << ": " << MOk << '\n'); + << " for " << PrintReg(VirtReg) << ": " << MOk + << '\n'); break; } } @@ -2039,9 +2064,9 @@ void LocalRewriter::ProcessUses(MachineInstr &MI, AvailableSpills &Spills, else DEBUG(dbgs() << "Reusing SS#" << ReuseSlot); DEBUG(dbgs() << " from physreg " - << TRI->getName(PhysReg) << " for vreg" - << VirtReg <<" instead of reloading into physreg " - << TRI->getName(VRM->getPhys(VirtReg)) << '\n'); + << TRI->getName(PhysReg) << " for " << PrintReg(VirtReg) + << " instead of reloading into " + << PrintReg(VRM->getPhys(VirtReg), TRI) << '\n'); unsigned RReg = SubIdx ? TRI->getSubReg(PhysReg, SubIdx) : PhysReg; MI.getOperand(i).setReg(RReg); MI.getOperand(i).setSubReg(0); @@ -2126,7 +2151,7 @@ void LocalRewriter::ProcessUses(MachineInstr &MI, AvailableSpills &Spills, else DEBUG(dbgs() << "Reusing SS#" << ReuseSlot); DEBUG(dbgs() << " from physreg " << TRI->getName(PhysReg) - << " for vreg" << VirtReg + << " for " << PrintReg(VirtReg) << " instead of reloading into same physreg.\n"); unsigned RReg = SubIdx ? TRI->getSubReg(PhysReg, SubIdx) : PhysReg; MI.getOperand(i).setReg(RReg); @@ -2315,7 +2340,7 @@ LocalRewriter::RewriteMBB(LiveIntervals *LIs, for (unsigned FVI = 0, FVE = FoldedVirts.size(); FVI != FVE; ++FVI) { unsigned VirtReg = FoldedVirts[FVI].first; VirtRegMap::ModRef MR = FoldedVirts[FVI].second; - DEBUG(dbgs() << "Folded vreg: " << VirtReg << " MR: " << MR); + DEBUG(dbgs() << "Folded " << PrintReg(VirtReg) << " MR: " << MR); int SS = VRM->getStackSlot(VirtReg); if (SS == VirtRegMap::NO_STACK_SLOT) @@ -2549,6 +2574,10 @@ LocalRewriter::RewriteMBB(LiveIntervals *LIs, } } + // If StackSlot is available in a register that also holds other stack + // slots, clobber those stack slots now. + Spills.ClobberSharingStackSlots(StackSlot); + assert(PhysReg && "VR not assigned a physical register?"); MRI->setPhysRegUsed(PhysReg); unsigned RReg = SubIdx ? TRI->getSubReg(PhysReg, SubIdx) : PhysReg; |
