diff options
Diffstat (limited to 'lib/CodeGen/LiveRangeEdit.cpp')
| -rw-r--r-- | lib/CodeGen/LiveRangeEdit.cpp | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp index 27c57d5f3029..08bbe0c3f379 100644 --- a/lib/CodeGen/LiveRangeEdit.cpp +++ b/lib/CodeGen/LiveRangeEdit.cpp @@ -218,6 +218,22 @@ bool LiveRangeEdit::foldAsLoad(LiveInterval *LI, return true; } +bool LiveRangeEdit::useIsKill(const LiveInterval &LI, + const MachineOperand &MO) const { + const MachineInstr *MI = MO.getParent(); + SlotIndex Idx = LIS.getInstructionIndex(MI).getRegSlot(); + if (LI.Query(Idx).isKill()) + return true; + const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo(); + unsigned SubReg = MO.getSubReg(); + unsigned LaneMask = TRI.getSubRegIndexLaneMask(SubReg); + for (const LiveInterval::SubRange &S : LI.subranges()) { + if ((S.LaneMask & LaneMask) != 0 && S.Query(Idx).isKill()) + return true; + } + return false; +} + /// Find all live intervals that need to shrink, then remove the instruction. void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink) { assert(MI->allDefsAreDead() && "Def isn't really dead"); @@ -266,9 +282,8 @@ void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink) { // unlikely to change anything. We typically don't want to shrink the // PIC base register that has lots of uses everywhere. // Always shrink COPY uses that probably come from live range splitting. - if (MI->readsVirtualRegister(Reg) && - (MI->isCopy() || MOI->isDef() || MRI.hasOneNonDBGUse(Reg) || - LI.Query(Idx).isKill())) + if ((MI->readsVirtualRegister(Reg) && (MI->isCopy() || MOI->isDef())) || + (MOI->readsReg() && (MRI.hasOneNonDBGUse(Reg) || useIsKill(LI, *MOI)))) ToShrink.insert(&LI); // Remove defined value. |