diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/ARM/ARMBaseInstrInfo.cpp | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp index 4cb2407aeb..80961bff77 100644 --- a/lib/Target/ARM/ARMBaseInstrInfo.cpp +++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp @@ -660,26 +660,27 @@ ARMBaseInstrInfo::copyRegToReg(MachineBasicBlock &MBB, } else if (DestRC == ARM::DPRRegisterClass) { const ARMBaseRegisterInfo* TRI = &getRegisterInfo(); + // If we do not found an instruction defining the reg, this means the + // register should be live-in for this BB. It's always to better to use + // NEON reg-reg moves. + unsigned Domain = ARMII::DomainNEON; + // Find the Machine Instruction which defines SrcReg. - MachineBasicBlock::iterator J = (I == MBB.begin() ? I : prior(I)); - while (J != MBB.begin()) { - if (J->modifiesRegister(SrcReg, TRI)) - break; - --J; - } + if (!MBB.empty()) { + MachineBasicBlock::iterator J = (I == MBB.begin() ? I : prior(I)); + while (J != MBB.begin()) { + if (J->modifiesRegister(SrcReg, TRI)) + break; + --J; + } - unsigned Domain; - if (J->modifiesRegister(SrcReg, TRI)) { - Domain = J->getDesc().TSFlags & ARMII::DomainMask; - // Instructions in general domain are subreg accesses. - // Map them to NEON reg-reg moves. - if (Domain == ARMII::DomainGeneral) - Domain = ARMII::DomainNEON; - } else { - // We reached the beginning of the BB and found no instruction defining - // the reg. This means that register should be live-in for this BB. - // It's always to better to use NEON reg-reg moves. - Domain = ARMII::DomainNEON; + if (J->modifiesRegister(SrcReg, TRI)) { + Domain = J->getDesc().TSFlags & ARMII::DomainMask; + // Instructions in general domain are subreg accesses. + // Map them to NEON reg-reg moves. + if (Domain == ARMII::DomainGeneral) + Domain = ARMII::DomainNEON; + } } if ((Domain & ARMII::DomainNEON) && getSubtarget().hasNEON()) { |