diff options
Diffstat (limited to 'lib/CodeGen/RegAllocLocal.cpp')
-rw-r--r-- | lib/CodeGen/RegAllocLocal.cpp | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/lib/CodeGen/RegAllocLocal.cpp b/lib/CodeGen/RegAllocLocal.cpp index cbb5826ce9..6a09bd9816 100644 --- a/lib/CodeGen/RegAllocLocal.cpp +++ b/lib/CodeGen/RegAllocLocal.cpp @@ -838,6 +838,18 @@ void RALocal::AllocateBasicBlock(MachineBasicBlock &MBB) { } } + // If a DEBUG_VALUE says something is located in a spilled register, + // change the DEBUG_VALUE to be undef, which prevents the register + // from being reloaded here. Doing that would change the generated + // code, unless another use immediately follows this instruction. + if (MI->getOpcode()==TargetInstrInfo::DEBUG_VALUE && + MI->getNumOperands()==3 && MI->getOperand(0).isReg()) { + unsigned VirtReg = MI->getOperand(0).getReg(); + if (VirtReg && TargetRegisterInfo::isVirtualRegister(VirtReg) && + !getVirt2PhysRegMapSlot(VirtReg)) + MI->getOperand(0).setReg(0U); + } + // Get the used operands into registers. This has the potential to spill // incoming values if we are out of registers. Note that we completely // ignore physical register uses here. We assume that if an explicit |