diff options
Diffstat (limited to 'lib/CodeGen/ExpandPostRAPseudos.cpp')
| -rw-r--r-- | lib/CodeGen/ExpandPostRAPseudos.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/CodeGen/ExpandPostRAPseudos.cpp b/lib/CodeGen/ExpandPostRAPseudos.cpp index ab2382e2db6d8..e860906043dda 100644 --- a/lib/CodeGen/ExpandPostRAPseudos.cpp +++ b/lib/CodeGen/ExpandPostRAPseudos.cpp @@ -142,8 +142,9 @@ bool ExpandPostRA::LowerCopy(MachineInstr *MI) { MachineOperand &DstMO = MI->getOperand(0); MachineOperand &SrcMO = MI->getOperand(1); - if (SrcMO.getReg() == DstMO.getReg()) { - DEBUG(dbgs() << "identity copy: " << *MI); + bool IdentityCopy = (SrcMO.getReg() == DstMO.getReg()); + if (IdentityCopy || SrcMO.isUndef()) { + DEBUG(dbgs() << (IdentityCopy ? "identity copy: " : "undef copy: ") << *MI); // No need to insert an identity copy instruction, but replace with a KILL // if liveness is changed. if (SrcMO.isUndef() || MI->getNumOperands() > 2) { |