diff options
Diffstat (limited to 'llvm/lib/CodeGen/MachineCopyPropagation.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/MachineCopyPropagation.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/MachineCopyPropagation.cpp b/llvm/lib/CodeGen/MachineCopyPropagation.cpp index 26110a1..3453e6c 100644 --- a/llvm/lib/CodeGen/MachineCopyPropagation.cpp +++ b/llvm/lib/CodeGen/MachineCopyPropagation.cpp @@ -462,8 +462,7 @@ bool MachineCopyPropagation::eraseIfRedundant(MachineInstr &Copy, auto PrevCopyOperands = isCopyInstr(*PrevCopy, *TII, UseCopyInstr); // Check that the existing copy uses the correct sub registers. - if (PrevCopyOperands->Destination->isDead() || - PrevCopyOperands->Source->isUndef()) + if (PrevCopyOperands->Destination->isDead()) return false; if (!isNopCopy(*PrevCopy, Src, Def, TRI, TII, UseCopyInstr)) return false; @@ -482,6 +481,12 @@ bool MachineCopyPropagation::eraseIfRedundant(MachineInstr &Copy, make_range(PrevCopy->getIterator(), Copy.getIterator())) MI.clearRegisterKills(CopyDef, TRI); + // Clear undef flag from remaining copy if needed. + if (!CopyOperands->Source->isUndef()) { + PrevCopy->getOperand(PrevCopyOperands->Source->getOperandNo()) + .setIsUndef(false); + } + Copy.eraseFromParent(); Changed = true; ++NumDeletes; |