diff --git a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp index 7369577e1242..f51bedd3347f 100644 --- a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -1640,8 +1640,8 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) { else if (RealSrcReg) SavedLI.reset(li_->dupInterval(&DstInt)); - // Check if it is necessary to propagate "isDead" property. if (!isExtSubReg && !isInsSubReg && !isSubRegToReg) { + // Check if it is necessary to propagate "isDead" property. MachineOperand *mopd = CopyMI->findRegisterDefOperand(DstReg, false); bool isDead = mopd->isDead(); @@ -1690,16 +1690,15 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) { // been modified, so we can use this information below to update aliases. bool Swapped = false; // If SrcInt is implicitly defined, it's safe to coalesce. - bool isEmpty = SrcInt.empty(); - if (isEmpty && !CanCoalesceWithImpDef(CopyMI, DstInt, SrcInt)) { - // Only coalesce an empty interval (defined by implicit_def) with - // another interval which has a valno defined by the CopyMI and the CopyMI - // is a kill of the implicit def. - DEBUG(dbgs() << "Not profitable!\n"); - return false; - } - - if (!isEmpty && !JoinIntervals(DstInt, SrcInt, Swapped)) { + if (SrcInt.empty()) { + if (!CanCoalesceWithImpDef(CopyMI, DstInt, SrcInt)) { + // Only coalesce an empty interval (defined by implicit_def) with + // another interval which has a valno defined by the CopyMI and the CopyMI + // is a kill of the implicit def. + DEBUG(dbgs() << "Not profitable!\n"); + return false; + } + } else if (!JoinIntervals(DstInt, SrcInt, Swapped)) { // Coalescing failed. // If definition of source is defined by trivial computation, try