[llvm] r175765 - Revert r175688 - It broke a test case (see PR15320).

[Chandler Carruth]

Thanks!
On Feb 21, 2013 9:04 AM, "Lang Hames" <lhames at gmail.com> wrote:

> Author: lhames
> Date: Thu Feb 21 11:01:59 2013
> New Revision: 175765
>
> URL: http://llvm.org/viewvc/llvm-project?rev=175765&view=rev
> Log:
> Revert r175688 - It broke a test case (see PR15320).
>
> Modified:
>     llvm/trunk/lib/CodeGen/ExpandPostRAPseudos.cpp
>
> Modified: llvm/trunk/lib/CodeGen/ExpandPostRAPseudos.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ExpandPostRAPseudos.cpp?rev=175765&r1=175764&r2=175765&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/ExpandPostRAPseudos.cpp (original)
> +++ llvm/trunk/lib/CodeGen/ExpandPostRAPseudos.cpp Thu Feb 21 11:01:59 2013
> @@ -49,6 +49,8 @@ private:
>    bool LowerSubregToReg(MachineInstr *MI);
>    bool LowerCopy(MachineInstr *MI);
>
> +  void TransferDeadFlag(MachineInstr *MI, unsigned DstReg,
> +                        const TargetRegisterInfo *TRI);
>    void TransferImplicitDefs(MachineInstr *MI);
>  };
>  } // end anonymous namespace
> @@ -59,6 +61,21 @@ char &llvm::ExpandPostRAPseudosID = Expa
>  INITIALIZE_PASS(ExpandPostRA, "postrapseudos",
>                  "Post-RA pseudo instruction expansion pass", false, false)
>
> +/// TransferDeadFlag - MI is a pseudo-instruction with DstReg dead,
> +/// and the lowered replacement instructions immediately precede it.
> +/// Mark the replacement instructions with the dead flag.
> +void
> +ExpandPostRA::TransferDeadFlag(MachineInstr *MI, unsigned DstReg,
> +                               const TargetRegisterInfo *TRI) {
> +  for (MachineBasicBlock::iterator MII =
> +        prior(MachineBasicBlock::iterator(MI)); ; --MII) {
> +    if (MII->addRegisterDead(DstReg, TRI))
> +      break;
> +    assert(MII != MI->getParent()->begin() &&
> +           "copyPhysReg output doesn't reference destination register!");
> +  }
> +}
> +
>  /// TransferImplicitDefs - MI is a pseudo-instruction, and the lowered
>  /// replacement instructions immediately precede it.  Copy any
> implicit-def
>  /// operands from MI to the replacement instruction.
> @@ -111,17 +128,17 @@ bool ExpandPostRA::LowerSubregToReg(Mach
>      }
>      DEBUG(dbgs() << "subreg: eliminated!");
>    } else {
> -    if (MI->getOperand(0).isDead()) {
> -      MI->setDesc(TII->get(TargetOpcode::KILL));
> -      DEBUG(dbgs() << "subreg: replaced by: " << *MI);
> -      return true;
> -    }
>      TII->copyPhysReg(*MBB, MI, MI->getDebugLoc(), DstSubReg, InsReg,
>                       MI->getOperand(2).isKill());
> +
>      // Implicitly define DstReg for subsequent uses.
>      MachineBasicBlock::iterator CopyMI = MI;
>      --CopyMI;
>      CopyMI->addRegisterDefined(DstReg);
> +
> +    // Transfer the kill/dead flags, if needed.
> +    if (MI->getOperand(0).isDead())
> +      TransferDeadFlag(MI, DstSubReg, TRI);
>      DEBUG(dbgs() << "subreg: " << *CopyMI);
>    }
>
> @@ -134,18 +151,11 @@ bool ExpandPostRA::LowerCopy(MachineInst
>    MachineOperand &DstMO = MI->getOperand(0);
>    MachineOperand &SrcMO = MI->getOperand(1);
>
> -  if (DstMO.isDead()) {
> -    DEBUG(dbgs() << "dead copy: " << *MI);
> -    MI->setDesc(TII->get(TargetOpcode::KILL));
> -    DEBUG(dbgs() << "replaced by: " << *MI);
> -    return true;
> -  }
> -
>    if (SrcMO.getReg() == DstMO.getReg()) {
>      DEBUG(dbgs() << "identity 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) {
> +    if (DstMO.isDead() || SrcMO.isUndef() || MI->getNumOperands() > 2) {
>        // We must make sure the super-register gets killed. Replace the
>        // instruction with KILL.
>        MI->setDesc(TII->get(TargetOpcode::KILL));
> @@ -161,6 +171,8 @@ bool ExpandPostRA::LowerCopy(MachineInst
>    TII->copyPhysReg(*MI->getParent(), MI, MI->getDebugLoc(),
>                     DstMO.getReg(), SrcMO.getReg(), SrcMO.isKill());
>
> +  if (DstMO.isDead())
> +    TransferDeadFlag(MI, DstMO.getReg(), TRI);
>    if (MI->getNumOperands() > 2)
>      TransferImplicitDefs(MI);
>    DEBUG({
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20130221/37645cfd/attachment.html>