[llvm] r274955 - LivePhysRegs: addLiveOuts() can skip addPristines() in ret block

[Matthias Braun via llvm-commits]

Author: matze
Date: Fri Jul  8 20:31:36 2016
New Revision: 274955

URL: http://llvm.org/viewvc/llvm-project?rev=274955&view=rev
Log:
LivePhysRegs: addLiveOuts() can skip addPristines() in ret block

Drive-by improvement: We would 1) add CSRs, 2) remove callee saved CSRs
and 3) add all CSRs again for the return block.  Just adding CSRs once
obviously gives the same results.

Modified:
    llvm/trunk/lib/CodeGen/LivePhysRegs.cpp

Modified: llvm/trunk/lib/CodeGen/LivePhysRegs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LivePhysRegs.cpp?rev=274955&r1=274954&r2=274955&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LivePhysRegs.cpp (original)
+++ llvm/trunk/lib/CodeGen/LivePhysRegs.cpp Fri Jul  8 20:31:36 2016
@@ -167,12 +167,13 @@ void LivePhysRegs::addLiveOuts(const Mac
   const MachineFunction &MF = *MBB.getParent();
   const MachineFrameInfo &MFI = *MF.getFrameInfo();
   if (MFI.isCalleeSavedInfoValid()) {
-    addPristines(*this, MF, MFI, *TRI);
     if (MBB.isReturnBlock()) {
       // The return block has no successors whose live-ins we could merge
       // below. So instead we add the callee saved registers manually.
       for (const MCPhysReg *I = TRI->getCalleeSavedRegs(&MF); *I; ++I)
         addReg(*I);
+    } else {
+      addPristines(*this, MF, MFI, *TRI);
     }
   }