[llvm] r269697 - [AArch64] Fix bug in large stack spill slot handling (PR27717)

[Geoff Berry via llvm-commits]

Author: gberry
Date: Mon May 16 15:52:28 2016
New Revision: 269697

URL: http://llvm.org/viewvc/llvm-project?rev=269697&view=rev
Log:
[AArch64] Fix bug in large stack spill slot handling (PR27717)

Summary:
Fix bug in MachO path where a frame index offset would not be reserved
for handling large frames when an extra non-used callee-save register
was saved.  In the case where the extra register is reserved or not a
GPR (e.g. %FP in the MachO case), this would lead to the register
scavenger later failing when called from PrologEpilogInserter.

Reviewers: t.p.northover

Subscribers: aemerson, rengolin, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D20185

Modified:
    llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp

Modified: llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp?rev=269697&r1=269696&r2=269697&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64FrameLowering.cpp Mon May 16 15:52:28 2016
@@ -1126,7 +1126,9 @@ void AArch64FrameLowering::determineCall
     // FIXME: the usual format is actually better if unwinding isn't needed.
     if (produceCompactUnwindFrame(MF) && !SavedRegs.test(PairedReg)) {
       SavedRegs.set(PairedReg);
-      ExtraCSSpill = true;
+      if (AArch64::GPR64RegClass.contains(PairedReg) &&
+          !RegInfo->isReservedReg(MF, PairedReg))
+        ExtraCSSpill = true;
     }
   }