Not all PPC functions with a frame pointer need a RS spill slot

We used to add a spill slot for the register scavenger whenever the function
has a frame pointer. This is unnecessarily conservative: We may need the spill
slot for dynamic stack allocations, and functions with dynamic stack
allocations always have a FP, but we might also have a FP for other reasons
(such as the user explicitly disabling frame-pointer elimination), and we don't
necessarily need a spill slot for those functions.

The structsinregs test needed adjustment because it disables FP elimination.

llvm-svn: 177106

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp b/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
index 0a396e6693f..a93c9443442 100644
--- a/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
@@ -831,7 +831,7 @@ PPCFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
   //        r0 for now.
 
   if (RegInfo->requiresRegisterScavenging(MF))
-    if (needsFP(MF) || spillsCR(MF)) {
+    if (MFI->hasVarSizedObjects() || spillsCR(MF)) {
       const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
       const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
       const TargetRegisterClass *RC = isPPC64 ? G8RC : GPRC;