MFC r318906:

Pull in r303257 from upstream llvm trunk (by Krzysztof Parzyszek)

  [PPC] Properly update register save area offsets

  The variables MinGPR/MinG8R were not updated properly when resetting the
  offsets, which in the included testcase lead to saving the CR register
  in the same location as R30.

  This fixes another issue reported in PR26519.

  Differential Revision: https://reviews.llvm.org/D33017

Reported by:	Mark Millard
PR:		206990

1 files changed, 14 insertions, 9 deletions

diff --git a/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp b/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
index 2c4b17a..f9ea871 100644
--- a/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
+++ b/contrib/llvm/lib/Target/PowerPC/PPCFrameLowering.cpp
@@ -1775,32 +1775,37 @@ void PPCFrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF,
   // Check whether the frame pointer register is allocated. If so, make sure it
   // is spilled to the correct offset.
   if (needsFP(MF)) {
-    HasGPSaveArea = true;
-
     int FI = PFI->getFramePointerSaveIndex();
     assert(FI && "No Frame Pointer Save Slot!");
-
     MFI.setObjectOffset(FI, LowerBound + MFI.getObjectOffset(FI));
+    // FP is R31/X31, so no need to update MinGPR/MinG8R.
+    HasGPSaveArea = true;
   }
 
   if (PFI->usesPICBase()) {
-    HasGPSaveArea = true;
-
     int FI = PFI->getPICBasePointerSaveIndex();
     assert(FI && "No PIC Base Pointer Save Slot!");
-
     MFI.setObjectOffset(FI, LowerBound + MFI.getObjectOffset(FI));
+
+    MinGPR = std::min<unsigned>(MinGPR, PPC::R30);
+    HasGPSaveArea = true;
   }
 
   const PPCRegisterInfo *RegInfo =
       static_cast<const PPCRegisterInfo *>(Subtarget.getRegisterInfo());
   if (RegInfo->hasBasePointer(MF)) {
-    HasGPSaveArea = true;
-
     int FI = PFI->getBasePointerSaveIndex();
     assert(FI && "No Base Pointer Save Slot!");
-
     MFI.setObjectOffset(FI, LowerBound + MFI.getObjectOffset(FI));
+
+    unsigned BP = RegInfo->getBaseRegister(MF);
+    if (PPC::G8RCRegClass.contains(BP)) {
+      MinG8R = std::min<unsigned>(MinG8R, BP);
+      HasG8SaveArea = true;
+    } else if (PPC::GPRCRegClass.contains(BP)) {
+      MinGPR = std::min<unsigned>(MinGPR, BP);
+      HasGPSaveArea = true;
+    }
   }
 
   // General register save area starts right below the Floating-point