1 files changed, 22 insertions, 0 deletions
diff --git a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
index fa20977ec018..a769fdeff568 100644
--- a/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
@@ -1475,6 +1475,28 @@ void SystemZXPLINKFrameLowering::processFunctionBeforeFrameFinalized(
   // with existing compilers.
   MFFrame.setMaxCallFrameSize(
       std::max(64U, (unsigned)alignTo(MFFrame.getMaxCallFrameSize(), 64)));
+
+  // Add frame values with positive object offsets. Since the displacement from
+  // the SP/FP is calculated by ObjectOffset + StackSize + Bias, object offsets
+  // with positive values are in the caller's stack frame. We need to include
+  // that since it is accessed by displacement to SP/FP.
+  int64_t LargestArgOffset = 0;
+  for (int I = MFFrame.getObjectIndexBegin(); I != 0; ++I) {
+    if (MFFrame.getObjectOffset(I) >= 0) {
+      int64_t ObjOffset = MFFrame.getObjectOffset(I) + MFFrame.getObjectSize(I);
+      LargestArgOffset = std::max(ObjOffset, LargestArgOffset);
+    }
+  }
+
+  uint64_t MaxReach = (StackSize + Regs.getCallFrameSize() +
+                       Regs.getStackPointerBias() + LargestArgOffset);
+
+  if (!isUInt<12>(MaxReach)) {
+    // We may need register scavenging slots if some parts of the frame
+    // are outside the reach of an unsigned 12-bit displacement.
+    RS->addScavengingFrameIndex(MFFrame.CreateStackObject(8, Align(8), false));
+    RS->addScavengingFrameIndex(MFFrame.CreateStackObject(8, Align(8), false));
+  }
 }
 
 // Determines the size of the frame, and creates the deferred spill objects.