diff --git a/lib/Target/PowerPC/PPCFrameLowering.h b/lib/Target/PowerPC/PPCFrameLowering.h
index d09e47f..a07c170 100644
--- a/lib/Target/PowerPC/PPCFrameLowering.h
+++ b/lib/Target/PowerPC/PPCFrameLowering.h
@@ -144,6 +144,9 @@
       return 0;
     }
 
+    // Note that the offsets here overlap, but this is fixed up in
+    // processFunctionBeforeFrameFinalized.
+
     static const SpillSlot Offsets[] = {
       // Floating-point register save area offsets.
       {PPC::F31, -8},