[WinEH] Fix stack alignment in funclets and ParentFrameOffset calculation

Our previous value of "16 + 8 + MaxCallFrameSize" for ParentFrameOffset
is incorrect when CSRs are involved. We were supposed to have a test
case to catch this, but it wasn't very rigorous.

The main effect here is that calling _CxxThrowException inside a
catchpad doesn't immediately crash on MOVAPS when you have an odd number
of CSRs.

llvm-svn: 250583

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/include/llvm/Target/TargetFrameLowering.h b/llvm/include/llvm/Target/TargetFrameLowering.h
index 9585f7c3498..398c91ef562 100644
--- a/llvm/include/llvm/Target/TargetFrameLowering.h
+++ b/llvm/include/llvm/Target/TargetFrameLowering.h
@@ -265,6 +265,10 @@ public:
                                              RegScavenger *RS = nullptr) const {
   }
 
+  virtual unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const {
+    report_fatal_error("WinEH not implemented for this target");
+  }
+
   /// eliminateCallFramePseudoInstr - This method is called during prolog/epilog
   /// code insertion to eliminate call frame setup and destroy pseudo
   /// instructions (but only if the Target is using them).  It is responsible