[PATCH] D13767: [X86] Fix more -Os + EH issues

[Michael Kuperstein via llvm-commits]

mkuper added inline comments.

================
Comment at: lib/Target/X86/X86FrameLowering.cpp:2097
@@ -2096,3 +2096,3 @@
     bool HasDwarfEHHandlers =
       !MF.getTarget().getMCAsmInfo()->usesWindowsCFI() &&
       !MF.getMMI().getLandingPads().empty();
----------------
mkuper wrote:
> rnk wrote:
> > Can we just assert up front that we don't need to produce UNWIND_INFO .xdata for Windows? This call frame optimization stuff only fires for 32-bit x86, which doesn't use UNWIND_INFO.
> Sure. Should I just assert on usesWindowsCFI()?
On second thought, no, we can't. It's possible not to have a reserved call frame even without pushes (currently happens e.g. if there are variable-length arrays on the stack). In this case we'll also have an FP, so outgoing arguments will use ebp-based movs.


http://reviews.llvm.org/D13767