[cfe-dev] Clang i386-pc-win32 struct return-by-value doesn't match MSVC

[Eli Friedman]

On Sun, Jan 1, 2012 at 11:41 AM, Joe Groff <arcata at gmail.com> wrote:
> Hi everyone. It looks like, when targeting msvc x86-32 (triple
> i?86-pc-win32), Clang still returns all structs by hidden pointer,
> although MSVC returns structs sized {8,4,3,2,1} bytes in registers as
> documented at http://msdn.microsoft.com/en-us/library/984x0h58.aspx .

Yes, a bug.  Please file at llvm.org/bugs/ , or if you're interested
you can try writing a patch yourself.  The relevant code is
lib/CodeGen/TargetInfo.cpp in clang.

-Eli