llvm dev - Mar 2012 - [LLVMdev] x86-64 sign extension for parameters and return values

On Thu, Feb 23, 2012 at 3:54 PM, Eli Friedman <eli.friedman at gmail.com>
wrote:
> LLVM has traditionally assumed that all integer argument and return
> types narrower than int are promoted to int on all architectures.
> Nobody has actually noticed any issues with this before now, as far as
> I know.
The only reason that I noticed was that Python ctypes started misbehaving
when we went to build/test it on OS X Lion (http://bugs.python.org/issue13370).
After investigating the failure I found this.  Python uses libffi and
libffi implements
the GCC ABI.  So I would expect any project using libffi with clang to
have problems.
> If gcc has decided to assume no sign/zero-extension on x86-64, we need
> to follow their lead, at least on Linux. Please file at
> http://llvm.org/bugs/ ; an executable testcase to go with this would
> be nice, so we can compare various compilers and different platforms.
Will do.  Thanks.

-- Meador

Hi Meador,

Have you filed a bugzilla report? What's the PR number?

Evan

On Feb 23, 2012, at 3:11 PM, Meador Inge wrote:
> On Thu, Feb 23, 2012 at 3:54 PM, Eli Friedman <eli.friedman at
gmail.com> wrote:
> 
>> LLVM has traditionally assumed that all integer argument and return
>> types narrower than int are promoted to int on all architectures.
>> Nobody has actually noticed any issues with this before now, as far as
>> I know.
> 
> The only reason that I noticed was that Python ctypes started misbehaving
> when we went to build/test it on OS X Lion
(http://bugs.python.org/issue13370).
> After investigating the failure I found this.  Python uses libffi and
> libffi implements
> the GCC ABI.  So I would expect any project using libffi with clang to
> have problems.
> 
>> If gcc has decided to assume no sign/zero-extension on x86-64, we need
>> to follow their lead, at least on Linux. Please file at
>> http://llvm.org/bugs/ ; an executable testcase to go with this would
>> be nice, so we can compare various compilers and different platforms.
> 
> Will do.  Thanks.
> 
> -- Meador
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

On Wed, Mar 7, 2012 at 5:51 PM, Evan Cheng <evan.cheng at apple.com>
wrote:
> Hi Meador,
>
> Have you filed a bugzilla report? What's the PR number?
http://llvm.org/bugs/show_bug.cgi?id=12207

-- Meador