[PPL-devel] Fwd: ppl 0.11.2 vs llvm

[Roberto Bagnara]

On 08/07/11 18:20, Jack Howarth wrote:
> On Sun, Aug 07, 2011 at 05:41:28PM +0200, Roberto Bagnara wrote:
>> On 08/07/11 17:33, Jack Howarth wrote:
>>> On Sun, Aug 07, 2011 at 05:23:15PM +0200, Roberto Bagnara wrote:
>> I am pretty confident this is a compiler bug.
>>
>>>     Is --disable-fpmath our only option here?
>>
>> The only other option I see is to debug the compiler bug.
>
> You are talking about the failures seen without --disable-fpmath, correct?
> Is this really a compiler bug with clang? I thought it was due to the fact that
> ppl is coded to expect a functional -frounding-math option to be present. This isn't
> really a compiler bug but a compiler limitation, no?

Perhaps I misinterpreted you.  You wrote:

 >>>     The results for llvm-gcc-4.2 from Xcode 4.1 weren't as positive. The testcase...
 >>>
 >>> /bin/sh: line 1: 91482 Segmentation fault: 11  ${dir}$tst
 >>> FAIL: simplifyusingcontext1
 >>>
 >>> segfaults with --disable-fpmath. I wouldn't worry too much about that as Apple is
 >>> using a much older llvm release for llvm-gcc-4.2 than clang3.0svn in Xcode 4.1.
 >>> Also, their usual response to llvm-gcc bugs is that it is being depreciated in
 >>> favor of clang and to use that compiler instead.

I took that as "the PPL testsuite segfaults with some old compiler version (and only
that one) even when configure with --disable-fpmath".  My guess is that that old
compiler version is miscompiling the PPL.

-- 
Prof. Roberto Bagnara
Applied Formal Methods Laboratory
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it