Re: [Bug-gsl] SV decomp failure

[Steve Brosnan]

Hi Alexey,

Thanks for your comments.

Actually we have tried to narrow down the optimization problem by progressively 
adding in optimization options, but the results were confusing. See this link:
http://lists.gnu.org/archive/html/bug-gsl/2012-09/msg00036.html
Please shed some light on this if possible.

Also, by extracting the SV-decomp tests and adding in any files needed to 
compile I did use Xcode to do the test with the Apple LLVM compiler 4.1 (which 
I think uses clang and is now the default Xcode compiler). The tests succeed 
for all optimization options, including -O2. See prior link.

What I don't know is how to tell the gsl build mechanism to use that compiler. 
The Mac compilation tools have gcc being symbolically linked to the 
llvm-gcc-4.2 compiler. But I have not been able to locate the Apple LLVM 
compiler 4.1 in the file system. And I do not know if that compiler uses the 
gcc syntax. Any help is appreciated.

Best regards,

Steve Brosnan


On Oct 25, 2012, at 5:00 PM, "Alexey A. Illarionov" <address@hidden> wrote:

> Hi,
> 
> Steve Brosnan wrote:
> 
> I think so, since problem can be removed with a different optimization
> flag choice. I'm not a Mac user so can't really help, but you can try
> the following
> 
> - Try building GSL with clang, and see if this the problem is gone.
> 
> - In the gcc manual (man gcc) there is a detailed explanation what -Os
> and -O2 mean. You can bisect the difference of these two sets and see
> what option exactly causing this bug.
> 
> 
> 
> Best regards,
> Alexey A. Illarionov