Re: [Bug-gnubg] Re: gnubg bug?

[Michael Petch]

I am finally at home and I can confirm  what Phillipe is seeing. I am using
Debian Lenny (Stable) - 32 Bit

gcc -v 

Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.3.2-1.1'
--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --enable-nls
--with-gxx-include-dir=/usr/include/c++/4.3 --program-suffix=-4.3
--enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr
--enable-targets=all --enable-cld --enable-checking=release
--build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.3.2 (Debian 4.3.2-1.1)

If I pull latest CVS source and do:

./autogen.sh
./configure   --enable-sse=no --disable-threads

I disabled SSE to eliminate it as a factor as well as turned off threads.
Makefile shows SSE is off, and Threads are off. The makefiles end up use "-g
-O2" as default Flags. If I build and run this I see the same behavior as
windows (And what has been reported). The top move in the posted position (
Position ID: NwAAgN3MAGgBAA Match ID: cAnmAEAAIAAA). This is with Pruning
ON. The result is 20/16 19/18 instead of 21/17 19/18. If I turn Pruning off
in evaluations, save settings, exit gnubg and return I get the corretc
results.

Now its my belief that Pruning just masks the problem (not root cause).
Because if I do a build with this (in a clean diretcory):

CXXFLAGS="-g" CFLAGS="-g" CPPFLAGS="-g" ./configure   --enable-sse=no
--disable-threads 

The program then runs properly whether pruning is ON or OFF and the 21/17
19/18 play is correctly identified as best.

The only things I can conclude are that
A) This isn't a thread issue
B) This isn't an SSE issue
C) This seems to be a compiler optimization issue
D) It problem can appear on 32 Bit Linux platforms, on BSD, as well as
windows

I have seen this in the past as well. This was why I stopped using pruning
when I got faster equipment. I always assumed it was "Pruning" at fault but
it was working as expected. Looks like there is an issue. but "Pruning"
masks the root cause which is  probably Optimizations/Compiler related.

On 04/08/09 4:34 PM, "Philippe Michel" <address@hidden> wrote:

> On Tue, 4 Aug 2009, Christian Anthon wrote:
> 
>> This is quite odd. My local linux version doesn't seem to have this
>> problem. Anybody with their own builds having this problem?
> 
> I have the problem with the current cvs source built with the default
> flags (CFLAGS = -g -O2) but not if I compile it without -O2.
> 
> This is on FreeBSD 7.2, gcc 4.2.1 on an old laptop (no SSE).
> 
> 
> 
> 
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