Re: [Toon-members] Weird signed overflow warning

[E. Rosten]

On Tue, 1 Jun 2010, Pekka Paalanen wrote:

> Hi,
>
> my code produces a weird warning in TooN. The attached source file is a
> minimal example triggering the warning:
>
> $ bash gcc-warnings2.cc
>
> + g++ -O2 -Wall -Wextra -I.. -llapack gcc-warnings2.cc -o gcc-warnings2

OK, this is a bit of a weird one, and I can't see any way to suppress the 
warning by changing the code. Essentially, it is warning that code written 
with broken assumptions about C++ may break. However, we aren't using 
broken assumptions.

C++ can only do compile-time size checks on static matrices, so TooN uses 
run-time checks for dynamically sized matrices. However, gcc has deduced 
that it can really determine the size of your matrices at compile 
time. This allows it to optimize away the size checks because it 
determines the test is always false. This is good, by the way.

-Ed



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