G++ 4.3.4 (with Cygwin 1.7) vs.G++ 4.5.2 (with MinGW) ???

G++ 4.3.4 (with Cygwin 1.7) vs.G++ 4.5.2 (with MinGW) ???

[Jan Chludzinski]

Just finished compiling some numerical code (developed using the
Borland C++ compiler) using G++ 4.3.4 (that came with Cygwin 1.7).
The answers are different from what I get using the Borland compiler
(circa 2002).  I have known correct answers from some NASA code and
compare against those.

I've transitioned of late to Code::Blocks using the latest MinGW.
MinGW comes with G++ 4.5.2.  I compiled using this compiler and it
once again it works (I get the same answers as the NASA code).

Are there known problems with G++ 4.3.4?

BTW, the original code was infinite looping until I replaced the old style:

for (i=0; i<WHATEVER; i++) ..

with i declared within the routine (i.e., function) with:

for (int i=0; i<WHATEVER; i++) ...

---John

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Re: G++ 4.3.4 (with Cygwin 1.7) vs.G++ 4.5.2 (with MinGW) ???

[Larry Hall (Cygwin)]

On 6/13/2011 2:46 AM, Jan Chludzinski wrote:
> Just finished compiling some numerical code (developed using the
> Borland C++ compiler) using G++ 4.3.4 (that came with Cygwin 1.7).
> The answers are different from what I get using the Borland compiler
> (circa 2002).  I have known correct answers from some NASA code and
> compare against those.
>
> I've transitioned of late to Code::Blocks using the latest MinGW.
> MinGW comes with G++ 4.5.2.  I compiled using this compiler and it
> once again it works (I get the same answers as the NASA code).
>
> Are there known problems with G++ 4.3.4?
>
> BTW, the original code was infinite looping until I replaced the old style:
>
> for (i=0; i<WHATEVER; i++) ..
>
> with i declared within the routine (i.e., function) with:
>
> for (int i=0; i<WHATEVER; i++) ...

Try turning off optimizations or at least drop back to -O3.


-- 
Larry

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