Re: Implement stack arrays even for unknown sizes

[Tobias Burnus <burnus at net-b dot de>]

Tobias Burnus wrote:
>                                  no stack-arrays    with stack-arrays
> + -fwhole-program -flto:                   10.1s          8.9s
> + -fwhole-program -flto -finline-limit=600  4.8s          3.6s

I wonder whether the following is special to my system* or generally 
true. I use:
gfortran -O3 -march=native -ffast-math -funroll-loops -fwhole-program 
-finline-limit=600 fatigue.f90

       no stack-arrays  with stack-arrays
       0m6.622s         0m8.174s
-flto  0m8.444s         0m8.174s

Thus, the non "-flto" version is faster (in particular without stack 
arrays). I assume that it has to do with the declaration issues of the 
front end. However, the last time I tried to find the problem, I failed 
to spot anything which looked wrong - especially, the UIDs seemed to be 
OK. (Besides, I would like to have the -fno-lto performance also with 
.-flto ... ;-)

Tobias

* AMD Athlon(tm) 64 X2 Dual Core Processor 4800+ (2.4 GHz), x86-64 Linux