Re: g++ doesn't unroll a loop it should unroll

[Geert Bosch <bosch at adacore dot com>]

On Dec 13, 2006, at 17:09, Denis Vlasenko wrote:

> # g++ -c -O3 toto.cpp -o toto.o
> # g++ -DUNROLL -O3 toto.cpp -o toto_unroll.o -c
> # size toto.o toto_unroll.o
>    text    data     bss     dec     hex filename
>     525       8       1     534     216 toto.o
>     359       8       1     368     170 toto_unroll.o
>
> How can C++ compiler know that you are willing to trade
> so much of text size for performance?

Huh? The unrolled version is 30% smaller, isn't it?

  -Geert