[Bug c/59812] Missing aggressive loop optimization warning

[Bug c/59812] Missing aggressive loop optimization warning

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59812

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The warning is documented to warn only about loops with constant number of
iterations.  Generally the number of iterations analysis which computes that
the loop has at most 4 (valid) iterations on the other side doesn't have access
to VRP to see what the values would be here, while for post-VRP it could use
remembered SSA_NAME_RANGE_INFO, during VRP when this is optimized it can't, it
isn't stored there yet.

[Bug middle-end/59812] Missing aggressive loop optimization warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59812

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-01-15
          Component|c                           |middle-end
            Version|unknown                     |4.9.0
     Ever confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.

[Bug middle-end/59812] Missing aggressive loop optimization warning

[ppluzhnikov at google dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59812

--- Comment #3 from Paul Pluzhnikov <ppluzhnikov at google dot com> ---
Reconfirmed @r212875

[Bug middle-end/59812] Missing aggressive loop optimization warning

[development@faf-ltd.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59812

Peter VARGA <development@faf-ltd.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |development@faf-ltd.com

--- Comment #4 from Peter VARGA <development@faf-ltd.com> ---
Good, but why does not produce this test case any warning:

#include <iostream>
#include <complex>
using namespace std;

int main() {
    complex<int> delta;
    complex<int> mc[4] = {0};

    for(int di = 0; di < 4; di++, delta = mc[di]) {
        cout << "di:" << di << " delta:" << delta << endl;
    }

    return 0;
}

it is an endless loop. According this threads
http://stackoverflow.com/questions/32506643/c-compilation-bug ,
http://blog.regehr.org/archives/918 I understand it was fixed.