[Bug c++/28271] New: Specialization of a function is not called if compile with -03 option

[Bug c++/28271] New: Specialization of a function is not called if compile with -03 option

[maxime dot fiandino at imag dot fr]

The specialization of a function is not called if compile with -03 option,
the generic implementation is called insteed.
This appear only if the declaration of the specialization is in another
file.
The specialization is called if compiled with -02 or lees optimization, or
if the generic implementation is declared with the buildin noinline.

Configuration of gcc -v:

Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: ../src/configure
--prefix=/project/spg/tools/Open-Sources/gcc/4.1.1/Linux-x86/
--enable-__cxa_atexit --enable-shared --enable-long-long --enable-threads
--enable-languages=c,c++ --with-gnu-as --with-gnu-ar --with-gnu-ld --with-gcc
Thread model: posix
gcc version 4.1.1


Three files:

header


#ifndef _TCLASS_H_
#define _TCLASS_H_

template<typename T> bool foo(T val)
{
return false;
}

#endif 

scpecialization:
#include "tclass.h"


template<> bool foo(int val)
{
return true;
}

main:

#include "tclass.h"

int main() {

return(foo(1));

}


-- 
           Summary: Specialization of a function is not called if compile
                    with -03 option
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: maxime dot fiandino at imag dot fr
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28271

[Bug c++/28271] Specialization of a function is not called if compile with -03 option

[maxime dot fiandino at imag dot fr]

------- Comment #1 from maxime dot fiandino at imag dot fr  2006-07-05 13:11 -------
Created an attachment (id=11829)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11829&action=view)
The main, just call the template function foo and return the return value


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28271

[Bug c++/28271] Specialization of a function is not called if compile with -03 option

[maxime dot fiandino at imag dot fr]

------- Comment #2 from maxime dot fiandino at imag dot fr  2006-07-05 13:12 -------
Created an attachment (id=11830)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11830&action=view)
the specialization

The specialization on int return true


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28271

[Bug c++/28271] Specialization of a function is not called if compile with -03 option

[maxime dot fiandino at imag dot fr]

------- Comment #3 from maxime dot fiandino at imag dot fr  2006-07-05 13:12 -------
Created an attachment (id=11831)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11831&action=view)
The header with the generic implementation

The generic template function return false


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28271

[Bug c++/28271] Specialization of a function is not called if compile with -03 option

[maxime dot fiandino at imag dot fr]

------- Comment #4 from maxime dot fiandino at imag dot fr  2006-07-05 13:14 -------
Created an attachment (id=11832)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11832&action=view)
The makefile to test

This makefile create two executable

TC1 compiled with -02 which work well
TC2 compiled with -O3 which don't


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28271

[Bug c++/28271] Specialization of a function is not called if compile with -03 option

[maxime dot fiandino at imag dot fr]

------- Comment #5 from maxime dot fiandino at imag dot fr  2006-07-05 13:18 -------
This bug was firstly discover under gcc3.2.3, then we test with 4.1.1 with the
same results. The test case is very short.


-- 

maxime dot fiandino at imag dot fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |maxime dot fiandino at imag
                   |                            |dot fr
      Known to fail|                            |3.2.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28271

[Bug c++/28271] Specialization of a function is not called if compile with -03 option

[rguenth at gcc dot gnu dot org]

------- Comment #6 from rguenth at gcc dot gnu dot org  2006-07-05 14:04 -------
You need to make the specialization visible at the point of instantiation.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28271

[Bug c++/28271] Specialization of a function is not called if compile with -03 option

[maxime dot fiandino at imag dot fr]

------- Comment #7 from maxime dot fiandino at imag dot fr  2006-07-05 14:33 -------
Thanks, for you quick answer Richard.

Where i don't understand is, it is working well if i declare
the generic template function with:

template<typename T> bool foo(T val) __attribute__(noinline)
{
return false;
}

Just in the case this workaround (perhaps evil) may interest some people.

I return to read the C++ spec this night, i missed this point.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28271