# Strange behavior of \`ifort\`

**URL:** <https://fortran-lang.discourse.group/t/strange-behavior-of-ifort/4846>\
**Category:** Uncategorized\
**Created:** [December 2, 2022, 12:58pm UTC](https://fortran-lang.discourse.group/t/strange-behavior-of-ifort/4846 "2022-12-02T12:58:03Z")\
**Posts on this page:** 1\
**Showing post:** 13

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**Author:** ![CRquantum](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/crquantum/32/730_2.png) [@CRquantum](https://fortran-lang.discourse.group/u/CRquantum)\
**Post date:** [December 2, 2022, 10:56pm UTC](https://fortran-lang.discourse.group/t/strange-behavior-of-ifort/4846/13 "2022-12-02T22:56:11Z")

</div>

> [@zaikunzhang](#):
>
> ```auto
> ! test.f90                                                                                                                           
> program test                                                                                                                         
>                                                                                                                                      
> implicit none                                                                                                                                                                                                        
>                                                                                                                                      
> ! Why these strange numbers? Because they come from a real project.                                                                  
> real, parameter :: A(25) = &                                                                                                         
> & [1.2409463E+22, 2.8192031E+20, -4.4971432E+21, 1.1558917E+22, -4.7725394E+21, &                                                
> & 2.8192031E+20, 2.8192031E+20, -3.2276437E+21, -3.3936284E+21, 4.1412172E+21, &                                                 
> & -4.4971432E+21, -3.2276437E+21, -7.6997325E+20, -4.1627641E+21, -3.4729614E+20,&                                               
> & 1.1558917E+22, -3.3936284E+21, -4.1627641E+21, 2.5757004E+21, -2.4898961E+21, &                                                
> & -4.7725394E+21, 4.1412172E+21, -3.4729614E+20, -2.4898961E+21, 3.5042103E+21]                                                  
>                                                                                                                                      
> real :: S(5, 5)                                                                                                                      
>                                                                                                                                      
> S = reshape(A, [5, 5])                                                                                                               
>                                                                                                                                      
> ! Is S symmetric?                                                                                                                    
> write (*, *) all(abs(S - transpose(S)) <= 0)                                                                                         
>                                                                                                                                      
> ! The numbers in S are horrible. Let's scale it.                                                                                     
> S = S / maxval(abs(S))                                                                                                               
>                                                                                                                                      
> write (*, *) S                                                                                                                       
>                                                                                                                                      
> ! Is S symmetric?                                                                                                                    
> write (*, *) all(abs(S - transpose(S)) <= 0)                                                                                         
>                                                                                                                                      
> end program test            
> 
> ```

I can confirm this issue for ifort.

However, if I define

```auto
integer, parameter :: r8=selected_real_kind(15,9)                                                                                                                      

```

and use

```auto
real(kind=r8)

```

instead of `real`. Then it print T and T.

Perhaps can go to Intel website and report this issue.

---

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