<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/64173>64173</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [Flang] Poor performance of code with transfer intrinsic
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            performance,
            flang
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          kiranchandramohan
      </td>
    </tr>
</table>

<pre>
    Code with transfer intrinsic is much slower with flang compared to gfortran.

**Source**
```
program test
  implicit none
 Integer*8 :: mysum = 0
  real :: r
  integer :: i,j,k
  r = 1.2
 Do k = 1, 10
    Do j = 1, 2156
      Do i = 1, 2156
        call sum4(mysum, r)
      End Do
    End Do
  End Do
 write(*,*)'checksum =', mysum
end program test

subroutine sum4 (mysum, r)
  implicit none 
  Integer*8, intent (inout) :: mysum
 Real, intent (in) :: r
  Integer*1 i4(4)
  i4 = transfer(r, i4)
 mysum = ((((mysum + i4(1)) + i4(2)) + i4(3)) + i4(4))
  Return
end subroutine sum4
```

**Run time**
```
$ ./bin/flang-new -O3 transfer.f90
$ time ./a.out 
 checksum = -11388423200

real 0m1.552s
user    0m1.548s
sys     0m0.004s
$ gfortran -O3 transfer.f90 
$ time ./a.out 
 checksum = -11388423200

real    0m0.019s
user    0m0.015s
sys 0m0.004s
```
</pre>
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