Re: [PATCH][fortran] Make sincos, cexpi and cbrt available

[Tobias Burnus <burnus at net-b dot de>]

Hi all,

Richard Guenther wrote:
> This makes said functions available from the fortran frontend for
> use by the middle-end conditional on TARGET_C99_FUNCTIONS and 
> TARGET_GNU_SINCOS.
>
> Bootstrap and regtest in progress.
>   

I applied the patch (with the change TARGET_GNU_SINCOS ->
TARGET_HAS_SINCOS), bootstapped (with manually running symbol.c without
-Werror) and did a regression test on x86_64-unknown-linux-gnu (alias
openSUSE Factory), which gave no errors.

As all? needed parts of the middle end are also checked in,
http://gcc.gnu.org/ml/gcc-cvs/2007-01/msg00657.html  (adds
TARGET_HAS_SINCOS)
http://gcc.gnu.org/ml/gcc-cvs/2007-01/msg00658.html
this patch only depends on a Fortran maintainer's review.


> 2007-01-17  Richard Guenther  <rguenther@suse.de>
>
> 	* f95-lang.c (gfc_init_builtin_functions): Provide cbrt and
> 	cexpi builtins if we have TARGET_C99_FUNCTIONS.  Provide
> 	sincos builtins if the target has sincos.
>   
Shouldn't one add    PR fortran/30233  ?

Now, as proud owner of sincos, I tried to optimize a simple program (cf.
PR 30038); however, it does not use sincos(). Any ideas what goes wrong
here? [Same with Polyhedron's fatigue: No sincos!]

(Side note: For fatigue, the unmodified [and also the modified] gfortran
which uses sinf/cosf takes 19.7s, ifort which uses sincos needs 11.8s
and sunf95 needs only 8.4s and uses sin/cos. With gfortran I got once a
>20% speedup with sincos [cf. PR 30038, comment 17].)

(Side note 2: Using r**(1./3.) => cbrtf() works.)

Tobias

PS: Big thanks to Richard for his sincos work!

----------------------------------------
integer :: i, j
volatile :: j = 1
real :: r, s(10000),c(10000)
do i = 1, 10000
  r = real(i)/1000.0
  s(i) = sin(r)
  c(i) = cos(r)
end do
print *, s(j),c(j)
end
----------------------------------------

If I run now:
gfortran -O3 -ftree-vectorize -ftree-vectorizer-verbose=6 -funroll-loops
-ffast-math -msse3 x.f90
x.f90:7: note: not vectorized: unsupported use in stmt.
x.f90:1: note: vectorized 0 loops in function.

Looking at x.f90.103t.vrp2 shows:

<L0>:;
  D.1460_61 = (<unnamed type>) ivtmp.36_59;
  D.1461_64 = D.1460_61 + 2;
  i_66 = (int4) D.1461_64;
  i_1 = i_66;
  D.1396_3 = (real4) i_1;
  r_4 = D.1396_3 * 1.000000047497451305389404296875e-3;
  D.1399_7 = __builtin_sinf (r_4);
  D.1462_56 = (<unnamed type>) ivtmp.36_59;
  MEM[symbol: s, index: D.1462_56, step: 4, offset: 4] = D.1399_7;
  D.1400_10 = __builtin_cosf (r_4);
  D.1463_55 = (<unnamed type>) ivtmp.36_59;
  MEM[symbol: c, index: D.1463_55, step: 4, offset: 4] = D.1400_10;
  ivtmp.36_60 = ivtmp.36_59 + 1;
  if (ivtmp.36_60 == 9999) goto <L4>; else goto <L0>;