[Bug fortran/43210] Initializer of huge static arrays should be improved

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

--- Comment #11 from Dominique d'Humieres  ---
I still see

...
_hugearray.3858:
.long   42
.long   42
.long   42
...

[Bug fortran/43210] Initializer of huge static arrays should be improved

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

--- Comment #10 from Jakub Jelinek  ---
Author: jakub
Date: Tue Feb 26 10:36:05 2019
New Revision: 269207

URL: https://gcc.gnu.org/viewcvs?rev=269207=gcc=rev
Log:
PR fortran/43210
* trans-array.c (gfc_conv_array_initializer): Use RANGE_EXPR instead
of duplicating the initializer possibly many times.

Modified:
trunk/gcc/fortran/ChangeLog
trunk/gcc/fortran/trans-array.c

[Bug fortran/43210] Initializer of huge static arrays should be improved

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

--- Comment #9 from Jakub Jelinek  ---
Created attachment 45818
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45818=edit
gcc9-pr43210.patch

Like this (untested so far).

[Bug fortran/43210] Initializer of huge static arrays should be improved

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

--- Comment #8 from Jakub Jelinek  ---
Well, I'm not convinced the #c0 transformation should be done by default, but
what should and can be done is instead of emitting {42, 42, 42, , 42}; emit
like the C or C++ FEs emit {[1..100] = 42} which is much more compile time
memory friendly, and if the user doesn't require that it is SAVEd, e.g. the
gimplifier has code to decide if having a .rodata initializer vs. initializing
by a loop is beneficial.  See PR82294 or PR87436 for the C++ counterparts.
I see a single spot with RANGE_EXPR even in the Fortran FE, so maybe it does it
already.

[Bug fortran/43210] Initializer of huge static arrays should be improved

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

--- Comment #7 from Dominique d'Humieres  ---
> This is definitely an area where improvement would be quite helpful -
> our performance there is abysmal.

Compiling the test on my laptop takes less than 3s!

[Bug fortran/43210] Initializer of huge static arrays should be improved

[tkoenig at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

Thomas Koenig  changed:

   What|Removed |Added

 Status|RESOLVED|NEW
 CC||tkoenig at gcc dot gnu.org
 Resolution|WONTFIX |---
   Severity|normal  |enhancement

--- Comment #6 from Thomas Koenig  ---
Sorry, I missed that one.

This is definitely an area where improvement would be quite helpful -
our performance there is abysmal.

Dominique, I'm all for closing bugs :-) but I think one or two
of them should stay. Just because nobody has found time, inclination
or knowledge to work on them does not mean nobody should.

[Bug fortran/43210] Initializer of huge static arrays should be improved

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

Dominique d'Humieres  changed:

   What|Removed |Added

 Status|WAITING |RESOLVED
 Resolution|--- |WONTFIX

--- Comment #5 from Dominique d'Humieres  ---
> This PR is almost ten year old. Any point to let it rot anymore?

No answer: WONTFIX.

[Bug fortran/43210] Initializer of huge static arrays should be improved

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

Dominique d'Humieres  changed:

   What|Removed |Added

 Status|NEW |WAITING

--- Comment #4 from Dominique d'Humieres  ---
This PR is almost ten year old. Any point to let it rot anymore?

[Bug fortran/43210] Initializer of huge static arrays should be improved

[pault at gcc dot gnu dot org]

--- Comment #3 from pault at gcc dot gnu dot org  2010-03-27 18:47 ---
Confirmed

Paul


-- 

pault at gcc dot gnu dot org changed:

   What|Removed |Added

 Status|UNCONFIRMED |NEW
 Ever Confirmed|0   |1
   Last reconfirmed|-00-00 00:00:00 |2010-03-27 18:47:20
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

[Bug fortran/43210] Initializer of huge static arrays should be improved

[jvdelisle at gcc dot gnu dot org]

--- Comment #2 from jvdelisle at gcc dot gnu dot org  2010-03-20 20:19 
---
See fortran-exp branch where we are working these issues.  Once the splay-tree
structure is in place we can then focus on setting a limit and not simplify
the constructor.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210

[Bug fortran/43210] Initializer of huge static arrays should be improved

[burnus at gcc dot gnu dot org]

--- Comment #1 from burnus at gcc dot gnu dot org  2010-02-28 15:02 ---
A bonus: There should be only a single logical initialized variable for all
initializers.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43210