[Bug tree-optimization/21643] GCC fails to merge ranges in comparison.

[rivasgilbie121 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=21643

Gilbie Rivas  changed:

   What|Removed |Added

 CC||rivasgilbie121 at gmail dot com

--- Comment #8 from Gilbie Rivas  ---
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[Bug tree-optimization/21643] GCC fails to merge ranges in comparison.

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21643



--- Comment #6 from Jakub Jelinek jakub at gcc dot gnu.org 2012-10-31 
08:45:35 UTC ---

Author: jakub

Date: Wed Oct 31 08:45:27 2012

New Revision: 193028



URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=193028

Log:

PR tree-optimization/19105

PR tree-optimization/21643

PR tree-optimization/46309

* tree-ssa-reassoc.c (init_range_entry): Add STMT argument

and use it if EXP is NULL.

(update_range_test): Handle OPCODE equal to ERROR_MARK

and oe-op NULL.

(optimize_range_tests): Likewise.

(final_range_test_p, suitable_cond_bb, no_side_effect_bb, get_ops,

maybe_optimize_range_tests): New functions.

(reassociate_bb): Call maybe_optimize_range_tests if last

stmt of bb is GIMPLE_COND that hasn't been visited yet.



* gcc.dg/pr19105.c: New test.

* gcc.dg/pr21643.c: New test.

* gcc.dg/pr46309-2.c: New test.

* gcc.c-torture/execute/pr46309.c: New test.



Added:

trunk/gcc/testsuite/gcc.c-torture/execute/pr46309.c

trunk/gcc/testsuite/gcc.dg/pr19105.c

trunk/gcc/testsuite/gcc.dg/pr21643.c

trunk/gcc/testsuite/gcc.dg/pr46309-2.c

Modified:

trunk/gcc/ChangeLog

trunk/gcc/testsuite/ChangeLog

trunk/gcc/tree-ssa-reassoc.c

[Bug tree-optimization/21643] GCC fails to merge ranges in comparison.

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21643



Jakub Jelinek jakub at gcc dot gnu.org changed:



   What|Removed |Added



 Status|NEW |RESOLVED

 CC||jakub at gcc dot gnu.org

 Resolution||FIXED

   Target Milestone|--- |4.8.0



--- Comment #7 from Jakub Jelinek jakub at gcc dot gnu.org 2012-10-31 
08:51:45 UTC ---

Fixed for 4.8+.

[Bug tree-optimization/21643] GCC fails to merge ranges in comparison.

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21643

Andrew Pinski pinskia at gcc dot gnu.org changed:

   What|Removed |Added

 Depends on||46309

--- Comment #5 from Andrew Pinski pinskia at gcc dot gnu.org 2012-02-08 
20:53:57 UTC ---
Related to PR 46309.

[Bug tree-optimization/21643] GCC fails to merge ranges in comparison.

[pinskia at gcc dot gnu dot org]

--- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-18 
12:38 ---
Confirmed.

-- 
   What|Removed |Added

 CC||pinskia at gcc dot gnu dot
   ||org
   Severity|normal  |enhancement
 Status|UNCONFIRMED |NEW
  Component|rtl-optimization|tree-optimization
 Ever Confirmed||1
   Keywords||missed-optimization
   Last reconfirmed|-00-00 00:00:00 |2005-05-18 12:38:44
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21643

[Bug tree-optimization/21643] GCC fails to merge ranges in comparison.

[trt at acm dot org]

--- Additional Comments From trt at acm dot org  2005-05-18 17:21 ---
This is because fold-const.c only does ad-hoc re-association.
Here is an example for fold_truthop (approx line 8805)

  /* Check for the possibility of merging component references.  If our
 lhs is another similar operation, try to merge its rhs with our
 rhs.  Then try to merge our lhs and rhs.  */
  if (TREE_CODE (arg0) == code
   0 != (tem = fold_truthop (code, type,
   TREE_OPERAND (arg0, 1), arg1)))
return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);

A similar hack could be done for fold_range_test.

(I wrote a helper fold_assoc (f, x, code, type, op1, op2) that does this in a
more general way, but it in turn needed `find_assoc_p' and `commutes_p'
functions, and handling EXPR_MINUS was onerous.  It might be too slow for
general use.  Basically, it needs a fast way to check for common subexpressions
to avoid pointless recursions.)

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21643

[Bug tree-optimization/21643] GCC fails to merge ranges in comparison.

[trt at acm dot org]

--- Additional Comments From trt at acm dot org  2005-05-18 17:28 ---
Here is a equivalent case that gcc also misses (but beyond scope of
fold-const.c). By the way, since there is a missing final return, can't gcc just
simplify all three functions into return 1; :-)

int fish3(unsigned char c)
{
if (c =='') return 1;
if (c == 0x20) return 1;
if (c  0x20) return 1;
}


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21643