[Bug tree-optimization/21289] New: A numeric range is spoiled by a symblic one in VRP

[Bug tree-optimization/21289] New: A numeric range is spoiled by a symblic one in VRP

[kazu at cs dot umass dot edu]

Consider

int
foo (int a, int b)
{
  if (a == 1)
    if (a < b)
      if (a == 1)
	return 1;

  return 0;
}

VRP does not remove the third "if" even though 'a' is known to be 1.

This is because the symbolic range obtained from the second "if"
spoils the numeric range [1, 1] obtained from the first "if".

extract_range_from_assert tries to refine a range from an ASSERT_EXPR
if there is another range previously available, but in this case,
VRP cannot prove that [1,1] and [-INF, b-1] intersects,
it does not refine a range.

-- 
           Summary: A numeric range is spoiled by a symblic one in VRP
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kazu at cs dot umass dot edu
                CC: dnovillo at redhat dot com,gcc-bugs at gcc dot gnu dot
                    org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21289

[Bug tree-optimization/21289] A numeric range is spoiled by a symblic one in VRP

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-04-29 19:28 -------
Confirmed, to me if the range of a variable is not really a range but one value, it should always merge.  I 
think that is safe.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-04-29 19:28:39
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21289

[Bug tree-optimization/21289] A numeric range is spoiled by a symblic one in VRP

[dberlin at gcc dot gnu dot org]

------- Additional Comments From dberlin at gcc dot gnu dot org  2005-04-29 20:37 -------
(In reply to comment #1)
> Confirmed, to me if the range of a variable is not really a range but one
value, it should always merge.  I 
> think that is safe.

It's only safe if both old ranges dominate the new range, as it does here.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21289

[Bug tree-optimization/21289] A numeric range is spoiled by a symblic one in VRP

[kazu at cs dot umass dot edu]

------- Additional Comments From kazu at cs dot umass dot edu  2005-05-14 19:40 -------
Another case of a numeric value range spoiled by a symbolic one:

int
foo (int a, int b)
{
  if (a == 0)
    return 0;

  if (a == b)
    if (a == 0)
      return 123;

  return 456;
}

Reduced from c-common.c.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21289

[Bug tree-optimization/21289] A numeric range is spoiled by a symblic one in VRP

[dnovillo at redhat dot com]

------- Additional Comments From dnovillo at redhat dot com  2005-05-14 20:00 -------
Subject: Re:  A numeric range is spoiled by a symblic one in VRP

On Sat, May 14, 2005 at 07:40:04PM -0000, kazu at cs dot umass dot edu wrote:
> 
> ------- Additional Comments From kazu at cs dot umass dot edu  2005-05-14 19:40 -------
> Another case of a numeric value range spoiled by a symbolic one:
> 
Fixed with my current changes to VRP.


Diego.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21289

[Bug tree-optimization/21289] A numeric range is spoiled by a symblic one in VRP

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-06-02 02:57 -------
Subject: Bug 21289

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	dnovillo@gcc.gnu.org	2005-06-02 02:57:15

Modified files:
	gcc            : ChangeLog fold-const.c tree-flow.h 
	                 tree-ssa-ccp.c tree-ssa-copy.c 
	                 tree-ssa-propagate.c tree-ssa-propagate.h 
	                 tree-vrp.c tree.h 
	gcc/testsuite  : ChangeLog 
	gcc/testsuite/gcc.dg/tree-ssa: pr14841.c pr21658.c 
Added files:
	gcc/testsuite/gcc.dg/tree-ssa: pr14341.c pr20701.c pr21029.c 
	                               pr21086.c pr21090.c pr21332.c 
	                               pr21458.c vrp01.c vrp02.c vrp03.c 
	                               vrp04.c vrp05.c vrp06.c vrp07.c 
	                               vrp08.c vrp09.c vrp10.c vrp11.c 
	                               vrp12.c vrp13.c 

Log message:
	2005-06-01  Diego Novillo  <dnovillo@redhat.com>
	
	PR 14341, PR 21332, PR 20701, PR 21029, PR 21086, PR 21090
	PR 21289, PR 21348, PR 21367, PR 21368, PR 21458.
	* fold-const.c (invert_tree_comparison): Make extern.
	* tree-flow.h (enum value_range_type): Move to tree-ssa-propagate.
	(struct value_range_def): Limewise.
	(get_value_range): Remove.
	(dump_value_range): Remove.
	(dump_all_value_ranges): Remove.
	(debug_all_value_ranges): Remove.
	(vrp_evaluate_conditional): Declare.
	* tree-ssa-propagate.c (struct prop_stats_d): Add field
	num_pred_folded.
	(substitute_and_fold): Add argument use_ranges_p.
	Update all callers.
	If use_ranges_p is true, call fold_predicate_in to fold
	predicates using range information.
	Ignore ASSERT_EXPRs.
	Change debugging output to only show statements that have been
	folded.
	(replace_phi_args_in): Move debugging output code from
	substitute and fold.
	(fold_predicate_in): New local function.
	* tree-ssa-propagate.h (enum value_range_type): Move from
	tree-flow.h.
	(struct value_range_d): Likewise.
	Add field 'equiv'.
	(value_range_t): Rename from value_range.
	* tree-vrp.c (found_in_subgraph): Rename from found.
	(get_opposite_operand): Remove.
	(struct assert_locus_d): Declare.
	(assert_locus_t): Declare.
	(need_assert_for): Declare.
	(asserts_for): Declare.
	(blocks_visited): Declare.
	(vr_value): Declare.
	(set_value_range): Add argument 'equiv'.
	Don't drop to VARYING ranges that cover all values in the
	type.
	Make deep copy of equivalence set 'equiv'.
	(copy_value_range): New local function.
	(set_value_range_to_undefined): New local function.
	(compare_values): Return -2 if either value has overflowed.
	(range_includes_zero_p): New local function.
	(extract_range_from_assert): Flip the predicate code if the
	name being asserted is on the RHS of the predicate.
	Avoid creating unnecessary symbolic ranges if the comparison
	includes another name with a known numeric range.
	Update the equivalnce set of the new range when asserting
	EQ_EXPR predicates.
	(extract_range_from_ssa_name): Update the equivalence set of
	the new range with VAR.
	(extract_range_from_binary_expr): Also handle TRUTH_*_EXPR.
	If -fwrapv is used, set the resulting range to VARYING if the
	operation overflows.  Otherwise, use TYPE_MIN_VALUE and
	TYPE_MAX_VALUE to represent -INF and +INF.
	Fix handling of *_DIV_EXPR.
	(extract_range_from_unary_expr): Handle MINUS_EXPR and
	ABS_EXPR properly by switching the range around if necessary.
	(extract_range_from_comparison): New local function.
	(extract_range_from_expr): Call it.
	(adjust_range_with_scev): Do not adjust the range if using
	wrapping arithmetic (-fwrapv).
	(dump_value_range): Also show equivalence set.
	Show -INF and +INF for TYPE_MIN_VALUE and TYPE_MAX_VALUE.
	(build_assert_expr_for): Also build ASSERT_EXPR for EQ_EXPR.
	(infer_value_range): Change return value to bool.
	Add arguments 'comp_code_p' and 'val_p'.
	Do not attempt to infer ranges from statements that may throw.
	Store the comparison code in comp_code_p.
	Store the other operand to be used in the predicate in val_p.
	(dump_asserts_for): New.
	(debug_asserts_for): New.
	(dump_all_asserts): New.
	(debug_all_asserts): New.
	(register_new_assert_for): New.
	(register_edge_assert_for): New.
	(find_conditional_asserts): New.
	(find_assert_locations): New.
	(process_assert_insertions_for): New.
	(process_assert_insertions): New.
	(insert_range_assertions): Initialize found_in_subgraph,
	blocks_visited, need_assert_for and asserts_for.
	Call find_assert_locations and process_assert_insertions.
	(remove_range_assertions): Add more documentation.
	(vrp_initialize): Change return type to void.
	Do not try to guess if running VRP is worth it.
	(compare_name_with_value): New.
	(compare_names): New.
	(vrp_evaluate_conditional): Add argument 'use_equiv_p'.  If
	use_equiv_p is true, call compare_names and
	compare_name_with_value to compare all the ranges for every
	name in the equivalence set of the predicate operands.
	Update all callers.
	(vrp_meet): Try harder not to derive a VARYING range.
	If two values meet, the resulting equivalence set is the
	intersection of the two equivalence sets.
	(vrp_visit_phi_node): Call copy_value_range to get the current
	range information of the LHS.
	(vrp_finalize): Create a value vector representing all the
	names that ended up with exactly one value in their range.
	Call substitute_and_fold.
	(execute_vrp): Document equivalence sets in ranges.
	* tree.h (SSA_NAME_VALUE_RANGE): Remove.
	(struct tree_ssa_name): Remove field value_range.
	(invert_tree_comparison): Declare.
	
	testsuite/ChangeLog
	
	2005-06-01  Diego Novillo  <dnovillo@redhat.com>
	
	PR 14341, PR 21332, PR 20701, PR 21086, PR 21090
	PR 21289, PR 21348, PR 21367, PR 21368, PR 21458.
	* gcc.dg/tree-ssa/pr14341.c: New test.
	* gcc.dg/tree-ssa/pr14841.c: New test.
	* gcc.dg/tree-ssa/pr20701.c: New test.
	* gcc.dg/tree-ssa/pr21086.c: New test.
	* gcc.dg/tree-ssa/pr21090.c: New test.
	* gcc.dg/tree-ssa/pr21332.c: New test.
	* gcc.dg/tree-ssa/pr21458.c: New test.
	* gcc.dg/tree-ssa/pr21658.c: New test.
	* gcc.dg/tree-ssa/vrp01.c: New test.
	* gcc.dg/tree-ssa/vrp02.c: New test.
	* gcc.dg/tree-ssa/vrp03.c: New test.
	* gcc.dg/tree-ssa/vrp04.c: New test.
	* gcc.dg/tree-ssa/vrp05.c: New test.
	* gcc.dg/tree-ssa/vrp06.c: New test.
	* gcc.dg/tree-ssa/vrp07.c: New test.
	* gcc.dg/tree-ssa/vrp08.c: New test.
	* gcc.dg/tree-ssa/vrp09.c: New test.
	* gcc.dg/tree-ssa/vrp10.c: New test.
	* gcc.dg/tree-ssa/vrp11.c: New test.
	* gcc.dg/tree-ssa/vrp12.c: New test.
	* gcc.dg/tree-ssa/vrp13.c: New test.
	
	2005-06-01  Alexandre Oliva  <aoliva@redhat.com>
	
	PR 21029
	* gcc.dg/tree-ssa/pr21029.c: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.8989&r2=2.8990
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/fold-const.c.diff?cvsroot=gcc&r1=1.589&r2=1.590
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-flow.h.diff?cvsroot=gcc&r1=2.114&r2=2.115
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-ccp.c.diff?cvsroot=gcc&r1=2.77&r2=2.78
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-copy.c.diff?cvsroot=gcc&r1=2.32&r2=2.33
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-propagate.c.diff?cvsroot=gcc&r1=2.22&r2=2.23
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-propagate.h.diff?cvsroot=gcc&r1=2.3&r2=2.4
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-vrp.c.diff?cvsroot=gcc&r1=2.18&r2=2.19
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree.h.diff?cvsroot=gcc&r1=1.732&r2=1.733
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5574&r2=1.5575
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr14341.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr20701.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr21029.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr21086.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr21090.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr21332.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr21458.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp01.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp02.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp03.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp04.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp05.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp06.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp07.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp08.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp09.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp10.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp11.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp12.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/vrp13.c.diff?cvsroot=gcc&r1=NONE&r2=1.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr14841.c.diff?cvsroot=gcc&r1=1.1&r2=1.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/tree-ssa/pr21658.c.diff?cvsroot=gcc&r1=1.1&r2=1.2



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21289

[Bug tree-optimization/21289] A numeric range is spoiled by a symblic one in VRP

[dnovillo at gcc dot gnu dot org]

------- Additional Comments From dnovillo at gcc dot gnu dot org  2005-06-02 03:08 -------

Fixed.  http://gcc.gnu.org/ml/gcc-patches/2005-06/msg00127.html

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21289

[Bug tree-optimization/21289] A numeric range is spoiled by a symblic one in VRP

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21289