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* [Bug tree-optimization/27109] Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else)
2006-04-11 2:04 [Bug tree-optimization/27109] New: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) pinskia at gcc dot gnu dot org
@ 2006-04-11 2:04 ` pinskia at gcc dot gnu dot org
2006-12-28 12:03 ` rguenth at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-04-11 2:04 UTC (permalink / raw)
To: gcc-bugs
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27109
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/27109] New: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else)
@ 2006-04-11 2:04 pinskia at gcc dot gnu dot org
2006-04-11 2:04 ` [Bug tree-optimization/27109] " pinskia at gcc dot gnu dot org
2006-12-28 12:03 ` rguenth at gcc dot gnu dot org
0 siblings, 2 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-04-11 2:04 UTC (permalink / raw)
To: gcc-bugs
Kinda like PR 14490 but for the -fwrapv and unsigned cases:
void bar (void);
void
foo (unsigned a)
{
if (a < 100)
return;
if (200 < a)
return;
if (a - 10 > 150)
bar ();
}
--
Summary: Simplify "a - 10 > 150" into "a > 160" when range of a
is known (in VRP or somewhere else)
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: pinskia at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27109
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/27109] Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else)
2006-04-11 2:04 [Bug tree-optimization/27109] New: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) pinskia at gcc dot gnu dot org
2006-04-11 2:04 ` [Bug tree-optimization/27109] " pinskia at gcc dot gnu dot org
@ 2006-12-28 12:03 ` rguenth at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-12-28 12:03 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from rguenth at gcc dot gnu dot org 2006-12-28 12:03 -------
Confirmed. compare_values needs to be teached to look at value ranges for
operands and decide on overflow there - but only for substitute and fold as
earlier we can have invalid intermediate value ranges.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu dot
| |org
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2006-12-28 12:03:15
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27109
^ permalink raw reply [flat|nested] 3+ messages in thread
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2006-04-11 2:04 [Bug tree-optimization/27109] New: Simplify "a - 10 > 150" into "a > 160" when range of a is known (in VRP or somewhere else) pinskia at gcc dot gnu dot org
2006-04-11 2:04 ` [Bug tree-optimization/27109] " pinskia at gcc dot gnu dot org
2006-12-28 12:03 ` rguenth at gcc dot gnu dot org
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