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* [Bug middle-end/23412] New: [data deps] Overflow problem in Omega
@ 2005-08-15 23:08 sebastian dot pop at cri dot ensmp dot fr
2005-08-15 23:11 ` [Bug middle-end/23412] " sebastian dot pop at cri dot ensmp dot fr
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: sebastian dot pop at cri dot ensmp dot fr @ 2005-08-15 23:08 UTC (permalink / raw)
To: gcc-bugs
This pattern shows something strange in the results of Omega.
Looking at the step of array accesses it seems like Omega has
just no mechanism to handle -1 evolutions i.e. 0ffffffff in
unsigned with modulo arithmetics. This occurs in
gcc/gcc/real.c during bootstrap on amd64-linux.
Dist vectors from the first dependence analyzer:
1 1
Omega dist vectors are not the same:
-1 0
Data dependence relation is:
(Data Dep:
access_fn_A: {1, +, 4294967295}_5
access_fn_B: {2, +, 4294967295}_5
(subscript
iterations_that_access_an_element_twice_in_A: {0, +, 1}_1
last_conflict: 1
iterations_that_access_an_element_twice_in_B: {1, +, 1}_1
last_conflict: 1
(Subscript distance: 1
)
)
distance_vect: -1 0
direction_vect: - =
)
--
Summary: [data deps] Overflow problem in Omega
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: sebastian dot pop at cri dot ensmp dot fr
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23412
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug middle-end/23412] [data deps] Overflow problem in Omega 2005-08-15 23:08 [Bug middle-end/23412] New: [data deps] Overflow problem in Omega sebastian dot pop at cri dot ensmp dot fr @ 2005-08-15 23:11 ` sebastian dot pop at cri dot ensmp dot fr 2005-08-15 23:31 ` sebastian dot pop at cri dot ensmp dot fr 2005-08-17 12:24 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 5+ messages in thread From: sebastian dot pop at cri dot ensmp dot fr @ 2005-08-15 23:11 UTC (permalink / raw) To: gcc-bugs -- What |Removed |Added ---------------------------------------------------------------------------- OtherBugsDependingO| |23409 nThis| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23412 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug middle-end/23412] [data deps] Overflow problem in Omega 2005-08-15 23:08 [Bug middle-end/23412] New: [data deps] Overflow problem in Omega sebastian dot pop at cri dot ensmp dot fr 2005-08-15 23:11 ` [Bug middle-end/23412] " sebastian dot pop at cri dot ensmp dot fr @ 2005-08-15 23:31 ` sebastian dot pop at cri dot ensmp dot fr 2005-08-17 12:24 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 5+ messages in thread From: sebastian dot pop at cri dot ensmp dot fr @ 2005-08-15 23:31 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From sebastian dot pop at cri dot ensmp dot fr 2005-08-15 23:16 ------- This one is also probably an overflow in Omega, but the dependence problem looks pretty simple... This occurs in gcc/gcc/omega.c on amd64-linux. Dist vectors from the first dependence analyzer: 1 1 0 Omega dist vectors are not the same: 0 10922 10922 Data dependence relation is: (Data Dep: access_fn_A: {1, +, 1}_7 access_fn_B: {1, +, 1}_7 (subscript iterations_that_access_an_element_twice_in_A: 0 last_conflict: scev_not_known; iterations_that_access_an_element_twice_in_B: 0 last_conflict: scev_not_known; (Subscript distance: 0 ) ) distance_vect: 0 10922 10922 direction_vect: = + + ) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23412 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug middle-end/23412] [data deps] Overflow problem in Omega 2005-08-15 23:08 [Bug middle-end/23412] New: [data deps] Overflow problem in Omega sebastian dot pop at cri dot ensmp dot fr 2005-08-15 23:11 ` [Bug middle-end/23412] " sebastian dot pop at cri dot ensmp dot fr 2005-08-15 23:31 ` sebastian dot pop at cri dot ensmp dot fr @ 2005-08-17 12:24 ` pinskia at gcc dot gnu dot org 2 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2005-08-17 12:24 UTC (permalink / raw) To: gcc-bugs ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-08-17 12:23 ------- Confirmed. -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Last reconfirmed|0000-00-00 00:00:00 |2005-08-17 12:23:44 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23412 ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <bug-23412-9369@http.gcc.gnu.org/bugzilla/>]
* [Bug middle-end/23412] [data deps] Overflow problem in Omega [not found] <bug-23412-9369@http.gcc.gnu.org/bugzilla/> @ 2006-03-29 20:40 ` sebastian dot pop at cri dot ensmp dot fr 0 siblings, 0 replies; 5+ messages in thread From: sebastian dot pop at cri dot ensmp dot fr @ 2006-03-29 20:40 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from sebastian dot pop at cri dot ensmp dot fr 2006-03-29 20:40 ------- Fixed on autovect. -- sebastian dot pop at cri dot ensmp dot fr changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23412 ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2006-03-29 20:40 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2005-08-15 23:08 [Bug middle-end/23412] New: [data deps] Overflow problem in Omega sebastian dot pop at cri dot ensmp dot fr
2005-08-15 23:11 ` [Bug middle-end/23412] " sebastian dot pop at cri dot ensmp dot fr
2005-08-15 23:31 ` sebastian dot pop at cri dot ensmp dot fr
2005-08-17 12:24 ` pinskia at gcc dot gnu dot org
[not found] <bug-23412-9369@http.gcc.gnu.org/bugzilla/>
2006-03-29 20:40 ` sebastian dot pop at cri dot ensmp dot fr
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