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* [Bug rtl-optimization/100317] New: 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands
@ 2021-04-28 12:52 peshkoff at mail dot ru
2021-04-28 13:50 ` [Bug rtl-optimization/100317] " rguenth at gcc dot gnu.org
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: peshkoff at mail dot ru @ 2021-04-28 12:52 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100317
Bug ID: 100317
Summary: 64-bit integer compare gives wrong result when
MIN_INT64 is one of the operands
Product: gcc
Version: 9.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: peshkoff at mail dot ru
Target Milestone: ---
Created attachment 50701
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50701&action=edit
Test demonstrating comparison bug
A problem happens in trivial function comparing absolute values of 64-bit
integers. If first operand is minimum int64 value (it's absolute value is
bigger than any 64-bit number) function returns wrong value (-1) when compiled
with -O2 or higher.
Attached example demonstrates that bug - compile it with or without -O2 and get
different results. That behavior can be "fixed" using hack under #ifdef
COMPARE_BUG_FIX, but correct comparison result is desired. I've set version in
the tracker to 9.3 - this is last version I've used to check, but versions 6.4,
6.5 and 8.3 are also affected.
^ permalink raw reply [flat|nested] 7+ messages in thread* [Bug rtl-optimization/100317] 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands 2021-04-28 12:52 [Bug rtl-optimization/100317] New: 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands peshkoff at mail dot ru @ 2021-04-28 13:50 ` rguenth at gcc dot gnu.org 2021-04-28 13:58 ` peshkoff at mail dot ru ` (4 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: rguenth at gcc dot gnu.org @ 2021-04-28 13:50 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100317 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Known to work| |10.3.0, 9.3.1 Known to fail| |8.4.1 Status|UNCONFIRMED |NEW Last reconfirmed| |2021-04-28 Ever confirmed|0 |1 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- Works with GCC 10 and on the top of the GCC 9 branch so probably a duplicate. Confirmed on the GCC 8 branch. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug rtl-optimization/100317] 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands 2021-04-28 12:52 [Bug rtl-optimization/100317] New: 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands peshkoff at mail dot ru 2021-04-28 13:50 ` [Bug rtl-optimization/100317] " rguenth at gcc dot gnu.org @ 2021-04-28 13:58 ` peshkoff at mail dot ru 2021-04-28 14:23 ` jakub at gcc dot gnu.org ` (3 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: peshkoff at mail dot ru @ 2021-04-28 13:58 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100317 Alex Peshkoff <peshkoff at mail dot ru> changed: What |Removed |Added ---------------------------------------------------------------------------- Known to work| |10.2.0 --- Comment #2 from Alex Peshkoff <peshkoff at mail dot ru> --- Checked on 10.2.0 and confirm - it works. I've searched for it on the tracker but could not find duplicate. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug rtl-optimization/100317] 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands 2021-04-28 12:52 [Bug rtl-optimization/100317] New: 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands peshkoff at mail dot ru 2021-04-28 13:50 ` [Bug rtl-optimization/100317] " rguenth at gcc dot gnu.org 2021-04-28 13:58 ` peshkoff at mail dot ru @ 2021-04-28 14:23 ` jakub at gcc dot gnu.org 2021-04-28 14:24 ` jakub at gcc dot gnu.org ` (2 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: jakub at gcc dot gnu.org @ 2021-04-28 14:23 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100317 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- PR95810 ? ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug rtl-optimization/100317] 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands 2021-04-28 12:52 [Bug rtl-optimization/100317] New: 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands peshkoff at mail dot ru ` (2 preceding siblings ...) 2021-04-28 14:23 ` jakub at gcc dot gnu.org @ 2021-04-28 14:24 ` jakub at gcc dot gnu.org 2021-04-28 17:57 ` [Bug rtl-optimization/100317] [8 only] " pinskia at gcc dot gnu.org 2021-05-14 14:05 ` jakub at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: jakub at gcc dot gnu.org @ 2021-04-28 14:24 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100317 --- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- An the reason it hasn't been backported to 8 branch is that ABSU_EXPR doesn't exist there. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug rtl-optimization/100317] [8 only] 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands 2021-04-28 12:52 [Bug rtl-optimization/100317] New: 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands peshkoff at mail dot ru ` (3 preceding siblings ...) 2021-04-28 14:24 ` jakub at gcc dot gnu.org @ 2021-04-28 17:57 ` pinskia at gcc dot gnu.org 2021-05-14 14:05 ` jakub at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-04-28 17:57 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100317 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |8.5 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug rtl-optimization/100317] [8 only] 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands 2021-04-28 12:52 [Bug rtl-optimization/100317] New: 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands peshkoff at mail dot ru ` (4 preceding siblings ...) 2021-04-28 17:57 ` [Bug rtl-optimization/100317] [8 only] " pinskia at gcc dot gnu.org @ 2021-05-14 14:05 ` jakub at gcc dot gnu.org 5 siblings, 0 replies; 7+ messages in thread From: jakub at gcc dot gnu.org @ 2021-05-14 14:05 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100317 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED Target Milestone|8.5 |9.4 --- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- The GCC 8 branch is being closed, fixed in GCC 9.4. ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-05-14 14:05 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-04-28 12:52 [Bug rtl-optimization/100317] New: 64-bit integer compare gives wrong result when MIN_INT64 is one of the operands peshkoff at mail dot ru 2021-04-28 13:50 ` [Bug rtl-optimization/100317] " rguenth at gcc dot gnu.org 2021-04-28 13:58 ` peshkoff at mail dot ru 2021-04-28 14:23 ` jakub at gcc dot gnu.org 2021-04-28 14:24 ` jakub at gcc dot gnu.org 2021-04-28 17:57 ` [Bug rtl-optimization/100317] [8 only] " pinskia at gcc dot gnu.org 2021-05-14 14:05 ` jakub at gcc dot gnu.org
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