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* [Bug tree-optimization/115011] New: [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; @ 2024-05-09 12:59 652023330028 at smail dot nju.edu.cn 2024-05-09 14:27 ` [Bug tree-optimization/115011] " hjl.tools at gmail dot com ` (4 more replies) 0 siblings, 5 replies; 6+ messages in thread From: 652023330028 at smail dot nju.edu.cn @ 2024-05-09 12:59 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115011 Bug ID: 115011 Summary: [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; Product: gcc Version: 15.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: 652023330028 at smail dot nju.edu.cn Target Milestone: --- Hello, we noticed that the code below can be optimized as stated in the title, but gcc -O3 seems to have missed it. Reduced code: https://godbolt.org/z/xE6GEEn7j bool x; bool fn3(unsigned long long int f) { bool t = (0 >= f) + x; return f ? 1: t; } GCC -O3: fn3(unsigned long long): movzx eax, BYTE PTR x[rip] cmp rdi, 1 adc eax, 0 test eax, eax setne al test rdi, rdi setne dl or eax, edx ret Expected code (GCC-13.2): fn3(unsigned long long): mov eax, 1 ret Thank you very much for your time and effort! We look forward to hearing from you. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/115011] [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 2024-05-09 12:59 [Bug tree-optimization/115011] New: [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 652023330028 at smail dot nju.edu.cn @ 2024-05-09 14:27 ` hjl.tools at gmail dot com 2024-05-09 14:28 ` pinskia at gcc dot gnu.org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: hjl.tools at gmail dot com @ 2024-05-09 14:27 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115011 H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |pinskia at gcc dot gnu.org Target Milestone|--- |14.2 Status|UNCONFIRMED |NEW Last reconfirmed| |2024-05-09 Ever confirmed|0 |1 --- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> --- It is caused by r14-1597. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/115011] [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 2024-05-09 12:59 [Bug tree-optimization/115011] New: [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 652023330028 at smail dot nju.edu.cn 2024-05-09 14:27 ` [Bug tree-optimization/115011] " hjl.tools at gmail dot com @ 2024-05-09 14:28 ` pinskia at gcc dot gnu.org 2024-05-09 14:50 ` pinskia at gcc dot gnu.org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-05-09 14:28 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115011 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed|2024-05-09 00:00:00 | Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot gnu.org --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. this was "exposed/caused" by my r14-3486-gd9a0d692ffc695 . We miss this in previous releases too (LLVM is only able to optimize it for LLVM 18+): ``` bool x; bool fn3(unsigned long long int f) { bool t = (0 >= f) + x; bool t1 = t | (f != 0); return t1; } ``` I will look into this in a few weeks since I suspect it is a minor regression. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/115011] [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 2024-05-09 12:59 [Bug tree-optimization/115011] New: [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 652023330028 at smail dot nju.edu.cn 2024-05-09 14:27 ` [Bug tree-optimization/115011] " hjl.tools at gmail dot com 2024-05-09 14:28 ` pinskia at gcc dot gnu.org @ 2024-05-09 14:50 ` pinskia at gcc dot gnu.org 2024-05-09 14:50 ` pinskia at gcc dot gnu.org 2024-05-10 12:27 ` rguenth at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-05-09 14:50 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115011 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Depends on| |104292 --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- The easiest way to fix this is to optimize t_12 in: ``` _1 = f_10(D) == 0; _2 = (int) _1; //[0,1] x.0_3 = x; _4 = (int) x.0_3; //[0,1] _5 = _2 + _4; t_12 = _5 != 0; _7 = f_10(D) != 0; _14 = _7 | t_12; ``` Into: `` x.0_3 = x; _1 = f_10(D) == 0; t_12 = _1 | x.0_3; // <-- this _7 = f_10(D) != 0; _14 = _7 | t_12; ``` Which then will be optimized into true as _1 and _7 are opposites. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104292 [Bug 104292] (bool)(bool0 + bool1) should be simplified into bool0 | bool1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/115011] [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 2024-05-09 12:59 [Bug tree-optimization/115011] New: [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 652023330028 at smail dot nju.edu.cn ` (2 preceding siblings ...) 2024-05-09 14:50 ` pinskia at gcc dot gnu.org @ 2024-05-09 14:50 ` pinskia at gcc dot gnu.org 2024-05-10 12:27 ` rguenth at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-05-09 14:50 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115011 --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- So depends on PR 104292. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/115011] [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 2024-05-09 12:59 [Bug tree-optimization/115011] New: [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 652023330028 at smail dot nju.edu.cn ` (3 preceding siblings ...) 2024-05-09 14:50 ` pinskia at gcc dot gnu.org @ 2024-05-10 12:27 ` rguenth at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu.org @ 2024-05-10 12:27 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115011 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P3 |P2 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-05-10 12:27 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2024-05-09 12:59 [Bug tree-optimization/115011] New: [14/15 Regression] Missed optimization: (bool) (f ? 1: t) ==> 1 when bool t = (0 >= f) + x; 652023330028 at smail dot nju.edu.cn 2024-05-09 14:27 ` [Bug tree-optimization/115011] " hjl.tools at gmail dot com 2024-05-09 14:28 ` pinskia at gcc dot gnu.org 2024-05-09 14:50 ` pinskia at gcc dot gnu.org 2024-05-09 14:50 ` pinskia at gcc dot gnu.org 2024-05-10 12:27 ` rguenth at gcc dot gnu.org
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