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* [Bug tree-optimization/111679] New: `(~a) | (a ^ b)` is not simplified to `~(a & b)`
@ 2023-10-03 16:11 pinskia at gcc dot gnu.org
2023-10-03 16:11 ` [Bug tree-optimization/111679] " pinskia at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-10-03 16:11 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111679
Bug ID: 111679
Summary: `(~a) | (a ^ b)` is not simplified to `~(a & b)`
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
Assignee: pinskia at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Take:
```
int f(int a, int b)
{
return a | ((~a) ^ b);
}
int f1(int a, int b)
{
return (~a) | (a ^ b); // ~(a & b) or (~a) | (~b)
}
```
The only difference between these 2 functions is a is bitwise inversed. f is
able to be detected and simplified but not f1.
I Noticed this while working on PR 111282.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/111679] `(~a) | (a ^ b)` is not simplified to `~(a & b)`
2023-10-03 16:11 [Bug tree-optimization/111679] New: `(~a) | (a ^ b)` is not simplified to `~(a & b)` pinskia at gcc dot gnu.org
@ 2023-10-03 16:11 ` pinskia at gcc dot gnu.org
2023-10-05 4:15 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-10-03 16:11 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111679
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2023-10-03
Ever confirmed|0 |1
Status|UNCONFIRMED |ASSIGNED
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/111679] `(~a) | (a ^ b)` is not simplified to `~(a & b)`
2023-10-03 16:11 [Bug tree-optimization/111679] New: `(~a) | (a ^ b)` is not simplified to `~(a & b)` pinskia at gcc dot gnu.org
2023-10-03 16:11 ` [Bug tree-optimization/111679] " pinskia at gcc dot gnu.org
@ 2023-10-05 4:15 ` pinskia at gcc dot gnu.org
2023-10-09 21:28 ` pinskia at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-10-05 4:15 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111679
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
```
/* (~a) | (a ^ b) --> (~a) | (~b)
(which might be done into ~(a & b) depending on if ~a is not a cmp) */
(simplify
(bit_ior:c @0 (bit_xor:c @1 @2))
(with { bool wascmp; }
(if (bitwise_inverted_equal_p (@0, @1, wascmp)
&& (!wascmp || element_precision (type) == 1))
(bit_ior @0 (bit_not @2)))))
```
Still need some testcases.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/111679] `(~a) | (a ^ b)` is not simplified to `~(a & b)`
2023-10-03 16:11 [Bug tree-optimization/111679] New: `(~a) | (a ^ b)` is not simplified to `~(a & b)` pinskia at gcc dot gnu.org
2023-10-03 16:11 ` [Bug tree-optimization/111679] " pinskia at gcc dot gnu.org
2023-10-05 4:15 ` pinskia at gcc dot gnu.org
@ 2023-10-09 21:28 ` pinskia at gcc dot gnu.org
2023-10-10 17:27 ` cvs-commit at gcc dot gnu.org
2023-10-10 17:29 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-10-09 21:28 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111679
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |patch
URL| |https://gcc.gnu.org/piperma
| |il/gcc-patches/2023-October
| |/632386.html
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Patch posted:
https://gcc.gnu.org/pipermail/gcc-patches/2023-October/632386.html
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/111679] `(~a) | (a ^ b)` is not simplified to `~(a & b)`
2023-10-03 16:11 [Bug tree-optimization/111679] New: `(~a) | (a ^ b)` is not simplified to `~(a & b)` pinskia at gcc dot gnu.org
` (2 preceding siblings ...)
2023-10-09 21:28 ` pinskia at gcc dot gnu.org
@ 2023-10-10 17:27 ` cvs-commit at gcc dot gnu.org
2023-10-10 17:29 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2023-10-10 17:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111679
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>:
https://gcc.gnu.org/g:975da6fa9170c9cf1ec4a9a9d8177f8561d464d1
commit r14-4543-g975da6fa9170c9cf1ec4a9a9d8177f8561d464d1
Author: Andrew Pinski <pinskia@gmail.com>
Date: Mon Oct 9 11:07:08 2023 -0700
MATCH: [PR111679] Add alternative simplification of `a | ((~a) ^ b)`
So currently we have a simplification for `a | ~(a ^ b)` but
that does not match the case where we had originally `(~a) | (a ^ b)`
so we need to add a new pattern that matches that and uses
bitwise_inverted_equal_p
that also catches comparisons too.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/111679
gcc/ChangeLog:
* match.pd (`a | ((~a) ^ b)`): New pattern.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/bitops-5.c: New test.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/111679] `(~a) | (a ^ b)` is not simplified to `~(a & b)`
2023-10-03 16:11 [Bug tree-optimization/111679] New: `(~a) | (a ^ b)` is not simplified to `~(a & b)` pinskia at gcc dot gnu.org
` (3 preceding siblings ...)
2023-10-10 17:27 ` cvs-commit at gcc dot gnu.org
@ 2023-10-10 17:29 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-10-10 17:29 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111679
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |14.0
Status|ASSIGNED |RESOLVED
Resolution|--- |FIXED
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed.
^ permalink raw reply [flat|nested] 6+ messages in thread
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