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* [Bug tree-optimization/112392] New: `a == nonnegative ? a : abs<a>` -> abs<a>
@ 2023-11-05 5:56 pinskia at gcc dot gnu.org
2023-11-05 5:58 ` [Bug tree-optimization/112392] " pinskia at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-11-05 5:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112392
Bug ID: 112392
Summary: `a == nonnegative ? a : abs<a>` -> abs<a>
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, unsigned char b)
{
int absb = b;
if (a == absb) return absb;
return a > 0 ? a : -a;
}
```
This should just be turned into
`return ABS_EXPR<a>;`
as we know that if a was a nonnegative value, then taking the ABS of that is
the same as a.
So something like:
```
(for cmp (eq gt ge)
(simplify
(cond (cmp:c @0 tree_expr_nonnegative_p@1) @0 (abs@3 @0))
(if (INTEGRAL_TYPE_P (type))
@3))
```
`a > nonnegative ? a : abs<a>` is also just `abs<a>` too.
There are some more improvements dealing with type changing between signed and
unsigned but this is the first step.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/112392] `a == nonnegative ? a : abs<a>` -> abs<a>
2023-11-05 5:56 [Bug tree-optimization/112392] New: `a == nonnegative ? a : abs<a>` -> abs<a> pinskia at gcc dot gnu.org
@ 2023-11-05 5:58 ` pinskia at gcc dot gnu.org
2023-11-14 0:34 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-11-05 5:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112392
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
See Also| |https://gcc.gnu.org/bugzill
| |a/show_bug.cgi?id=111957
Last reconfirmed| |2023-11-05
Status|UNCONFIRMED |ASSIGNED
Ever confirmed|0 |1
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is related to PR 111957. For positive values this would catch it too.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/112392] `a == nonnegative ? a : abs<a>` -> abs<a>
2023-11-05 5:56 [Bug tree-optimization/112392] New: `a == nonnegative ? a : abs<a>` -> abs<a> pinskia at gcc dot gnu.org
2023-11-05 5:58 ` [Bug tree-optimization/112392] " pinskia at gcc dot gnu.org
@ 2023-11-14 0:34 ` pinskia at gcc dot gnu.org
2024-05-08 3:25 ` pinskia at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-11-14 0:34 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112392
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 56579
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56579&action=edit
More complete testcase for the ones which should be detected
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/112392] `a == nonnegative ? a : abs<a>` -> abs<a>
2023-11-05 5:56 [Bug tree-optimization/112392] New: `a == nonnegative ? a : abs<a>` -> abs<a> pinskia at gcc dot gnu.org
2023-11-05 5:58 ` [Bug tree-optimization/112392] " pinskia at gcc dot gnu.org
2023-11-14 0:34 ` pinskia at gcc dot gnu.org
@ 2024-05-08 3:25 ` pinskia at gcc dot gnu.org
2024-05-08 15:38 ` cvs-commit at gcc dot gnu.org
2024-05-08 15:39 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-05-08 3:25 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112392
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |patch
URL| |https://gcc.gnu.org/piperma
| |il/gcc-patches/2024-May/651
| |006.html
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Patch submitted:
https://gcc.gnu.org/pipermail/gcc-patches/2024-May/651006.html
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/112392] `a == nonnegative ? a : abs<a>` -> abs<a>
2023-11-05 5:56 [Bug tree-optimization/112392] New: `a == nonnegative ? a : abs<a>` -> abs<a> pinskia at gcc dot gnu.org
` (2 preceding siblings ...)
2024-05-08 3:25 ` pinskia at gcc dot gnu.org
@ 2024-05-08 15:38 ` cvs-commit at gcc dot gnu.org
2024-05-08 15:39 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2024-05-08 15:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112392
--- Comment #4 from GCC 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:5726de79e2154a16d8a045567d2cfad035f7ed19
commit r15-328-g5726de79e2154a16d8a045567d2cfad035f7ed19
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date: Mon May 6 23:53:41 2024 -0700
match: `a CMP nonnegative ? a : ABS<a>` simplified to just `ABS<a>`
[PR112392]
We can optimize `a == nonnegative ? a : ABS<a>`, `a > nonnegative ? a :
ABS<a>`
and `a >= nonnegative ? a : ABS<a>` into `ABS<a>`. This allows removal of
some extra comparison and extra conditional moves in some cases.
I don't remember where I had found though but it is simple to add so
let's add it.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
Note I have a secondary pattern for the equal case as either a or
nonnegative
could be used.
PR tree-optimization/112392
gcc/ChangeLog:
* match.pd (`x CMP nonnegative ? x : ABS<x>`): New pattern;
where CMP is ==, > and >=.
(`x CMP nonnegative@y ? y : ABS<x>`): New pattern.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/phi-opt-41.c: New test.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/112392] `a == nonnegative ? a : abs<a>` -> abs<a>
2023-11-05 5:56 [Bug tree-optimization/112392] New: `a == nonnegative ? a : abs<a>` -> abs<a> pinskia at gcc dot gnu.org
` (3 preceding siblings ...)
2024-05-08 15:38 ` cvs-commit at gcc dot gnu.org
@ 2024-05-08 15:39 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-05-08 15:39 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112392
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Target Milestone|--- |15.0
Resolution|--- |FIXED
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2023-11-05 5:56 [Bug tree-optimization/112392] New: `a == nonnegative ? a : abs<a>` -> abs<a> pinskia at gcc dot gnu.org
2023-11-05 5:58 ` [Bug tree-optimization/112392] " pinskia at gcc dot gnu.org
2023-11-14 0:34 ` pinskia at gcc dot gnu.org
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