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* [Bug tree-optimization/112356] New: `x == MIN & x > y` is not optimized to 0 if x was casted to signed from unsigned
@ 2023-11-02 20:53 pinskia at gcc dot gnu.org
2023-11-02 20:53 ` [Bug tree-optimization/112356] " pinskia at gcc dot gnu.org
2023-11-02 21:00 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-11-02 20:53 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112356
Bug ID: 112356
Summary: `x == MIN & x > y` is not optimized to 0 if x was
casted to signed from unsigned
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:
```
#include <limits.h>
signed f2_1( unsigned x, signed y)
{
signed xs = x;
signed t = x == INT_MIN;
signed t1 = xs > y;
return t & t1;
}
```
This is not optimized to 0.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/112356] `x == MIN & x > y` is not optimized to 0 if x was casted to signed from unsigned
2023-11-02 20:53 [Bug tree-optimization/112356] New: `x == MIN & x > y` is not optimized to 0 if x was casted to signed from unsigned pinskia at gcc dot gnu.org
@ 2023-11-02 20:53 ` pinskia at gcc dot gnu.org
2023-11-02 21:00 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-11-02 20:53 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112356
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Ever confirmed|0 |1
Last reconfirmed| |2023-11-02
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/112356] `x == MIN & x > y` is not optimized to 0 if x was casted to signed from unsigned
2023-11-02 20:53 [Bug tree-optimization/112356] New: `x == MIN & x > y` is not optimized to 0 if x was casted to signed from unsigned pinskia at gcc dot gnu.org
2023-11-02 20:53 ` [Bug tree-optimization/112356] " pinskia at gcc dot gnu.org
@ 2023-11-02 21:00 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-11-02 21:00 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112356
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The problem is we can't use `(match min_value` here but rather we need to
change it from:
```
(for eqne (eq ne)
(simplify
(bit_and:c (gt:c@2 @0 @1) (eqne @0 min_value))
```
to:
```
(for eqne (eq ne)
(simplify
(bit_and:c (gt:c@2 @0 @1) (eqne @3 uniform_integer_cst_p@2))
(if (bitwise_equal_p (@0, @3)
&& min_value_p (TREE_TYPE (@0), uniform_integer_cst_p (@2))
```
Etc.
We could have min_value_p use uniform_integer_cst_p inside it instead of doing
it before hand.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-11-02 20:53 [Bug tree-optimization/112356] New: `x == MIN & x > y` is not optimized to 0 if x was casted to signed from unsigned pinskia at gcc dot gnu.org
2023-11-02 20:53 ` [Bug tree-optimization/112356] " pinskia at gcc dot gnu.org
2023-11-02 21:00 ` pinskia at gcc dot gnu.org
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