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* [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types
@ 2023-02-19 13:37 lh_mouse at 126 dot com
2023-02-20 18:43 ` [Bug middle-end/108847] " pinskia at gcc dot gnu.org
` (11 more replies)
0 siblings, 12 replies; 13+ messages in thread
From: lh_mouse at 126 dot com @ 2023-02-19 13:37 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Bug ID: 108847
Summary: unnecessary bitwise AND on boolean types
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: lh_mouse at 126 dot com
Target Milestone: ---
Godbolt: https://gcc.godbolt.org/z/fsavMzMo7
```
void
set_bool(bool& fl, __UINT32_TYPE__ value)
{
fl |= value >> 31;
}
```
This code shifts a `uint32` to the right by 31 bits, so the result will only be
0 or 1.
Clang outputs:
```
set_bool(bool&, unsigned int): # @set_bool(bool&,
unsigned int)
shr esi, 31
or byte ptr [rdi], sil
ret
```
but GCC emits an additional unnecessary bitwise AND operation on the
destination operand:
```
set_bool(bool&, unsigned int):
shr esi, 31
or BYTE PTR [rdi], sil
and BYTE PTR [rdi], 1
ret
```
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] unnecessary bitwise AND on boolean types
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
@ 2023-02-20 18:43 ` pinskia at gcc dot gnu.org
2023-05-20 1:14 ` [Bug middle-end/108847] unnecessary bitwise AND on boolean types and shifting of the "sign" bit pinskia at gcc dot gnu.org
` (10 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-02-20 18:43 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Keywords|ABI |
Ever confirmed|0 |1
Severity|normal |enhancement
Last reconfirmed| |2023-02-20
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The workaround in this case is just to do:
((__INT32_TYPE__)value) < 0
instead of value>>31.
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
2023-02-20 18:43 ` [Bug middle-end/108847] " pinskia at gcc dot gnu.org
@ 2023-05-20 1:14 ` pinskia at gcc dot gnu.org
2023-05-20 23:31 ` pinskia at gcc dot gnu.org
` (9 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-05-20 1:14 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target|x86_64-*-* |x86_64-*-* aarch64-*-*
Status|NEW |ASSIGNED
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I am messing around in this area ....
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
2023-02-20 18:43 ` [Bug middle-end/108847] " pinskia at gcc dot gnu.org
2023-05-20 1:14 ` [Bug middle-end/108847] unnecessary bitwise AND on boolean types and shifting of the "sign" bit pinskia at gcc dot gnu.org
@ 2023-05-20 23:31 ` pinskia at gcc dot gnu.org
2023-05-20 23:34 ` [Bug middle-end/108847] [10/11/12/13/14 Regression] " pinskia at gcc dot gnu.org
` (8 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-05-20 23:31 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So looking into this a little futher.
The problem is VRP turns !=0 into (bool) and then expand comes along and
decides that a cast to bool needs &1 because well it just. I am going to look
into see if I can remove the &1 there ...
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [10/11/12/13/14 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (2 preceding siblings ...)
2023-05-20 23:31 ` pinskia at gcc dot gnu.org
@ 2023-05-20 23:34 ` pinskia at gcc dot gnu.org
2023-05-20 23:34 ` pinskia at gcc dot gnu.org
` (7 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-05-20 23:34 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|enhancement |trivial
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [10/11/12/13/14 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (3 preceding siblings ...)
2023-05-20 23:34 ` [Bug middle-end/108847] [10/11/12/13/14 Regression] " pinskia at gcc dot gnu.org
@ 2023-05-20 23:34 ` pinskia at gcc dot gnu.org
2023-05-20 23:36 ` pinskia at gcc dot gnu.org
` (6 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-05-20 23:34 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |14.0
Keywords| |deferred
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [10/11/12/13/14 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (4 preceding siblings ...)
2023-05-20 23:34 ` pinskia at gcc dot gnu.org
@ 2023-05-20 23:36 ` pinskia at gcc dot gnu.org
2023-05-27 6:50 ` pinskia at gcc dot gnu.org
` (5 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-05-20 23:36 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
VRP starting doing this in GCC 5:
Folding statement: _5 = _4 != 0;
Folded into: _5 = (bool) _4;
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [10/11/12/13/14 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (5 preceding siblings ...)
2023-05-20 23:36 ` pinskia at gcc dot gnu.org
@ 2023-05-27 6:50 ` pinskia at gcc dot gnu.org
2023-05-27 7:02 ` pinskia at gcc dot gnu.org
` (4 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-05-27 6:50 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Oh simple way to solve this to convert:
t2_7 = (unsigned int) t_4;
_1 = t1_6 | t2_7;
t_8 = _1 != 0;
Into:
t3_8 = t1_7 != 0;
_1 = t_5 | t3_8;
Which is smaller even.
(for bit_op (bit_ior bit_and bit_xor)
(simplify
(ne (bit_op (convert @0) @1) integer_zerop@2)
(if (TREE_CODE (TREE_TYPE (@0)) == BOOLEAN_TYPE
&& types_match (type, @0))
(bit_op @0 (ne @1 @2))))
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [10/11/12/13/14 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (6 preceding siblings ...)
2023-05-27 6:50 ` pinskia at gcc dot gnu.org
@ 2023-05-27 7:02 ` pinskia at gcc dot gnu.org
2023-09-17 1:49 ` [Bug middle-end/108847] [11/12/13/14 " pinskia at gcc dot gnu.org
` (3 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-05-27 7:02 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Just for reference here are the functions I tried to see which way was the best
(set_bool0 and set_bool0_ produce the best for x86):
void
set_bool(bool& fl, __UINT32_TYPE__ value)
{
bool t = fl;
__UINT32_TYPE__ t1 = value>>31;
__UINT32_TYPE__ t2 = t;
t = t2 | t1;
fl = t;
}
void
set_bool0(bool& fl, __UINT32_TYPE__ value)
{
bool t = fl;
__UINT32_TYPE__ t1 = value>>31;
bool t3 = t1;
t = t | t3;
fl = t;
}
void
set_bool0_(bool& fl, __INT32_TYPE__ value)
{
bool t = fl;
__UINT32_TYPE__ t1 = value<0;
bool t3 = t1;
t = t | t3;
fl = t;
}
void
set_bool1(bool& fl, __UINT32_TYPE__ value)
{
fl |= value >> 31;
}
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [11/12/13/14 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (7 preceding siblings ...)
2023-05-27 7:02 ` pinskia at gcc dot gnu.org
@ 2023-09-17 1:49 ` pinskia at gcc dot gnu.org
2024-03-08 15:38 ` law at gcc dot gnu.org
` (2 subsequent siblings)
11 siblings, 0 replies; 13+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-17 1:49 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
See Also| |https://gcc.gnu.org/bugzill
| |a/show_bug.cgi?id=52345
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Funny, the match pattern in comment #5 is similar to the one which I was
working on for PR 52345 .
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [11/12/13/14 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (8 preceding siblings ...)
2023-09-17 1:49 ` [Bug middle-end/108847] [11/12/13/14 " pinskia at gcc dot gnu.org
@ 2024-03-08 15:38 ` law at gcc dot gnu.org
2024-05-07 7:40 ` [Bug middle-end/108847] [11/12/13/14/15 " rguenth at gcc dot gnu.org
2024-08-01 9:31 ` [Bug middle-end/108847] [12/13/14/15 " jakub at gcc dot gnu.org
11 siblings, 0 replies; 13+ messages in thread
From: law at gcc dot gnu.org @ 2024-03-08 15:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Jeffrey A. Law <law at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |law at gcc dot gnu.org
Priority|P3 |P2
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [11/12/13/14/15 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (9 preceding siblings ...)
2024-03-08 15:38 ` law at gcc dot gnu.org
@ 2024-05-07 7:40 ` rguenth at gcc dot gnu.org
2024-08-01 9:31 ` [Bug middle-end/108847] [12/13/14/15 " jakub at gcc dot gnu.org
11 siblings, 0 replies; 13+ messages in thread
From: rguenth at gcc dot gnu.org @ 2024-05-07 7:40 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|14.0 |14.2
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 14.1 is being released, retargeting bugs to GCC 14.2.
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Bug middle-end/108847] [12/13/14/15 Regression] unnecessary bitwise AND on boolean types and shifting of the "sign" bit
2023-02-19 13:37 [Bug middle-end/108847] New: unnecessary bitwise AND on boolean types lh_mouse at 126 dot com
` (10 preceding siblings ...)
2024-05-07 7:40 ` [Bug middle-end/108847] [11/12/13/14/15 " rguenth at gcc dot gnu.org
@ 2024-08-01 9:31 ` jakub at gcc dot gnu.org
11 siblings, 0 replies; 13+ messages in thread
From: jakub at gcc dot gnu.org @ 2024-08-01 9:31 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108847
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|14.2 |14.3
--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 14.2 is being released, retargeting bugs to GCC 14.3.
^ permalink raw reply [flat|nested] 13+ messages in thread
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2023-02-20 18:43 ` [Bug middle-end/108847] " pinskia at gcc dot gnu.org
2023-05-20 1:14 ` [Bug middle-end/108847] unnecessary bitwise AND on boolean types and shifting of the "sign" bit pinskia at gcc dot gnu.org
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