public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug tree-optimization/111542] New: [11/12/13/14 Regression]
@ 2023-09-22 18:51 pinskia at gcc dot gnu.org
2023-09-22 18:54 ` [Bug tree-optimization/111542] " pinskia at gcc dot gnu.org
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-22 18:51 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111542
Bug ID: 111542
Summary: [11/12/13/14 Regression]
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Take:
```
_Bool f(int x,int y)
{
_Bool a = x == 0;
_Bool b = y == 0;
_Bool t = a & b;
return t & !a;
}
```
This used to optimize to 0 in GCC 6 but starting with GCC 7, we get:
```
_5 = x_2(D) | y_3(D);
_6 = _5 == 0;
_1 = x_2(D) != 0;
_7 = _1 & _6;
```
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/111542] [11/12/13/14 Regression]
2023-09-22 18:51 [Bug tree-optimization/111542] New: [11/12/13/14 Regression] pinskia at gcc dot gnu.org
@ 2023-09-22 18:54 ` pinskia at gcc dot gnu.org
2023-09-22 18:55 ` [Bug tree-optimization/111542] [11/12/13/14 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations pinskia at gcc dot gnu.org
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-22 18:54 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111542
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot gnu.org
Ever confirmed|0 |1
Last reconfirmed| |2023-09-22
Status|UNCONFIRMED |ASSIGNED
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Mine.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/111542] [11/12/13/14 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations
2023-09-22 18:51 [Bug tree-optimization/111542] New: [11/12/13/14 Regression] pinskia at gcc dot gnu.org
2023-09-22 18:54 ` [Bug tree-optimization/111542] " pinskia at gcc dot gnu.org
@ 2023-09-22 18:55 ` pinskia at gcc dot gnu.org
2023-09-23 20:14 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-22 18:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111542
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |14.0
Summary|[11/12/13/14 Regression] |[11/12/13/14 Regression]
| |(a==0)&(b==0) into `(a|b)
| |== 0` optimization
| |sometimes gets in the way
| |of other optimizations
Known to fail| |7.1.0
Known to work| |6.1.0
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/111542] [11/12/13/14 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations
2023-09-22 18:51 [Bug tree-optimization/111542] New: [11/12/13/14 Regression] pinskia at gcc dot gnu.org
2023-09-22 18:54 ` [Bug tree-optimization/111542] " pinskia at gcc dot gnu.org
2023-09-22 18:55 ` [Bug tree-optimization/111542] [11/12/13/14 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations pinskia at gcc dot gnu.org
@ 2023-09-23 20:14 ` pinskia at gcc dot gnu.org
2023-09-23 20:23 ` pinskia at gcc dot gnu.org
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-23 20:14 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111542
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note IOR with != 0 has the same issue.
Full testcase:
```
_Bool f_and(int x,int y)
{
_Bool a = x == 0;
_Bool b = y == 0;
_Bool t = a & b;
return t & !a;
}
_Bool f_or(int x,int y)
{
_Bool a = x != 0;
_Bool b = y != 0;
_Bool t = a | b;
return t | !a;
}
```
Match pattern:
```
(for bitop (bit_ior bit_and)
cmp1 (eq ne )
cmp2 (ne eq )
(simplify
(bitop:c
(cmp1 @1 integer_zerop)
(cmp2 (bit_ior:c @0 @1) integer_zerop))
{ constant_boolean_node (bitop == BIT_IOR_EXPR, type); }))
```
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/111542] [11/12/13/14 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations
2023-09-22 18:51 [Bug tree-optimization/111542] New: [11/12/13/14 Regression] pinskia at gcc dot gnu.org
` (2 preceding siblings ...)
2023-09-23 20:14 ` pinskia at gcc dot gnu.org
@ 2023-09-23 20:23 ` pinskia at gcc dot gnu.org
2023-10-17 13:00 ` rguenth at gcc dot gnu.org
2024-05-07 7:42 ` [Bug tree-optimization/111542] [11/12/13/14/15 " rguenth at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-09-23 20:23 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111542
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> Match pattern:
> ```
> (for bitop (bit_ior bit_and)
> cmp1 (eq ne )
> cmp2 (ne eq )
> (simplify
> (bitop:c
> (cmp1 @1 integer_zerop)
> (cmp2 (bit_ior:c @0 @1) integer_zerop))
> { constant_boolean_node (bitop == BIT_IOR_EXPR, type); }))
> ```
But this breaks generic-match building of the function:
tree
generic_simplify_92 (location_t ARG_UNUSED (loc), const tree ARG_UNUSED (type),
tree ARG_UNUSED (_p0), tree ARG_UNUSED (_p1), tree *captures,
const enum tree_code ARG_UNUSED (bitop),
const enum tree_code ARG_UNUSED (cmp1),
const enum tree_code ARG_UNUSED (cmp2))
{
const bool debug_dump = dump_file && (dump_flags & TDF_FOLDING);
if (TREE_SIDE_EFFECTS (_p0)) goto next_after_fail192;
if (TREE_SIDE_EFFECTS (_p1)) goto next_after_fail192;
if (UNLIKELY (!dbg_cnt (match))) goto next_after_fail192;
{
tree _r;
_r = constant_boolean_node (bitop == BIT_IOR_EXPR, type);
if (UNLIKELY (debug_dump)) generic_dump_logs ("match.pd", 136, __FILE__,
__LINE__, true);
return _r;
}
next_after_fail192:;
return NULL_TREE;
}
captures is not used .
I guess I could check TREE_SIDE_EFFECTS on @0/@1 to workaround that issue.
Like so:
```
(for bitop (bit_ior bit_and)
cmp1 (eq ne )
cmp2 (ne eq )
(simplify
(bitop:c
(cmp1 @1 integer_zerop)
(cmp2 (bit_ior:c @0 @1) integer_zerop))
(if (GIMPLE || (!TREE_SIDE_EFFECTS (@0)
&& !TREE_SIDE_EFFECTS (@1)))
{ constant_boolean_node (bitop == BIT_IOR_EXPR, type); })))
```
I had assumed genmatch would generate that code that would use @0/@1 if they
had side effects. Maybe because I match @0 twice, it assumed we would be using
the captures (I have not looked though).
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/111542] [11/12/13/14 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations
2023-09-22 18:51 [Bug tree-optimization/111542] New: [11/12/13/14 Regression] pinskia at gcc dot gnu.org
` (3 preceding siblings ...)
2023-09-23 20:23 ` pinskia at gcc dot gnu.org
@ 2023-10-17 13:00 ` rguenth at gcc dot gnu.org
2024-05-07 7:42 ` [Bug tree-optimization/111542] [11/12/13/14/15 " rguenth at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-10-17 13:00 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111542
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Priority|P3 |P2
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/111542] [11/12/13/14/15 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations
2023-09-22 18:51 [Bug tree-optimization/111542] New: [11/12/13/14 Regression] pinskia at gcc dot gnu.org
` (4 preceding siblings ...)
2023-10-17 13:00 ` rguenth at gcc dot gnu.org
@ 2024-05-07 7:42 ` rguenth at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: rguenth at gcc dot gnu.org @ 2024-05-07 7:42 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111542
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|14.0 |14.2
--- Comment #4 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] 7+ messages in thread
end of thread, other threads:[~2024-05-07 7:42 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-09-22 18:51 [Bug tree-optimization/111542] New: [11/12/13/14 Regression] pinskia at gcc dot gnu.org
2023-09-22 18:54 ` [Bug tree-optimization/111542] " pinskia at gcc dot gnu.org
2023-09-22 18:55 ` [Bug tree-optimization/111542] [11/12/13/14 Regression] (a==0)&(b==0) into `(a|b) == 0` optimization sometimes gets in the way of other optimizations pinskia at gcc dot gnu.org
2023-09-23 20:14 ` pinskia at gcc dot gnu.org
2023-09-23 20:23 ` pinskia at gcc dot gnu.org
2023-10-17 13:00 ` rguenth at gcc dot gnu.org
2024-05-07 7:42 ` [Bug tree-optimization/111542] [11/12/13/14/15 " rguenth at gcc dot gnu.org
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).