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* [Bug target/114510] New: [14 Regression] missed proping of multiply by 2 into address of load/stores
@ 2024-03-28 6:58 pinskia at gcc dot gnu.org
2024-03-28 7:05 ` [Bug target/114510] " pinskia at gcc dot gnu.org
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-03-28 6:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114510
Bug ID: 114510
Summary: [14 Regression] missed proping of multiply by 2 into
address of load/stores
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Target: aarch64
Take:
```
int f(short *a, short *c, __SIZE_TYPE__ b)
{
return a[b] + c[b];
}
int f1(short *a, short *c, int b)
{
return a[b] + c[b];
}
```
These used to produce in GCC 13:
```
f:
ldrsh w3, [x0, x2, lsl 1]
ldrsh w0, [x1, x2, lsl 1]
add w0, w3, w0
ret
f1:
ldrsh w3, [x0, w2, sxtw 1]
ldrsh w0, [x1, w2, sxtw 1]
add w0, w3, w0
ret
```
But now f produces as of r14-9692-g839bc42772ba7a (but it looks like the change
happened much earlier):
```
f:
lsl x2, x2, 1
ldrsh w3, [x0, x2]
ldrsh w0, [x1, x2]
add w0, w3, w0
```
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/114510] [14 Regression] missed proping of multiply by 2 into address of load/stores
2024-03-28 6:58 [Bug target/114510] New: [14 Regression] missed proping of multiply by 2 into address of load/stores pinskia at gcc dot gnu.org
@ 2024-03-28 7:05 ` pinskia at gcc dot gnu.org
2024-03-28 7:05 ` pinskia at gcc dot gnu.org
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-03-28 7:05 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114510
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note it looks like fwprop was doing it in GCC 13 but not on the trunk due to a
cost reason. I have not looked further. There could be some cost issues in the
aarch64 backend dealing with address costs too.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/114510] [14 Regression] missed proping of multiply by 2 into address of load/stores
2024-03-28 6:58 [Bug target/114510] New: [14 Regression] missed proping of multiply by 2 into address of load/stores pinskia at gcc dot gnu.org
2024-03-28 7:05 ` [Bug target/114510] " pinskia at gcc dot gnu.org
@ 2024-03-28 7:05 ` pinskia at gcc dot gnu.org
2024-03-28 7:08 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-03-28 7:05 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114510
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note I was inspired to test this due to LLVM change:
https://github.com/llvm/llvm-project/pull/86894 .
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/114510] [14 Regression] missed proping of multiply by 2 into address of load/stores
2024-03-28 6:58 [Bug target/114510] New: [14 Regression] missed proping of multiply by 2 into address of load/stores pinskia at gcc dot gnu.org
2024-03-28 7:05 ` [Bug target/114510] " pinskia at gcc dot gnu.org
2024-03-28 7:05 ` pinskia at gcc dot gnu.org
@ 2024-03-28 7:08 ` pinskia at gcc dot gnu.org
2024-03-29 23:45 ` law at gcc dot gnu.org
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-03-28 7:08 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114510
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |14.0
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/114510] [14 Regression] missed proping of multiply by 2 into address of load/stores
2024-03-28 6:58 [Bug target/114510] New: [14 Regression] missed proping of multiply by 2 into address of load/stores pinskia at gcc dot gnu.org
` (2 preceding siblings ...)
2024-03-28 7:08 ` pinskia at gcc dot gnu.org
@ 2024-03-29 23:45 ` law at gcc dot gnu.org
2024-04-03 16:16 ` tnfchris at gcc dot gnu.org
2024-05-07 7:45 ` [Bug target/114510] [14/15 " rguenth at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: law at gcc dot gnu.org @ 2024-03-29 23:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114510
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] 7+ messages in thread
* [Bug target/114510] [14 Regression] missed proping of multiply by 2 into address of load/stores
2024-03-28 6:58 [Bug target/114510] New: [14 Regression] missed proping of multiply by 2 into address of load/stores pinskia at gcc dot gnu.org
` (3 preceding siblings ...)
2024-03-29 23:45 ` law at gcc dot gnu.org
@ 2024-04-03 16:16 ` tnfchris at gcc dot gnu.org
2024-05-07 7:45 ` [Bug target/114510] [14/15 " rguenth at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: tnfchris at gcc dot gnu.org @ 2024-04-03 16:16 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114510
Tamar Christina <tnfchris at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |tnfchris at gcc dot gnu.org
--- Comment #3 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
Richard's patch should fix this next year.
https://gcc.gnu.org/pipermail/gcc-patches/2023-October/634166.html
We'll then stop relying on combine or other passes to fix this.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/114510] [14/15 Regression] missed proping of multiply by 2 into address of load/stores
2024-03-28 6:58 [Bug target/114510] New: [14 Regression] missed proping of multiply by 2 into address of load/stores pinskia at gcc dot gnu.org
` (4 preceding siblings ...)
2024-04-03 16:16 ` tnfchris at gcc dot gnu.org
@ 2024-05-07 7:45 ` rguenth at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: rguenth at gcc dot gnu.org @ 2024-05-07 7:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114510
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 7:45 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2024-03-28 6:58 [Bug target/114510] New: [14 Regression] missed proping of multiply by 2 into address of load/stores pinskia at gcc dot gnu.org
2024-03-28 7:05 ` [Bug target/114510] " pinskia at gcc dot gnu.org
2024-03-28 7:05 ` pinskia at gcc dot gnu.org
2024-03-28 7:08 ` pinskia at gcc dot gnu.org
2024-03-29 23:45 ` law at gcc dot gnu.org
2024-04-03 16:16 ` tnfchris at gcc dot gnu.org
2024-05-07 7:45 ` [Bug target/114510] [14/15 " rguenth at gcc dot gnu.org
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