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* [Bug tree-optimization/113677] New: Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization
@ 2024-01-31 1:46 pinskia at gcc dot gnu.org
2024-01-31 1:47 ` [Bug tree-optimization/113677] " pinskia at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-01-31 1:46 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113677
Bug ID: 113677
Summary: Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2,
...}>` optimization
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Take:
```
#define vect32 __attribute__((vector_size(4) ))
#define vect64 __attribute__((vector_size(8) ))
vect64 unsigned char f(vect32 unsigned char a)
{
vect32 unsigned char zero={0,0,0,0};
return __builtin_shufflevector (a, zero, 0, 1, 2, 3, 4, 5, 6, 7);
}
```
On x86_64 this produces:
```
f:
movd xmm0, edi
pxor xmm1, xmm1
punpckldq xmm0, xmm1
ret
```
We should just produce:
```
movd xmm0, edi
ret
```
In .optimized we get:
```
_1 = {a_2(D), { 0, 0, 0, 0 }};
_3 = VEC_PERM_EXPR <_1, { 0, 0, 0, 0, 0, 0, 0, 0 }, { 0, 1, 2, 3, 8, 9, 10,
11 }>;
return _3;
```
But _3 and _1 are the same ...
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/113677] Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization
2024-01-31 1:46 [Bug tree-optimization/113677] New: Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization pinskia at gcc dot gnu.org
@ 2024-01-31 1:47 ` pinskia at gcc dot gnu.org
2024-01-31 2:16 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-01-31 1:47 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113677
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target| |x86_64
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I should note I noticed this while working on adding V4QI support for aarch64
but it is definite a generic issue.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/113677] Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization
2024-01-31 1:46 [Bug tree-optimization/113677] New: Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization pinskia at gcc dot gnu.org
2024-01-31 1:47 ` [Bug tree-optimization/113677] " pinskia at gcc dot gnu.org
@ 2024-01-31 2:16 ` pinskia at gcc dot gnu.org
2024-01-31 8:27 ` rguenth at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-01-31 2:16 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113677
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target|x86_64 |x86_64 aarch64
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Here is another example, using 64/128 on aarch64:
```
#define vect64 __attribute__((vector_size(8) ))
#define vect128 __attribute__((vector_size(16) ))
vect128 unsigned int f(vect64 unsigned int a)
{
vect64 unsigned int zero={0, 0};
return __builtin_shufflevector (a, zero, 0, 1, 2, 3);
}
```
We get:
```
f:
movi v31.4s, 0
fmov d0, d0
zip1 v0.2d, v0.2d, v31.2d
```
This should just produce the `fmov` for little-endian and `mov/ins` for
big-endian.
Note for this part of the issue the aarch64 back-end represents zip using
UNSPEC where it could use VEC_CONCAT instead. And it would do the correct thing
there ...
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/113677] Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization
2024-01-31 1:46 [Bug tree-optimization/113677] New: Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization pinskia at gcc dot gnu.org
2024-01-31 1:47 ` [Bug tree-optimization/113677] " pinskia at gcc dot gnu.org
2024-01-31 2:16 ` pinskia at gcc dot gnu.org
@ 2024-01-31 8:27 ` rguenth at gcc dot gnu.org
2024-02-06 17:05 ` pinskia at gcc dot gnu.org
2024-03-08 5:08 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2024-01-31 8:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113677
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2024-01-31
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Yeah, most of the code in forwprop/match doesn't deal with the "new" permutes
where the result isn't the same length as the inputs.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/113677] Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization
2024-01-31 1:46 [Bug tree-optimization/113677] New: Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization pinskia at gcc dot gnu.org
` (2 preceding siblings ...)
2024-01-31 8:27 ` rguenth at gcc dot gnu.org
@ 2024-02-06 17:05 ` pinskia at gcc dot gnu.org
2024-03-08 5:08 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-02-06 17:05 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113677
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note it is not just about constants either.
Take:
```
#define vect64 __attribute__((vector_size(8) ))
#define vect128 __attribute__((vector_size(16) ))
vect128 unsigned int f(vect64 unsigned int a, vect64 unsigned int b)
{
vect64 unsigned int zero={0, 0};
return __builtin_shufflevector (a, b, 0, 1, 2, 3);
}
```
We get:
```
_1 = {a_3(D), { 0, 0 }};
_2 = {b_4(D), { 0, 0 }};
_5 = VEC_PERM_EXPR <_1, _2, { 0, 1, 4, 5 }>;
```
Which obvious could be done to just:
`_5 = {a_3(D), b_4(D)};`
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/113677] Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization
2024-01-31 1:46 [Bug tree-optimization/113677] New: Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization pinskia at gcc dot gnu.org
` (3 preceding siblings ...)
2024-02-06 17:05 ` pinskia at gcc dot gnu.org
@ 2024-03-08 5:08 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-03-08 5:08 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113677
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #4)
> Note it is not just about constants either.
That is the same as what is mentioned in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94301#c2 even :).
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-03-08 5:08 UTC | newest]
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2024-01-31 1:46 [Bug tree-optimization/113677] New: Missing `VEC_PERM_EXPR <{a, CST}, CST, {0, 1, 2, ...}>` optimization pinskia at gcc dot gnu.org
2024-01-31 1:47 ` [Bug tree-optimization/113677] " pinskia at gcc dot gnu.org
2024-01-31 2:16 ` pinskia at gcc dot gnu.org
2024-01-31 8:27 ` rguenth at gcc dot gnu.org
2024-02-06 17:05 ` pinskia at gcc dot gnu.org
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