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* [Bug tree-optimization/101540] New: CONSTRUCTOR for vector(1) should just be VCE
@ 2021-07-20 22:01 pinskia at gcc dot gnu.org
2021-07-21 7:00 ` [Bug tree-optimization/101540] " rguenth at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-07-20 22:01 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101540
Bug ID: 101540
Summary: CONSTRUCTOR for vector(1) should just be VCE
Product: gcc
Version: 12.0
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: ---
I noticed with the following source:
typedef unsigned char __attribute__((__vector_size__ (1))) W;
typedef unsigned char __attribute__((__vector_size__ (8))) V;
typedef unsigned short __attribute__((__vector_size__ (16))) U;
unsigned short us;
W
foo (unsigned char uc)
{
V v = __builtin_convertvector ((U){ } >= us, V);
return __builtin_shufflevector ((W){ }, v, 4) & uc;
}
int
main (void)
{
W x = foo (5);
if (x[0] != 5)
__builtin_abort();
return 0;
}
----- CUT ----
We produce
_6 = {uc_10(D)};
But this should be the same as
_6 = VIEW_CONVERT_EXPR<uc_10>
--- CUT ---
This is what we get in the IR:
_6 = {uc_10(D)};
_14 = BIT_FIELD_REF <_4, 8, 0>;
_15 = VIEW_CONVERT_EXPR<unsigned char>(_6);
_16 = _14 & _15;
_17 = VIEW_CONVERT_EXPR<W>(_16);
We do change the BIT_FIELD_REF that was assigned to _15 to a VCE though.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/101540] CONSTRUCTOR for vector(1) should just be VCE
2021-07-20 22:01 [Bug tree-optimization/101540] New: CONSTRUCTOR for vector(1) should just be VCE pinskia at gcc dot gnu.org
@ 2021-07-21 7:00 ` rguenth at gcc dot gnu.org
2021-11-28 8:55 ` pinskia at gcc dot gnu.org
2021-11-28 17:57 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2021-07-21 7:00 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101540
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Last reconfirmed| |2021-07-21
Status|UNCONFIRMED |NEW
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed. forwprop has simplify_vector_constructor for example.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/101540] CONSTRUCTOR for vector(1) should just be VCE
2021-07-20 22:01 [Bug tree-optimization/101540] New: CONSTRUCTOR for vector(1) should just be VCE pinskia at gcc dot gnu.org
2021-07-21 7:00 ` [Bug tree-optimization/101540] " rguenth at gcc dot gnu.org
@ 2021-11-28 8:55 ` pinskia at gcc dot gnu.org
2021-11-28 17:57 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-11-28 8:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101540
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot gnu.org
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I think I have a patch.
Basically adding this to simplify_vector_constructor should work for most
cases.
if (nelts == 1 && CONSTRUCTOR_NELTS (op) == 1)
{
tree op1 = CONSTRUCTOR_ELT (op, 0);
if (useless_type_conversion_p (elem_type, TREE_TYPE (op1)))
{
op1 = build1 (VIEW_CONVERT_EXPR, type, op1);
gimple_assign_set_rhs_from_tree (gsi, op1);
update_stmt (gsi_stmt (*gsi));
return true;
}
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/101540] CONSTRUCTOR for vector(1) should just be VCE
2021-07-20 22:01 [Bug tree-optimization/101540] New: CONSTRUCTOR for vector(1) should just be VCE pinskia at gcc dot gnu.org
2021-07-21 7:00 ` [Bug tree-optimization/101540] " rguenth at gcc dot gnu.org
2021-11-28 8:55 ` pinskia at gcc dot gnu.org
@ 2021-11-28 17:57 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-11-28 17:57 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101540
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
URL| |https://gcc.gnu.org/piperma
| |il/gcc-patches/2021-Novembe
| |r/585597.html
Keywords| |patch
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Patch submitted:
https://gcc.gnu.org/pipermail/gcc-patches/2021-November/585597.html
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-11-28 17:57 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-07-20 22:01 [Bug tree-optimization/101540] New: CONSTRUCTOR for vector(1) should just be VCE pinskia at gcc dot gnu.org
2021-07-21 7:00 ` [Bug tree-optimization/101540] " rguenth at gcc dot gnu.org
2021-11-28 8:55 ` pinskia at gcc dot gnu.org
2021-11-28 17:57 ` pinskia at gcc dot gnu.org
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