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* [Bug target/65225] New: [AArch64] Various aarch64_rtx_costs improvements
@ 2015-02-26 18:00 ktkachov at gcc dot gnu.org
2015-02-26 18:03 ` [Bug target/65225] " ktkachov at gcc dot gnu.org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: ktkachov at gcc dot gnu.org @ 2015-02-26 18:00 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65225
Bug ID: 65225
Summary: [AArch64] Various aarch64_rtx_costs improvements
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: ktkachov at gcc dot gnu.org
Target: aarch64*
The aarch64 rtx costs walker could be improved. Some particular areas:
- In the MINUS case, the cost of new_op1 is not included at all
- In the PLUS and MINUS case, extends and extended shifts are costed as
alu_arith rather than extend_arith
- In the PLUS and MINUS case if there is a ASHIFT or MULT after an
extend/extended shift, the cost calculated in rtx_mult_cost is as if it was a
plain PLUS/MINUS. If the multiply is by a power of 2, it calculates the cost as
a arith_shift rather than extend_arith. If it was ASHIFT the cost is wrong as
it expects a MULT rather than ASHIFT, so shift immediates which happen to be a
power of 2 get a different cost.
- In the ASHIFT case, if there is an extend the cost of extend should be used
rather than a shift.
ASHIFT 1 should use alu cost rather than shift cost (we emit an add if shift
cost is higher than alu cost)
- In the ASHIFRT/LSHIFTRT case the extend logic is missing.
- In the ABS case for integer, speed cost should be 2 ALU instructions rather
than 4.
- In the and-immediate case look into handling ZERO_EXTRACT.
- The NOT case misses logic for shifts (despite the comment, calculating shift
cost separately is not correct) - this can be costed as ORN with zero similar
to the way NEG works.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/65225] [AArch64] Various aarch64_rtx_costs improvements
2015-02-26 18:00 [Bug target/65225] New: [AArch64] Various aarch64_rtx_costs improvements ktkachov at gcc dot gnu.org
@ 2015-02-26 18:03 ` ktkachov at gcc dot gnu.org
2015-05-15 14:38 ` ramana at gcc dot gnu.org
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: ktkachov at gcc dot gnu.org @ 2015-02-26 18:03 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65225
ktkachov at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |6.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/65225] [AArch64] Various aarch64_rtx_costs improvements
2015-02-26 18:00 [Bug target/65225] New: [AArch64] Various aarch64_rtx_costs improvements ktkachov at gcc dot gnu.org
2015-02-26 18:03 ` [Bug target/65225] " ktkachov at gcc dot gnu.org
@ 2015-05-15 14:38 ` ramana at gcc dot gnu.org
2015-05-15 14:40 ` ktkachov at gcc dot gnu.org
2015-06-02 9:21 ` ktkachov at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: ramana at gcc dot gnu.org @ 2015-05-15 14:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65225
Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Last reconfirmed| |2015-05-15
CC| |ramana at gcc dot gnu.org
Assignee|unassigned at gcc dot gnu.org |ktkachov at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #1 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
Presumably yours ?
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/65225] [AArch64] Various aarch64_rtx_costs improvements
2015-02-26 18:00 [Bug target/65225] New: [AArch64] Various aarch64_rtx_costs improvements ktkachov at gcc dot gnu.org
2015-02-26 18:03 ` [Bug target/65225] " ktkachov at gcc dot gnu.org
2015-05-15 14:38 ` ramana at gcc dot gnu.org
@ 2015-05-15 14:40 ` ktkachov at gcc dot gnu.org
2015-06-02 9:21 ` ktkachov at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: ktkachov at gcc dot gnu.org @ 2015-05-15 14:40 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65225
--- Comment #2 from ktkachov at gcc dot gnu.org ---
(In reply to Ramana Radhakrishnan from comment #1)
> Presumably yours ?
Yes, and I think it's fixed. At least all the important aarch64 patches are in
with.
https://gcc.gnu.org/ml/gcc-patches/2015-05/msg00013.html is still waiting
though
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/65225] [AArch64] Various aarch64_rtx_costs improvements
2015-02-26 18:00 [Bug target/65225] New: [AArch64] Various aarch64_rtx_costs improvements ktkachov at gcc dot gnu.org
` (2 preceding siblings ...)
2015-05-15 14:40 ` ktkachov at gcc dot gnu.org
@ 2015-06-02 9:21 ` ktkachov at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: ktkachov at gcc dot gnu.org @ 2015-06-02 9:21 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65225
ktkachov at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution|--- |FIXED
--- Comment #3 from ktkachov at gcc dot gnu.org ---
The aarch64 costs issue that I could find have been fixed on trunk for GCC 6
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-06-02 9:21 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2015-02-26 18:00 [Bug target/65225] New: [AArch64] Various aarch64_rtx_costs improvements ktkachov at gcc dot gnu.org
2015-02-26 18:03 ` [Bug target/65225] " ktkachov at gcc dot gnu.org
2015-05-15 14:38 ` ramana at gcc dot gnu.org
2015-05-15 14:40 ` ktkachov at gcc dot gnu.org
2015-06-02 9:21 ` ktkachov at gcc dot gnu.org
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