Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

cmd/internal/obj: implement auto-nosplit for arm64, ppc64 #13379

Open
rsc opened this issue Nov 24, 2015 · 4 comments
Open

cmd/internal/obj: implement auto-nosplit for arm64, ppc64 #13379

rsc opened this issue Nov 24, 2015 · 4 comments
Labels
compiler/runtime Issues related to the Go compiler and/or runtime.
Milestone
Unplanned

Comments

@rsc
Copy link
Contributor

rsc commented Nov 24, 2015

See #11482 and CL 17165. The fix was to add nosplit tags, but the implication is that arm64 and ppc64 do not have the same "auto-nosplit" optimization that the other architectures do for leaf functions with tiny frames. They should.
@rsc rsc added this to the Unplanned milestone Nov 24, 2015
@mwhudson
Copy link
Contributor

I think it's only cmd/internal/obj/x86 that implements this optimization, i.e. arm and mips need this too.

@gopherbot
Copy link
Contributor

CL https://golang.org/cl/31357 mentions this issue.

gopherbot pushed a commit that referenced this issue Oct 18, 2016
@mundaym
cmd/internal/obj/{ppc64,s390x}: mark functions with small stacks NOSPLIT
430b820 
This change omits the stack check on ppc64 and s390x when the size of
a stack frame is less than obj.StackSmall. This is an optimization
x86 already performs.

The effect on s390x isn't huge because we were already omitting the
stack check when the frame size was 0 (it shaves about 1K from the
size of bin/go). On ppc64 however this change reduces the size of the
.text section in bin/go by 33K (1%).

Updates #13379 (for ppc64).

Change-Id: I6af0eb987646bea47fcaf0a812db3496bab0f680
Reviewed-on: https://go-review.googlesource.com/31357
Reviewed-by: David Chase <drchase@google.com>
@mundaym mundaym mentioned this issue Dec 9, 2016
Closed
@mundaym mundaym mentioned this issue May 29, 2017
Closed
@randall77
Copy link
Contributor

Also 386. (amd64 has this optimization, but 386 doesn't.)

@randall77 randall77 reopened this Apr 8, 2019
@gopherbot
Copy link
Contributor

Change https://golang.org/cl/302853 mentions this issue: cmd/internal/obj/arm64: mark functions with small stacks NOSPLIT

gopherbot pushed a commit that referenced this issue Mar 22, 2021
cmd/internal/obj/arm64: mark functions with small stacks NOSPLIT
d8394bf 
This change omits the stack check on arm64 when the size of a stack
frame is less than obj.StackSmall.

The effect is not very significant, because CL 92040 has set the leaf
function with a framesize of 0 to NOFRAME, which makes the code
prologue on arm64 much closer to other architectures. But it is not
without effect, for example, it is effective for std library functions
such as runtime.usleep, fmt.isSpace, etc. Since this CL is very simple,
I think this optimization is worthwhile.

compilecmp results on linux/arm64:
name                      old time/op       new time/op       delta
Template                        284ms ± 1%        283ms ± 1%  -0.29%  (p=0.000 n=50+50)
Unicode                         125ms ± 2%        125ms ± 1%    ~     (p=0.445 n=49+49)
GoTypes                         1.70s ± 1%        1.69s ± 1%  -0.36%  (p=0.000 n=50+50)
Compiler                        124ms ± 1%        124ms ± 1%  -0.31%  (p=0.003 n=48+48)
SSA                             12.7s ± 1%        12.7s ± 1%    ~     (p=0.117 n=50+50)
Flate                           172ms ± 1%        171ms ± 1%  -0.55%  (p=0.000 n=50+50)
GoParser                        265ms ± 1%        264ms ± 1%  -0.23%  (p=0.000 n=47+48)
Reflect                         653ms ± 1%        646ms ± 1%  -1.12%  (p=0.000 n=48+50)
Tar                             246ms ± 1%        245ms ± 1%  -0.41%  (p=0.000 n=46+47)
XML                             328ms ± 1%        327ms ± 1%  -0.18%  (p=0.020 n=46+50)
LinkCompiler                    599ms ± 1%        598ms ± 1%    ~     (p=0.237 n=50+49)
ExternalLinkCompiler            1.87s ± 1%        1.87s ± 1%  -0.18%  (p=0.000 n=50+50)
LinkWithoutDebugCompiler        365ms ± 1%        364ms ± 2%    ~     (p=0.131 n=50+50)
[Geo mean]                      490ms             488ms       -0.32%

name                      old alloc/op      new alloc/op      delta
Template                       38.8MB ± 1%       38.8MB ± 1%  +0.16%  (p=0.013 n=47+49)
Unicode                        28.4MB ± 0%       28.4MB ± 0%    ~     (p=0.512 n=46+44)
GoTypes                         169MB ± 1%        169MB ± 1%    ~     (p=0.628 n=50+50)
Compiler                       23.2MB ± 1%       23.2MB ± 1%    ~     (p=0.424 n=46+44)
SSA                            1.55GB ± 0%       1.55GB ± 0%    ~     (p=0.603 n=48+50)
Flate                          23.7MB ± 1%       23.8MB ± 1%    ~     (p=0.797 n=50+50)
GoParser                       35.3MB ± 1%       35.3MB ± 1%    ~     (p=0.932 n=49+49)
Reflect                        85.0MB ± 0%       84.9MB ± 0%  -0.05%  (p=0.038 n=45+40)
Tar                            34.4MB ± 1%       34.5MB ± 1%    ~     (p=0.288 n=50+50)
XML                            43.8MB ± 2%       43.9MB ± 2%    ~     (p=0.798 n=46+49)
LinkCompiler                    136MB ± 0%        136MB ± 0%    ~     (p=0.750 n=50+50)
ExternalLinkCompiler            127MB ± 0%        127MB ± 0%    ~     (p=0.852 n=50+50)
LinkWithoutDebugCompiler       84.1MB ± 0%       84.1MB ± 0%    ~     (p=0.890 n=50+50)
[Geo mean]                     70.4MB            70.4MB       +0.01%

file      before    after     Δ       %
addr2line 4006004   4006012   +8      +0.000%
asm       4936863   4936919   +56     +0.001%
buildid   2594947   2594859   -88     -0.003%
cgo       4399702   4399806   +104    +0.002%
compile   22233139  22233107  -32     -0.000%
cover     4443681   4443785   +104    +0.002%
dist      3365902   3365806   -96     -0.003%
doc       3776175   3776231   +56     +0.001%
fix       3218624   3218552   -72     -0.002%
nm        3923345   3923329   -16     -0.000%
objdump   4295473   4295673   +200    +0.005%
pack      2390561   2390497   -64     -0.003%
pprof     12866419  12866275  -144    -0.001%
test2json 2587113   2587129   +16     +0.001%
trace     9609814   9609710   -104    -0.001%
vet       6790272   6791048   +776    +0.011%
total     106832751 106833455 +704    +0.001%

Updates #13379 (for arm64)

Change-Id: I07664ab0b978c66c0b18b8482222e9ba3772290d
Reviewed-on: https://go-review.googlesource.com/c/go/+/302853
Reviewed-by: eric fang <eric.fang@arm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: eric fang <eric.fang@arm.com>
Run-TryBot: eric fang <eric.fang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
@gopherbot gopherbot added the compiler/runtime Issues related to the Go compiler and/or runtime. label Jul 13, 2022
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
compiler/runtime Issues related to the Go compiler and/or runtime.
Projects
None yet
Milestone
Unplanned
Development

No branches or pull requests
4 participants
@rsc @mwhudson @randall77 @gopherbot