Commit graph

162 commits

Author SHA1 Message Date
David Chase
b64f549ba9 cmd/compile: ignore OXXX nodes in closure captured vars list
Added a debug flag "-d closure" to explain compilation of
closures (should this be done some other way? Should we
rewrite the "-m" flag to "-d escapes"?)  Used this to
discover that cause was an OXXX node in the captured vars
list, and in turn noticed that OXXX nodes are explicitly
ignored in all other processing of captured variables.

Couldn't figure out a reproducer, did verify that this OXXX
was not caused by an unnamed return value (which is one use
of these).  Verified lack of heap allocation by examining -S
output.

Assembly:
(runtime/mgc.go:1371) PCDATA $0, $2
(runtime/mgc.go:1371) CALL "".notewakeup(SB)
(runtime/mgc.go:1377) LEAQ "".gcBgMarkWorker.func1·f(SB), AX
(runtime/mgc.go:1404) MOVQ AX, (SP)
(runtime/mgc.go:1404) MOVQ "".autotmp_2242+88(SP), CX
(runtime/mgc.go:1404) MOVQ CX, 8(SP)
(runtime/mgc.go:1404) LEAQ go.string."GC worker (idle)"(SB), AX
(runtime/mgc.go:1404) MOVQ AX, 16(SP)
(runtime/mgc.go:1404) MOVQ $16, 24(SP)
(runtime/mgc.go:1404) MOVB $20, 32(SP)
(runtime/mgc.go:1404) MOVQ $0, 40(SP)
(runtime/mgc.go:1404) PCDATA $0, $2
(runtime/mgc.go:1404) CALL "".gopark(SB)

Added a check for compiling_runtime to ensure that this is
caught in the future.  Added a test to test the check.
Verified that 1.5.3 did NOT reject the test case when
compiled with -+ flag, so this is not a recently added bug.

Cause of bug is two-part -- there was no leaking closure
detection ever, and instead it relied on capture-of-variables
to trigger compiling_runtime test, but closures improved in
1.5.3 so that mere capture of a value did not also capture
the variable, which thus allowed closures to escape, as well
as this case where the escape was spurious.  In
fixedbugs/issue14999.go, compare messages for f and g;
1.5.3 would reject g, but not f.  1.4 rejects both because
1.4 heap-allocates parameter x for both.

Fixes #14999.

Change-Id: I40bcdd27056810628e96763a44f2acddd503aee1
Reviewed-on: https://go-review.googlesource.com/21322
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-01 02:08:56 +00:00
Michel Lespinasse
859b63cc09 cmd/compile: optimize remaining convT2I calls
See #14874
Updates #6853

This change adds a compiler optimization for non pointer shaped convT2I.
Since itab symbols are now emitted by the compiler, the itab address can
be passed directly to convT2I instead of passing the iface type and a
cache pointer argument.

Compilebench results for the 5-commits series ending here:

name       old time/op     new time/op     delta
Template       336ms ± 4%      344ms ± 4%   +2.61%          (p=0.027 n=9+8)
Unicode        165ms ± 6%      173ms ± 7%   +5.11%          (p=0.014 n=9+9)
GoTypes        1.09s ± 1%      1.06s ± 2%   -3.29%          (p=0.000 n=9+9)
Compiler       5.09s ±10%      4.75s ±10%   -6.64%        (p=0.011 n=10+10)
MakeBash       31.1s ± 5%      30.3s ± 3%     ~           (p=0.089 n=10+10)

name       old text-bytes  new text-bytes  delta
HelloSize       558k ± 0%       558k ± 0%   +0.02%        (p=0.000 n=10+10)
CmdGoSize      6.24M ± 0%      6.11M ± 0%   -2.11%        (p=0.000 n=10+10)

name       old data-bytes  new data-bytes  delta
HelloSize      3.66k ± 0%      3.74k ± 0%   +2.41%        (p=0.000 n=10+10)
CmdGoSize       134k ± 0%       162k ± 0%  +20.76%        (p=0.000 n=10+10)

name       old bss-bytes   new bss-bytes   delta
HelloSize       126k ± 0%       126k ± 0%     ~     (all samples are equal)
CmdGoSize       149k ± 0%       146k ± 0%   -2.17%        (p=0.000 n=10+10)

name       old exe-bytes   new exe-bytes   delta
HelloSize       924k ± 0%       924k ± 0%   +0.05%        (p=0.000 n=10+10)
CmdGoSize      9.77M ± 0%      9.62M ± 0%   -1.47%        (p=0.000 n=10+10)

Change-Id: Ib230ddc04988824035c32287ae544a965fedd344
Reviewed-on: https://go-review.googlesource.com/20902
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Michel Lespinasse <walken@google.com>
2016-03-29 02:21:50 +00:00
Michel Lespinasse
f00bbd5f81 cmd/compile: emit itabs and itablinks
See #14874

This change tells the compiler to emit itab and itablink symbols in
situations where they could be useful; however the compiled code does
not actually make use of the new symbols yet.

Change-Id: I0db3e6ec0cb1f3b7cebd4c60229e4a48372fe586
Reviewed-on: https://go-review.googlesource.com/20888
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Michel Lespinasse <walken@google.com>
2016-03-29 02:18:03 +00:00
Marvin Stenger
bd83cc6dae cmd/compile: prettify loop iterations
This commit replaces some of

for i := len(x) - 1; i >= 0; i-- {...}

style loops, which do not rely on reverse iteration order.

Change-Id: I5542834286562da058200c06e7a173b13760e54d
Reviewed-on: https://go-review.googlesource.com/21044
Reviewed-by: Keith Randall <khr@golang.org>
2016-03-23 22:49:49 +00:00
Josh Bleecher Snyder
34699bc7a8 cmd/compile: reduce use of **Node parameters
Escape analysis has a hard time with tree-like
structures (see #13493 and #14858).
This is unlikely to change.
As a result, when invoking a function that accepts
a **Node parameter, we usually allocate a *Node
on the heap. This happens a whole lot.

This CL changes functions from taking a **Node
to acting more like append: It both modifies
the input and returns a replacement for it.

Because of the cascading nature of escape analysis,
in order to get the benefits, I had to modify
almost all such functions. The remaining functions
are in racewalk and the backend. I would be happy
to update them as well in a separate CL.

This CL was created by manually updating the
function signatures and the directly impacted
bits of code. The callsites were then automatically
updated using a bespoke script:
https://gist.github.com/josharian/046b1be7aceae244de39

For ease of reviewing and future understanding,
this CL is also broken down into four CLs,
mailed separately, which show the manual
and the automated changes separately.
They are CLs 20990, 20991, 20992, and 20993.

Passes toolstash -cmp.

name       old time/op     new time/op     delta
Template       335ms ± 5%      324ms ± 5%   -3.35%        (p=0.000 n=23+24)
Unicode        176ms ± 9%      165ms ± 6%   -6.12%        (p=0.000 n=23+24)
GoTypes        1.10s ± 4%      1.07s ± 2%   -2.77%        (p=0.000 n=24+24)
Compiler       5.31s ± 3%      5.15s ± 3%   -2.95%        (p=0.000 n=24+24)
MakeBash       41.6s ± 1%      41.7s ± 2%     ~           (p=0.586 n=23+23)

name       old alloc/op    new alloc/op    delta
Template      63.3MB ± 0%     62.4MB ± 0%   -1.36%        (p=0.000 n=25+23)
Unicode       42.4MB ± 0%     41.6MB ± 0%   -1.99%        (p=0.000 n=24+25)
GoTypes        220MB ± 0%      217MB ± 0%   -1.11%        (p=0.000 n=25+25)
Compiler       994MB ± 0%      973MB ± 0%   -2.08%        (p=0.000 n=24+25)

name       old allocs/op   new allocs/op   delta
Template        681k ± 0%       574k ± 0%  -15.71%        (p=0.000 n=24+25)
Unicode         518k ± 0%       413k ± 0%  -20.34%        (p=0.000 n=25+24)
GoTypes        2.08M ± 0%      1.78M ± 0%  -14.62%        (p=0.000 n=25+25)
Compiler       9.26M ± 0%      7.64M ± 0%  -17.48%        (p=0.000 n=25+25)

name       old text-bytes  new text-bytes  delta
HelloSize       578k ± 0%       578k ± 0%     ~     (all samples are equal)
CmdGoSize      6.46M ± 0%      6.46M ± 0%     ~     (all samples are equal)

name       old data-bytes  new data-bytes  delta
HelloSize       128k ± 0%       128k ± 0%     ~     (all samples are equal)
CmdGoSize       281k ± 0%       281k ± 0%     ~     (all samples are equal)

name       old exe-bytes   new exe-bytes   delta
HelloSize       921k ± 0%       921k ± 0%     ~     (all samples are equal)
CmdGoSize      9.86M ± 0%      9.86M ± 0%     ~     (all samples are equal)

Change-Id: I277d95bd56d51c166ef7f560647aeaa092f3f475
Reviewed-on: https://go-review.googlesource.com/20959
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-22 14:11:36 +00:00
Dave Cheney
39af1eb96f cmd/internal/obj: remove Link.Windows field
This CL addresses a long standing CL by rsc by pushing the use of
Link.Windows down to its two users.

Link.Window was always initalised with the value of runtime.GOOS so
this does not affect cross compilation.

Change-Id: Ibbae068f8b5aad06336909691f094384caf12352
Reviewed-on: https://go-review.googlesource.com/20869
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-21 04:07:09 +00:00
Josh Bleecher Snyder
ec7c494535 cmd/compile: remove typechecklist
Convert remaining uses to typecheckslice.

Passes toolstash -cmp.

Change-Id: I6ed0877386fb6c0b036e8ee5a228433343855abd
Reviewed-on: https://go-review.googlesource.com/20905
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-20 00:34:42 +00:00
Ian Lance Taylor
65b4020403 cmd/compile: don't create 2 Sym's and 2 Node's for every string
For every string constant the compiler was creating 2 Sym's and 2
Node's.  It would never refer to them again, but would keep them alive
in gostringpkg.  This changes the code to just use obj.LSym's instead.

When compiling x/tools/go/types, this yields about a 15% reduction in
the number of calls to newname and a 3% reduction in the total number of
Node objects.  Unfortunately I couldn't see any change in compile time,
but reducing memory usage is desirable anyhow.

Passes toolstash -cmp.

Change-Id: I24f1cb1e6cff0a3afba4ca66f7166874917a036b
Reviewed-on: https://go-review.googlesource.com/20792
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-17 16:15:11 +00:00
Dave Cheney
cea5d26aa2 cmd/compile/internal/gc: remove Thearch.Linkarchinit
Change-Id: I8e990204c7a1e65d6b8e4262f6b5b9bd0cb3540c
Reviewed-on: https://go-review.googlesource.com/20725
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-03-15 15:29:39 +00:00
Matthew Dempsky
9d7b2b7b10 cmd/compile: move universe block code into new universe.go
Move lexinit, typeinit, lexinit1, and lexfini into new universe.go
file, and give them a more idiomatic and descriptive API. No code
changes.

Change-Id: I0e9b25dcc86ad10f4b990dc02bd33477b488cc85
Reviewed-on: https://go-review.googlesource.com/20604
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-03-11 23:56:56 +00:00
Robert Griesemer
76461c93a1 cmd/compile: move lexn and lexname into lex.go (cleanup)
Missed these two declarations in the previous cleanup.

Change-Id: I54ff3accd387dd90e12847daccf4477169797f81
Reviewed-on: https://go-review.googlesource.com/20603
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-11 23:26:59 +00:00
Robert Griesemer
998b6dd75c cmd/compile: move lexer into separate file (cleanup)
This is really moving all the non-lexer pieces out of lex.go
into main.go. It's always been confusing that the top-most
compiler entry point (Main) is in the same file with the
lexer. Both files remain of substantial size (> 1000 lines),
which justifies this even more.

No other changes.

Change-Id: I03895589d5e3cc2340580350bbc1420539893dfc
Reviewed-on: https://go-review.googlesource.com/20601
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-11 22:59:57 +00:00