uint8(s.b & 0xff) ought to produce same code as uint8(s.b)
but it did not. RLH found this one looking for moles to
whack in the GC code.
Change-Id: I883d68ec7a5746d652712be84a274a11256b3b33
Reviewed-on: https://go-review.googlesource.com/20141
Reviewed-by: Keith Randall <khr@golang.org>
Count only the runes up to the requested precision
to decide where to truncate a string.
Change the loop within truncate to need fewer jumps.
name old time/op new time/op delta
SprintfTruncateString-2 188ns ± 3% 155ns ± 3% -17.43% (p=0.000 n=20+20)
Change-Id: I17ca9fc0bb8bf7648599df48e4785251bbc31e99
Reviewed-on: https://go-review.googlesource.com/20098
Reviewed-by: Rob Pike <r@golang.org>
- removed lots of unnecessary int(x) casts
- removed parserline() - was inconsistently used anyway
- minor simplifications in dcl.go
Change-Id: Ibf7de679eea528a31c9692ef1c76a1d9b3239211
Reviewed-on: https://go-review.googlesource.com/20131
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This promotes a connection hang during TLS handshake to a proper error.
This doesn't fully address #14539 because the error reported in that
case is a write-on-socket-not-connected error, which implies that an
earlier error during connection setup is not being checked, but it is
an improvement over the current behaviour.
Updates #14539.
Change-Id: I0571a752d32d5303db48149ab448226868b19495
Reviewed-on: https://go-review.googlesource.com/19990
Reviewed-by: Adam Langley <agl@golang.org>
It looks like the compiler still uses the Cfunc flag for functions
marked as //go:systemstack, but if I'm reading this right, that
doesn't apply here and the linker no longer needs Cfunc.
Change-Id: I63b9192c2f52f41401263c29dc8dfd8be8a901a1
Reviewed-on: https://go-review.googlesource.com/20105
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Unlike RFC 1951 (DEFLATE), bzip2 does not use zero-length Huffman codes
to indicate that the symbol is missing. Instead, bzip2 uses a sparse
bitmap to indicate which symbols are present. Thus, it is undefined what
happens when a length of zero is used. Thus, fix the parsing logic so that
the length cannot ever go below 1-bit similar to how the C logic does things.
To confirm that the C bzip2 utility chokes on this data:
$ echo "425a6836314159265359b1f7404b000000400040002000217d184682ee48
a70a12163ee80960" | xxd -r -p | bzip2 -d
bzip2: Data integrity error when decompressing
For reference see:
bzip2-1.0.6/decompress.c:320
Change-Id: Ic1568f8e7f80cdea51d887b4d712cc239c2fe85e
Reviewed-on: https://go-review.googlesource.com/20119
Run-TryBot: Joe Tsai <joetsai@digital-static.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This per-symbol table was written with the strategy:
1. record offset and write fake header
2. write body
3. seek back to fake header
4. write real header
This CL collects the per-symbol body into a []byte, then writes the
real header followed by the body to the output file. This saves two
seeks per-symbol and overwriting the fake header.
Small performance improvement (3.5%) in best-of-ten links of godoc:
tip: real 0m1.132s user 0m1.256s
this: real 0m1.090s user 0m1.210s
I'm not sure if the performance measured here alone justifies it,
but I think this is an easier to read style of code.
Change-Id: I1663901eb7c2ee330591b8b6550cdff0402ed5dc
Reviewed-on: https://go-review.googlesource.com/20074
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Used by DWARF writer changes in a followup CL.
Change-Id: I6ec40dcfeaba909d9b8f6cf2603bc5b85c1fa873
Reviewed-on: https://go-review.googlesource.com/20073
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Do some easy TODOs.
Move a bunch of other TODOs into bugs.
Change-Id: Iaba9dad6221a2af11b3cbcc512875f4a85842873
Reviewed-on: https://go-review.googlesource.com/20114
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
This commit modifies the style of a error message in case of -shadow.
Previously such a message would look like:
foo.go:42: declaration of err shadows declaration at shadow.go:13:
Changes of the commit include highlighting the variable name and
removing the ": "(space intended) at the end of the line:
foo.go:42: declaration of "err" shadows declaration at shadow.go:13
Fixes#14585.
Change-Id: Ia6a6bf396668dcba9a24f025a08d8826db31f434
Reviewed-on: https://go-review.googlesource.com/20093
Reviewed-by: Rob Pike <r@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The size calculation has been wrong since this code was first committed
in https://golang.org/cl/3120. The effect was that the compiler always
allocated a temporary buffer on the stack for a non-escaping string
concatenation. This turns out to make no practical difference, as the
compiler always allocates a buffer of the same size (32 bytes) and the
runtime only uses the temporary buffer if the concatenated strings
fit (check is in rawstringtmp in runtime/string.go).
The effect of this change is to avoid generating a temporary buffer on
the stack that will not be used.
Change-Id: Id632bfe3d6c113c9934c018a2dd4bcbf1784a63d
Reviewed-on: https://go-review.googlesource.com/20112
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This check seems to apply to all code instrumentation, not just -race.
Fixes#14589.
Change-Id: I16ae07749ede7c1e6ed06f472711638d195034ac
Reviewed-on: https://go-review.googlesource.com/20113
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Marvin Stenger <marvin.stenger94@gmail.com>
This is a subset of https://golang.org/cl/20022 with only the copyright
header lines, so the next CL will be smaller and more reviewable.
Go policy has been single space after periods in comments for some time.
The copyright header template at:
https://golang.org/doc/contribute.html#copyright
also uses a single space.
Make them all consistent.
Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0
Reviewed-on: https://go-review.googlesource.com/20111
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Also: Use same ordering of tokens in the various tables/maps.
Change-Id: Ief84c6ca3da36213ace6b2c10b513e2ca16318ab
Reviewed-on: https://go-review.googlesource.com/20110
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
SSA is a real compiler now, don't trigger on function names.
Change-Id: Iaf6dd78248c1b6ca2630275bd59f7ea7b7576497
Reviewed-on: https://go-review.googlesource.com/20088
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Static branch predictions (which guide block ordering) are
adjusted based on:
loop/not-loop (favor looping)
abnormal-exit/not (avoid panic)
call/not-call (avoid call)
ret/default (treat returns as rare)
This appears to make no difference in performance of real
code, meaning the compiler itself. The earlier version of
this has been stripped down to help make the cost of this
only-aesthetic-on-Intel phase be as cheap as possible (we
probably want information about inner loops for improving
register allocation, but because register allocation follows
close behind this pass, conceivably the information could be
reused -- so we might do this anyway just to normalize
output).
For a ./make.bash that takes 200 user seconds, about .75
second is reported in likelyadjust (summing nanoseconds
reported with -d=ssa/likelyadjust/time ).
Upstream predictions are respected.
Includes test, limited to build on amd64 only.
Did several iterations on the debugging output to allow
some rough checks on behavior.
Debug=1 logging notes agree/disagree with earlier passes,
allowing analysis like the following:
Run on make.bash:
GO_GCFLAGS=-d=ssa/likelyadjust/debug \
./make.bash >& lkly5.log
grep 'ranch prediction' lkly5.log | wc -l
78242 // 78k predictions
grep 'ranch predi' lkly5.log | egrep -v 'agrees with' | wc -l
29633 // 29k NEW predictions
grep 'disagrees' lkly5.log | wc -l
444 // contradicted 444 times
grep '< exit' lkly5.log | wc -l
10212 // 10k exit predictions
grep '< exit' lkly5.log | egrep 'disagrees' | wc -l
5 // 5 contradicted by previous prediction
grep '< exit' lkly5.log | egrep -v 'agrees' | wc -l
702 // 702-5 redundant with previous prediction
grep '< call' lkly5.log | egrep -v 'agrees' | wc -l
16699 // 16k new call predictions
grep 'stay in loop' lkly5.log | egrep -v 'agrees' | wc -l
3951 // 4k new "remain in loop" predictions
Fixes#11451.
Change-Id: Iafb0504f7030d304ef4b6dc1aba9a5789151a593
Reviewed-on: https://go-review.googlesource.com/19995
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Add a blank line before the "package ssa" lines so the "autogenerated
don't edit" comments don't end up in godoc output.
Change-Id: I82bf90d52d426ce1a8e21483fc8f47b3689259c7
Reviewed-on: https://go-review.googlesource.com/20086
Reviewed-by: Keith Randall <khr@golang.org>
* This is a very basic form of straight line strength reduction.
* Removes one multiplication from a[b].c++; a[b+1].c++
* It increases pressure on the register allocator because
CSE creates more copies of the multiplication sizeof(a[0])*b.
Change-Id: I686a18e9c24cc6f8bdfa925713afed034f7d36d0
Reviewed-on: https://go-review.googlesource.com/20091
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Use only reflect.TypeOf to detect if argument is a string.
The wasString return is only needed in doPrint with the 'v' verb.
This type of string detection is handled correctly by reflect.TypeOf
which is used already in doPrint for identifying a string argument.
Remove now obsolete wasString computations and return values.
Change-Id: Iea2de7ac0f5c536a53eec63f7e679d628f5af8dc
Reviewed-on: https://go-review.googlesource.com/19976
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Also, relocate related const and type definitions from go.go.
Change-Id: Ieb9b672da8dd510ca67022b4f7ae49a778a56579
Reviewed-on: https://go-review.googlesource.com/20080
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Keith Randall <khr@golang.org>
Add writeback code to each return location which copies
the final result back to the correct stack location.
Cgo plays tricky games by taking the address of a
in f(a int) (b int) and then using that address to
modify b. So for cgo-generated Go code, disable the
SSAing of output args.
Update #14511
Change-Id: I95cba727d53699d31124eef41db0e03935862be9
Reviewed-on: https://go-review.googlesource.com/19988
Reviewed-by: Todd Neal <todd@tneal.org>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
In best of 10, linking cmd/go shows a ~10% improvement.
tip: real 0m1.152s user 0m1.005s
this: real 0m1.065s user 0m0.924s
Change-Id: I303a20b94332feaedc1033c453247a0e4c05c843
Reviewed-on: https://go-review.googlesource.com/19978
Reviewed-by: David Crawshaw <crawshaw@golang.org>
It gets rewritten to an xor by the linker also.
Change-Id: Iae35130325d41bd1a09b7e971190cae6f4e17fac
Reviewed-on: https://go-review.googlesource.com/20058
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The object file reader in cmd/link reads the symbol name into a scratch
[]byte, converts it to a string, and then does a substring replacement.
Instead, this CL does the replacement on the []byte into the scratch
space and then creates the final string.
Linking godoc without DWARF, best of ten, shows a ~10% improvement.
tip: real 0m1.099s user 0m1.541s
this: real 0m0.990s user 0m1.280s
This is part of an attempt to make suffixarray string deduping
come out as a wash, but it's not there yet:
cl/19987: real 0m1.335s user 0m1.794s
cl/19987+this: real 0m1.225s user 0m1.540s
Change-Id: Idf061fdfbd7f08aa3a1f5933d3f111fdd1659210
Reviewed-on: https://go-review.googlesource.com/20025
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The Cpos function is used frequently (at least once per symbol) and
it is implemented with the seek syscall. Instead, track current
output offset and use it.
Building the godoc binary with DWARF, best of ten:
tip: real 0m1.287s user 0m1.573s
this: real 0m1.208s user 0m1.555s
Change-Id: I068148695cd6b4d32cd145db25e59e6f6bae6945
Reviewed-on: https://go-review.googlesource.com/20055
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
