cmd/link: external linking can fail on Solaris 11.2+
Workaround external linking issues encountered on Solaris 11.2+ due to
the go.o object file being created with a NULL STT_FILE symtab entry by
using a placeholder name.
Fixes #14957
Change-Id: I89c501b4c548469f3c878151947d35588057982b
Reviewed-on: https://go-review.googlesource.com/21636 Reviewed-by: David Crawshaw <crawshaw@golang.org>
1. Parse out version from trace header.
2. Restore handling of 1.5 traces.
3. Restore optional symbolization of traces.
4. Add some canned 1.5 traces for regression testing
(http benchmark trace, runtime/trace stress traces,
plus one with broken timestamps).
Keith Randall [Fri, 1 Apr 2016 04:24:10 +0000 (21:24 -0700)]
cmd/compile: fix naming of decomposed structs
When a struct is SSAable, we will name its component parts
by their field names. For example,
type T struct {
a, b, c int
}
If we ever need to spill a variable x of type T, we will
spill its individual components to variables named x.a, x.b,
and x.c.
Change-Id: I857286ff1f2597f2c4bbd7b4c0b936386fb37131
Reviewed-on: https://go-review.googlesource.com/21389 Reviewed-by: David Chase <drchase@google.com>
Shahar Kohanim [Thu, 7 Apr 2016 15:00:57 +0000 (18:00 +0300)]
cmd/link: symbol generation optimizations
After making dwarf generation backed by LSyms there was a performance regression
of about 10%. These changes make on the fly symbol generation faster and
are meant to help mitigate that.
name old secs new secs delta
LinkCmdGo 0.55 ± 9% 0.53 ± 8% -4.42% (p=0.000 n=100+99)
name old MaxRSS new MaxRSS delta
LinkCmdGo 152k ± 6% 149k ± 3% -1.99% (p=0.000 n=99+97)
Change-Id: Iacca3ec924ce401aa83126bc0b10fe89bedf0ba6
Reviewed-on: https://go-review.googlesource.com/21733
Run-TryBot: Shahar Kohanim <skohanim@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Crawshaw <crawshaw@golang.org>
net/http/pprof: accept fractional seconds in trace handler
For heavily loaded servers, even 1 second of trace is too large
to process with the trace viewer; using a float64 here allows
fetching /debug/pprof/trace?seconds=0.1.
Michael Munday [Mon, 11 Apr 2016 01:58:37 +0000 (21:58 -0400)]
cmd/compile/internal/gc: refactor cgen_div
This commit adds two new functions to cgen.go: hasHMUL64 and
hasRROTC64. These are used to determine whether or not an
architecture supports the instructions needed to perform an
optimization in cgen_div.
This commit should not affect existing architectures (although it
does add s390x to the new functions). However, since most
architectures support HMUL the hasHMUL64 function could be
modified to enable most of the optimizations in cgen_div on those
platforms.
Jeremy Jackins [Thu, 7 Apr 2016 06:42:35 +0000 (15:42 +0900)]
runtime: remove remaining references to TheChar
After mdempsky's recent changes, these are the only references to
"TheChar" left in the Go tree. Without the context, and without
knowing the history, this is confusing.
Also rename sys.TheGoos and sys.TheGoarch to sys.GOOS
and sys.GOARCH.
Also change the heap dump format to include sys.GOARCH
rather than TheChar, which is no longer a concept.
Updates #15169 (changes heapdump format)
Change-Id: I3e99eeeae00ed55d7d01e6ed503d958c6e931dca
Reviewed-on: https://go-review.googlesource.com/21647 Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Martin Möhrmann [Sun, 10 Apr 2016 15:32:35 +0000 (17:32 +0200)]
runtime: speed up makeslice by avoiding divisions
Only compute the number of maximum allowed elements per slice once.
name old time/op new time/op delta
MakeSlice-2 55.5ns ± 1% 45.6ns ± 2% -17.88% (p=0.000 n=99+100)
Change-Id: I951feffda5d11910a75e55d7e978d306d14da2c5
Reviewed-on: https://go-review.googlesource.com/21801
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Andrew Gerrand [Fri, 8 Apr 2016 05:39:32 +0000 (15:39 +1000)]
text/template: emit field error over nil pointer error where appropriate
When evaluating "{{.MissingField}}" on a nil *T, Exec returns
"can't evaluate field MissingField in type *T" instead of
"nil pointer evaluating *T.MissingField".
Fixes golang/go#15125
Change-Id: I6e73f61b8a72c694179c1f8cdc808766c90b6f57
Reviewed-on: https://go-review.googlesource.com/21705 Reviewed-by: Rob Pike <r@golang.org>
Instead of being a hint, resultInArg0 is now enforced by regalloc.
This allows us to delete all the code from amd64/ssa.go which
deals with converting from a semantically three-address instruction
into some copies plus a two-address instruction.
Instead of spilling newlen, recalculate it.
This removes a spill from the fast path,
at the cost of a cheap recalculation
on the (rare) growth path.
This uses 8 bytes less of stack space.
It generates two more bytes of code,
but that is due to suboptimal register allocation;
see far below.
Runtime append microbenchmarks are all over the map,
presumably due to incidental code movement.
Sample code:
func s(b []byte) []byte {
b = append(b, 1, 2, 3)
return b
}
Observe that in the following sequence,
we should use DX directly instead of using
CX as a temporary register, which would make
the new code a strict improvement on the old:
Change-Id: I9e927a2f604213338b4572f1a32d0247c58bdc60
Reviewed-on: https://go-review.googlesource.com/21798 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Sysmon critically depends on system timer resolution for retaking
of Ps blocked in system calls. See #14790 for an example
of a program where execution time goes from 2ms to 30ms if
timeBeginPeriod(1) is not used.
We can remove timeBeginPeriod(1) when we support UMS (#7876).
Dave Cheney [Fri, 8 Apr 2016 09:30:41 +0000 (19:30 +1000)]
cmd: remove bio.BufReader and bio.BufWriter
bio.BufReader was never used.
bio.BufWriter was used to wrap an existing io.Writer, but the
bio.Writer returned would not be seekable, so replace all occurences
with bufio.Reader instead.
David Chase [Fri, 8 Apr 2016 17:33:43 +0000 (13:33 -0400)]
cmd/compile: insert instrumentation more carefully in racewalk
Be more careful about inserting instrumentation in racewalk.
If the node being instrumented is an OAS, and it has a non-
empty Ninit, then append instrumentation to the Ninit list
rather than letting it be inserted before the OAS (and the
compilation of its init list). This deals with the case that
the Ninit list defines a variable used in the RHS of the OAS.
This makes traces self-contained and simplifies trace workflow
in modern cloud environments where it is simpler to reach
a service via HTTP than to obtain the binary.
Change-Id: I6ff3ca694dc698270f1e29da37d5efaf4e843a0d
Reviewed-on: https://go-review.googlesource.com/21732
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Rob Pike [Thu, 7 Apr 2016 03:19:47 +0000 (20:19 -0700)]
io: change the name of ReadAtSizer to SizedReaderAt
This is a proposal. The old name is pretty poor. The new one describes
it better and may be easier to remember. It does not start with Read,
though I think that inconsistency is worthwhile.
Joe Tsai [Thu, 31 Mar 2016 23:05:23 +0000 (16:05 -0700)]
bytes, string: add Reset method to Reader
Currently, there is no easy allocation-free way to turn a
[]byte or string into an io.Reader. Thus, we add a Reset method
to bytes.Reader and strings.Reader to allow the reuse of these
Readers with another []byte or string.
This is consistent with the fact that many standard library io.Readers
already support a Reset method of some type:
bufio.Reader
flate.Reader
gzip.Reader
zlib.Reader
debug/dwarf.LineReader
bytes.Buffer
crypto/rc4.Cipher
Alexandru Moșoi [Tue, 5 Apr 2016 21:32:49 +0000 (23:32 +0200)]
cmd/compile: fold CMPconst and SHR
Fold the comparison when the SHR result is small.
Useful for:
- murmur mix like hashing where higher bits are desirable, i.e. hash = uint32(i * C) >> 18
- integer log2 via DeBruijn sequence: http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogDeBruijn
Change-Id: If70ae18cb86f4cc83ab6213f88ced03cc4986156
Reviewed-on: https://go-review.googlesource.com/21514
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
Richard Miller [Wed, 6 Apr 2016 17:58:22 +0000 (18:58 +0100)]
runtime/pprof: make TestBlockProfile less timing dependent
The test for profiling of channel blocking is timing dependent,
and in particular the blockSelectRecvAsync case can fail on a
slow builder (plan9_arm) when many tests are run in parallel.
The child goroutine sleeps for a fixed period so the parent
can be observed to block in a select call reading from the
child; but if the OS process running the parent goroutine is
delayed long enough, the child may wake again before the
parent has reached the blocking point. By repeating the test
three times, the likelihood of a blocking event is increased.
Dave Cheney [Wed, 6 Apr 2016 21:29:22 +0000 (07:29 +1000)]
runtime: merge lfstack{Pack,Unpack} into one file
Merge the remaining lfstack{Pack,Unpack} implemetations into one file.
unsafe.Sizeof(uintptr(0)) == 4 is a constant comparison so this branch
folds away at compile time.
Dmitry confirmed that the upper 17 bits of an address will be zero for a
user mode pointer, so there is no need to sign extend on amd64 during
unpack, so we can reuse the same implementation as all othe 64 bit
archs.
Change-Id: I99f589416d8b181ccde5364c9c2e78e4a5efc7f1
Reviewed-on: https://go-review.googlesource.com/21597
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Minux Ma <minux@golang.org>
Matthew Dempsky [Thu, 7 Apr 2016 01:54:17 +0000 (18:54 -0700)]
cmd/compile, cmd/link: eliminate uses of ArchFamily in error messages
Two of these error messages are already dead code: cmd/compile.main
and cmd/link.main already switch on $GOARCH, ensuring it must be a
prefix of the sys.Arch.Family.
The error message about uncompiled Go source files can be just be
simplified: anyone who's manually constructing Go object file archives
probably knows what tool to use to compile Go source files.
Matthew Dempsky [Wed, 6 Apr 2016 19:01:40 +0000 (12:01 -0700)]
cmd: add new common architecture representation
Information about CPU architectures (e.g., name, family, byte
ordering, pointer and register size) is currently redundantly
scattered around the source tree. Instead consolidate the basic
information into a single new package cmd/internal/sys.
Also, introduce new sys.I386, sys.AMD64, etc. names for the constants
'8', '6', etc. and replace most uses of the latter. The notable
exceptions are a couple of error messages that still refer to the old
char-based toolchain names and function reltype in cmd/link.
Passes toolstash/buildall.
Change-Id: I8a6f0cbd49577ec1672a98addebc45f767e36461
Reviewed-on: https://go-review.googlesource.com/21623 Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Ryan Brown [Mon, 14 Mar 2016 16:23:04 +0000 (09:23 -0700)]
cmd/link: generate DWARF info using symbols
This updates dwarf.go to generate debug information as symbols
instead of directly writing to the output file. This should make
it easier to move generation of some of the debug info into the compiler.
Change-Id: Id2358988bfb689865ab4d68f82716f0676336df4
Reviewed-on: https://go-review.googlesource.com/20679 Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Dave Cheney [Wed, 6 Apr 2016 08:43:23 +0000 (18:43 +1000)]
runtime: remove unused return value from lfstackUnpack
None of the two places that call lfstackUnpack use the second argument.
This simplifies a followup CL that merges the lfstack{Pack,Unpack}
implementations.
Alexandru Moșoi [Mon, 4 Apr 2016 17:23:41 +0000 (19:23 +0200)]
cmd/compile: replaces ANDQ with MOV?ZX
Where possible replace ANDQ with MOV?ZX.
Takes care that we don't regress wrt bounds checking,
for example [1000]int{}[i&255].
According to "Intel 64 and IA-32 Architectures Optimization Reference
Manual" Section: "3.5.1.13 Zero-Latency MOV Instructions"
MOV?ZX instructions have zero latency on newer processors.
Many of Type's fields are etype-specific.
This CL organizes them into their own auxiliary types,
duplicating a few fields as necessary,
and adds an Extra field to hold them.
It also sorts the remaining fields for better struct packing.
It also improves documentation for most fields.
This reduces the size of Type at the cost of some extra allocations.
There's no CPU impact; memory impact below.
It also makes the natural structure of Type clearer.
Passes toolstash -cmp on all architectures.
Ideas for future work in this vein:
(1) Width and Align probably only need to be
stored for Struct and Array types.
The refactoring to accomplish this would hopefully
also eliminate TFUNCARGS and TCHANARGS entirely.
(2) Maplineno is sparsely used and could probably better be
stored in a separate map[*Type]int32, with mapqueue updated
to store both a Node and a line number.
(3) The Printed field may be removable once the old (non-binary)
importer/exported has been removed.
(4) StructType's fields field could be changed from *[]*Field to []*Field,
which would remove a common allocation.
(5) I believe that Type.Nod can be moved to ForwardType. Separate CL.
Richard Miller [Wed, 6 Apr 2016 17:42:14 +0000 (18:42 +0100)]
test: make goprint.go wait for goroutine termination
Test goprint.go sometimes failed on a slow builder (plan9_arm)
because of timing dependency. Instead of sleeping for a fixed
time to allow the child goroutine to finish, wait explicitly for
child termination by calling runtime.NumGoroutine until the
returned value is 1.
Robert Griesemer [Wed, 6 Apr 2016 17:49:12 +0000 (10:49 -0700)]
cmd/gofmt: make gofmt -s simplify slices in presence of dot-imports
A dot-import cannot possibly introduce a `len` function since that
function would not be exported (it's lowercase). Furthermore, the
existing code already (incorrectly) assumed that there was no other
`len` function in another file of the package. Since this has been
an ok assumption for years, let's leave it, but remove the dot-import
restriction.
Fixes #15153.
Change-Id: I18fbb27acc5a5668833b4b4aead0cca540862b52
Reviewed-on: https://go-review.googlesource.com/21613 Reviewed-by: Alan Donovan <adonovan@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
icmd/vet: improved checking for variadic Println-like functions
- Automatically determine the first argument to check.
- Skip checking matching non-variadic functions.
- Skip checking matching functions accepting non-interface{}
variadic arguments.
- Removed fragile 'magic' code for special cases such as math.Log
and error interface.
Fixes #15067
Fixes #15099
Change-Id: Ib313557f18b12b36daa493f4b02c598b9503b55b
Reviewed-on: https://go-review.googlesource.com/21513
Run-TryBot: Rob Pike <r@golang.org> Reviewed-by: Rob Pike <r@golang.org>
Matthew Dempsky [Wed, 6 Apr 2016 06:01:10 +0000 (23:01 -0700)]
cmd/link: eliminate a bunch of open coded elf64/rela switches
We already have variables to track whether the target platform is
64-bit vs 32-bit or RELA vs REL, so no point in repeating the list of
obscure architecture characters everywhere.
Passes toolstash/buildall.
Change-Id: I6a07f74188ac592ef229a7c65848a9ba93013cdb
Reviewed-on: https://go-review.googlesource.com/21569
Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Keith Randall [Fri, 1 Apr 2016 18:05:30 +0000 (11:05 -0700)]
cmd/compile: fix x=x assignments
No point in doing anything for x=x assignments.
In addition, skipping these assignments prevents generating:
VARDEF x
COPY x -> x
which is bad because x is incorrectly considered
dead before the vardef.