Don't write back parts of a slicing operation if they
are unchanged from the source of the slice. For example:
x.s = x.s[0:5] // don't write back pointer or cap
x.s = x.s[:5] // don't write back pointer or cap
x.s = x.s[:5:7] // don't write back pointer
There is more to be done here, for example:
x.s = x.s[:len(x.s):7] // don't write back ptr or len
This CL can't handle that one yet.
Fixes#14855
Change-Id: Id1e1a4fa7f3076dc1a76924a7f1cd791b81909bb
Reviewed-on: https://go-review.googlesource.com/20954
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
For the following example, but there are a few more in the stdlib:
func histogram(b []byte, h *[256]int32) {
for _, t := range b {
h[t]++
}
}
Change-Id: I56615f341ae52e02ef34025588dc6d1c52122295
Reviewed-on: https://go-review.googlesource.com/20924
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Allow inlining of functions with switch statements as long as they don't
contain a break or type switch.
Fixes#13071
Change-Id: I057be351ea4584def1a744ee87eafa5df47a7f6d
Reviewed-on: https://go-review.googlesource.com/20824
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Converting a big.Float value x to a float32/64 value did not correctly
round x up to the smallest denormal float32/64 if x was smaller than the
smallest denormal float32/64, but larger than 0.5 of a smallest denormal
float32/64.
Handle this case explicitly and simplify some code in the turn.
For #14651.
Change-Id: I025e24bf8f0e671581a7de0abf7c1cd7e6403a6c
Reviewed-on: https://go-review.googlesource.com/20816
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
The inserted early bound checks cause the slice
to expand beyond the original length of the slice.
Change-Id: Ib38891605f4a9a12d3b9e2071a5f77640b083d2d
Reviewed-on: https://go-review.googlesource.com/20981
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
MOVSB is quite a bit faster for unaligned moves.
Possibly we should use MOVSB all of the time, but Intel folks
say it might be a bit faster to use MOVSQ on some processors
(but not any I have access to at the moment).
benchmark old ns/op new ns/op delta
BenchmarkMemmove4096-8 93.9 93.2 -0.75%
BenchmarkMemmoveUnalignedDst4096-8 256 151 -41.02%
BenchmarkMemmoveUnalignedSrc4096-8 175 90.5 -48.29%
Fixes#14630
Change-Id: I568e6d6590eb3615e6a699fb474020596be665ff
Reviewed-on: https://go-review.googlesource.com/20293
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Left over from CL 20931.
Change-Id: I3b8dd9ef748bcbf70b5118da28135aaa1e5ba3a8
Reviewed-on: https://go-review.googlesource.com/20955
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Minux Ma <minux@golang.org>
Constant comparisons against 0 are reasonably common.
Special-case and avoid allocating a new zero value each time.
Change-Id: I6c526c8ab30ef7f0fef59110133c764b7b90ba05
Reviewed-on: https://go-review.googlesource.com/20956
Reviewed-by: Alan Donovan <adonovan@google.com>
Also give them more idiomatic Go names. Adding godocs is outside the
scope of this CL. (Besides, the method names almost all directly
parallel an underlying math/big.Int or math/big.Float method.)
CL prepared mechanically with sed (for rewriting mpint.go/mpfloat.go)
and gofmt (for rewriting call sites).
Passes toolstash -cmp.
Change-Id: Id76f4aee476ba740f48db33162463e7978c2083d
Reviewed-on: https://go-review.googlesource.com/20909
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Fixed bug that slipped probably slipped in after rebasing and
explain why it failed on nacl/netbsd/plan9, which set default
maxparallelism to 1.
Change-Id: I4d59682fb2843d138b320334189f53fcdda5b2f6
Reviewed-on: https://go-review.googlesource.com/20980
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The Linux ABI takes arguments in a different order on s390x.
Change-Id: Ic9cfcc22a5ea3d8ef77d4dd0b915fc266ff3e5f7
Reviewed-on: https://go-review.googlesource.com/20960
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Minimum architecture of z196 required so that GCC can assemble
gcc_s390x.S in runtime/cgo.
Change-Id: I603ed2edd39f826fb8193740ece5bd11d18c3dc5
Reviewed-on: https://go-review.googlesource.com/20876
Reviewed-by: Ian Lance Taylor <iant@golang.org>
It was just a funny way of saying len(Ctxt.Allsym) by now.
Change-Id: Iff75e73c9f7ec4ba26cfef479bbd05d7dcd172f5
Reviewed-on: https://go-review.googlesource.com/20973
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Nothing cares about it.
I did this after looking at the memprof output, but it helps performance a bit:
name old s/op new s/op delta
LinkCmdGo 0.44 ± 3% 0.43 ± 3% -2.20% (p=0.000 n=94+90)
LinkJuju 3.98 ± 5% 3.94 ± 5% -1.19% (p=0.000 n=100+91)
As well as MaxRSS (i.e. what /usr/bin/time -f '%M' prints):
name old MaxRSS new MaxRSS delta
LinkCmdGo 130k ± 0% 120k ± 3% -7.79% (p=0.000 n=79+90)
LinkJuju 862k ± 6% 827k ± 8% -4.01% (p=0.000 n=100+99)
Change-Id: I6306b7b3369576a688659e2ecdb0815b4152ae96
Reviewed-on: https://go-review.googlesource.com/20972
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
An instruction consisting of all 0s causes an illegal instruction
signal on s390x. Since 0s are the default in this test this CL just
makes it explicit.
Change-Id: Id6e060eed1a588f4b10a4e4861709fcd19b434ac
Reviewed-on: https://go-review.googlesource.com/20962
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Debugasm can never be set in cmd/link, so delete it and the code it enables.
Change-Id: If828db0b09f1a9e512dc660ac2750657a769094c
Reviewed-on: https://go-review.googlesource.com/20971
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This expression in readsym:
dup != nil && len(dup.P) > 0 && strings.HasPrefix(s.Name, "gclocals·")
can never be true: if dup != nil, then s.Name is ".dup" (and this is not new:
the same broken logic is present in 1.4, at least). Delete the whole block.
Change-Id: I33b14d9a82b292116d6fd79d22b38e3842501317
Reviewed-on: https://go-review.googlesource.com/20970
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The obj.Nocache helper was only used by the arm back end, move it there.
Change-Id: I5c9faf995499991ead1f3d8c8ffc3b6af7346876
Reviewed-on: https://go-review.googlesource.com/20868
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Add a special helper for its one external use.
This is in preparation for an upcoming CL.
Passes toolstash -cmp / buildall.
Change-Id: I9d3463792afe220cc4bc89269bdecf0279abd281
Reviewed-on: https://go-review.googlesource.com/20933
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
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>
'b' is a standard verb for floating point values. The runes like '+'
and '#' are called "flags" by package fmt's documentation. The flag
'-' controls left/right justification, not anything related to signs.
Change-Id: Ia9cf81b002df373f274ce635fe09b5bd0066aa1c
Reviewed-on: https://go-review.googlesource.com/20930
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Another object file change, gives a reasonable improvement:
name old s/op new s/op delta
LinkCmdGo 0.46 ± 3% 0.44 ± 9% -3.34% (p=0.000 n=98+82)
LinkJuju 4.09 ± 4% 3.92 ± 5% -4.30% (p=0.000 n=98+99)
I guess the data section could be mmap-ed instead of read, I haven't tried
that.
Change-Id: I959eee470a05526ab1579e3f5d3ede41c16c954f
Reviewed-on: https://go-review.googlesource.com/20928
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
In tests TransportPersistConnLeak and TransportPersistConnLeakShortBody,
there's a fixed wait time (100ms and 400ms respectively) to allow
goroutines to exit after CloseIdleConnections is called. This
is sometimes too short on a slow host running many simultaneous
tests.
This CL replaces the fixed sleep in each test with a sequence of
shorter sleeps, testing the number of remaining goroutines until
it reaches the threshold or an overall time limit of 500ms expires.
This prevents some failures in the plan9_arm builder, while reducing
the test time on faster machines.
Fixes#14887
Change-Id: Ia5c871062df139e2667cdfb2ce8283e135435318
Reviewed-on: https://go-review.googlesource.com/20922
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
For a long time varexpr has handled ODOT incorrectly: it has always
returned false. Before https://golang.org/cl/20890 this has been
because an ODOT had a Right field with an ONAME with no Class, for which
varexpr returns false. CL 20890 preserved the behavior of varexpr for
ODOT, so that the change would pass toolstash -cmp.
This CL fixes varexpr so that ODOT can return true in some cases. This
breaks toolstash -cmp. While the changed compiler allocates temporary
variables in a different order, I have not been able to find any
examples where the generated code is different, other than using
different stack offsets and, in some cases, registers. It seems that
other parts of the compiler will force the ODOT into a temporary anyhow.
Still, this change is clearly correct, and is a minor compiler cleanup.
Change-Id: I71506877aa3c13966bb03c281aa16271ee7fe80a
Reviewed-on: https://go-review.googlesource.com/20907
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Historically ODOT and friends have been considered to cost an extra
budget point when deciding whether they should be inlined, because they
had an ONAME node that represented the name to the right of the dot.
This doesn't really make sense, as in general that symbol does not add
any extra instructions; it just affects the offset of the load or store
instruction. And the ONAME node is gone now. So, remove the extra
cost.
This does not pass toolstash -cmp, as it changes inlining decisions.
For example, mspan.init in runtime/mheap.go is now considered to be an
inlining candidate.
Change-Id: I5ad27f08c66fd5daa4c8472dd0795df989183f5e
Reviewed-on: https://go-review.googlesource.com/20891
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reduces size of archives in pkg/linux_amd64 by 3% from 41.5MB to 40.2MB
Change-Id: Id64ca7995de8dd84c9e7ce1985730927cf4bfd66
Reviewed-on: https://go-review.googlesource.com/20912
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Deduplicate the verb switch for signed and unsigned integer formatting.
Make names of integer related functions consistent
with names of other fmt functions.
Consolidate basic integer tests.
Change-Id: I0c19c24f1c2c06a3b1a4d7d377dcdac3b36bb0f5
Reviewed-on: https://go-review.googlesource.com/20831
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
In golang.org/cl/20602, I changed the semantics of Eqtype to stop
checking the receiver parameters for type equality, and pushed this
responsibility to addmethod (the only Eqtype caller that cared).
However, I accidentally made the check stricter by making it start
requiring that receiver names were identical.
In general, this is a non-problem because the receiver names in export
data will always match the original source. But running
GO_GCFLAGS=-newexport ./all.bash at one point tries to load both old
and new format export data for package sync, which reveals the
problem. (See golang.org/issue/14877 for details.)
Easy fix: just check the receiver type for type equality in addmethod,
instead of the entire receiver parameter list.
Fixes#14877.
Change-Id: If10b79f66ba58a1b7774622b4fbad1916aba32f1
Reviewed-on: https://go-review.googlesource.com/20906
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Most 64-bit x86 ops can only take a signed 32-bit constant.
Clean up our rewrite rules to enforce this restriction.
Modify the assembler to fail if the offset does not fit
in the instruction.
That last check triggers a few times on weird testing code.
Suppress those errors if the compiler itself generated errors.
Fixes#14862
Change-Id: I76559af035b38483b1e59621a8029fc66b3a5d1e
Reviewed-on: https://go-review.googlesource.com/20815
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Changes the integer function to restore the original f.zero value
and therefore padding type before returning.
Change-Id: I456449259a3d39bd6d62e110553120c31ec63f23
Reviewed-on: https://go-review.googlesource.com/20512
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
handleMethods can format Error() and String() directly as its known
these return strings that can be directly printed using fmtString.
Remove the obsolete depth argument from handleMethods.
Remove the depth argument from printArg since it is only ever
called with depth set to 0. Recursion for formatting complex
arguments is handled only by printValue which keeps track of depth.
Change-Id: I4c4be588751de12ed999e7561a51bc168eb9eb2d
Reviewed-on: https://go-review.googlesource.com/20911
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
The Node type ODOT and its variants all represent a selector, with a
simple name to the right of the dot. Before this change this was
represented by using an ONAME Node in the Right field. This ONAME node
served no useful purpose. This CL changes these Node types to store the
symbol in the Sym field instead, thus not requiring allocating a Node
for each selector.
When compiling x/tools/go/types this CL eliminates nearly 5000 calls to
newname and reduces the total number of Nodes allocated by about 6.6%.
It seems to cut compilation time by 1 to 2 percent.
Getting this right was somewhat subtle, and I added two dubious changes
to produce the exact same output as before. One is to ishairy in
inl.go: the ONAME node increased the cost of ODOT and friends by 1, and
I retained that, although really ODOT is not more expensive than any
other node. The other is to varexpr in walk.go: because the ONAME in
the Right field of an ODOT has no class, varexpr would always return
false for an ODOT, although in fact for some ODOT's it seemingly ought
to return true; I added an && false for now. I will send separate CLs,
that will break toolstash -cmp, to clean these up.
This CL passes toolstash -cmp.
Change-Id: I4af8a10cc59078c436130ce472f25abc3a9b2f80
Reviewed-on: https://go-review.googlesource.com/20890
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Consider functions with an ODCLCONST for inlining and modify exprfmt to
ignore those nodes when exporting. Don't add symbols to the export list
if there is no definition. This occurs when OLITERAL symbols are looked
up via Pkglookup for non-exported symbols.
Fixes#7655
Change-Id: I1de827850f4c69e58107447314fe7433e378e069
Reviewed-on: https://go-review.googlesource.com/20773
Run-TryBot: Todd Neal <todd@tneal.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
