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2025-10-29internal/itoa, internal/runtime/strconv: deleteRuss Cox
Replaced by internal/strconv. Change-Id: I0656a9ad5075e60339e963fbae7d194d2f3e16be Reviewed-on: https://go-review.googlesource.com/c/go/+/716001 Reviewed-by: David Chase <drchase@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2025-09-02runtime: add comment for concatstring2Youlin Feng
People always want to remove concatstring{2,3,4,5} for performance, but we keep them to make the binary smaller. So, add a comment to document why. Updates #65020 Change-Id: I819976b700d45ce4d0846bf4481b2654b85708da Reviewed-on: https://go-review.googlesource.com/c/go/+/700095 Auto-Submit: Keith Randall <khr@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com>
2025-05-19runtime: move atoi to internal/runtime/strconvMichael Pratt
Moving to a smaller package allows its use in other internal/runtime packages. This isn't internal/strconvlite since it can't be used directly by strconv. For #73193. Change-Id: I6a6a636c9c8b3f06b5fd6c07fe9dd5a7a37d1429 Reviewed-on: https://go-review.googlesource.com/c/go/+/672697 Reviewed-by: Michael Knyszek <mknyszek@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Auto-Submit: Michael Pratt <mpratt@google.com>
2025-02-25cmd/compile, runtime: optimize concatbytesCuong Manh Le
CL 527935 optimized []byte(string1 + string2) to use runtime.concatbytes to prevent concatenating of strings before converting to slices. However, the optimization is implemented without allowing temporary buffer for slice on stack, causing un-necessary allocations. To fix this, optimize concatbytes to use temporary buffer if the result string length fit to the buffer size. Fixes #71943 Change-Id: I1d3c374cd46aad8f83a271b8a5ca79094f9fd8db Reviewed-on: https://go-review.googlesource.com/c/go/+/652395 Reviewed-by: Keith Randall <khr@google.com> Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com>
2024-10-29strings,bytes: use result of copy in subsequent slicingKeith Randall
This can get rid of a bounds check. Followup to CL 622240. Change-Id: I9d0a2c0408b8d274c46136d32d7a5fb09b4aad1c Reviewed-on: https://go-review.googlesource.com/c/go/+/622955 Reviewed-by: David Chase <drchase@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
2024-09-17runtime: move getcallerpc to internal/runtime/sysMichael Pratt
Moving these intrinsics to a base package enables other internal/runtime packages to use them. For #54766. Change-Id: I0b3eded3bb45af53e3eb5bab93e3792e6a8beb46 Reviewed-on: https://go-review.googlesource.com/c/go/+/613260 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2024-09-10cmd/compile: optimize []byte(string1 + string2)Paschalis Tsilias
This CL optimizes the compilation of string-to-bytes conversion in the case of string additions. Fixes #62407 Change-Id: Ic47df758478e5d061880620025c4ec7dbbff8a64 Reviewed-on: https://go-review.googlesource.com/c/go/+/527935 Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Keith Randall <khr@golang.org> Auto-Submit: Keith Randall <khr@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@google.com> Reviewed-by: Tim King <taking@google.com>
2024-09-06runtime: remove cloudwego/frugal unused linkname from commentKyle Xiao
frugal no longer uses these methods from next Go version Fixes #69222 Change-Id: Ie71de0752cabef7d5584d3392d6e5920ba742350 Reviewed-on: https://go-review.googlesource.com/c/go/+/609918 Auto-Submit: Ian Lance Taylor <iant@google.com> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-05-23all: document legacy //go:linkname for modules with ≥200 dependentsRuss Cox
Ignored these linknames which have not worked for a while: github.com/xtls/xray-core: context.newCancelCtx removed in CL 463999 (Feb 2023) github.com/u-root/u-root: funcPC removed in CL 513837 (Jul 2023) tinygo.org/x/drivers: net.useNetdev never existed For #67401. Change-Id: I9293f4ef197bb5552b431de8939fa94988a060ce Reviewed-on: https://go-review.googlesource.com/c/go/+/587576 Auto-Submit: Russ Cox <rsc@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-05-17runtime: make use of stringslite.{HasPrefix, HasSuffix}Jes Cok
Change-Id: I7461a892e1591e3bad876f0a718a99e6de2c4659 Reviewed-on: https://go-review.googlesource.com/c/go/+/585435 Reviewed-by: Michael Knyszek <mknyszek@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
2024-05-15cmd/link: disallow pull-only linknamesCherry Mui
As mentioned in CL 584598, linkname is a mechanism that, when abused, can break API integrity and even safety of Go programs. CL 584598 is a first step to restrict the use of linknames, by implementing a blocklist. This CL takes a step further, tightening up the restriction by allowing linkname references ("pull") only when the definition side explicitly opts into it, by having a linkname on the definition (possibly to itself). This way, it is at least clear on the definition side that the symbol, despite being unexported, is accessed outside of the package. Unexported symbols without linkname can now be actually private. This is similar to the symbol visibility rule used by gccgo for years (which defines unexported non-linknamed symbols as C static symbols). As there can be pull-only linknames in the wild that may be broken by this change, we currently only enforce this rule for symbols defined in the standard library. Push linknames are added in the standard library to allow things build. Linkname references to external (non-Go) symbols are still allowed, as their visibility is controlled by the C symbol visibility rules and enforced by the C (static or dynamic) linker. Assembly symbols are treated similar to linknamed symbols. This is controlled by -checklinkname linker flag, currently not enabled by default. A follow-up CL will enable it by default. Change-Id: I07344f5c7a02124dbbef0fbc8fec3b666a4b2b0e Reviewed-on: https://go-review.googlesource.com/c/go/+/585358 LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Than McIntosh <thanm@google.com> Reviewed-by: Russ Cox <rsc@golang.org>
2023-11-09runtime: implement experiment to replace heap bitmap with alloc headersMichael Anthony Knyszek
This change replaces the 1-bit-per-word heap bitmap for most size classes with allocation headers for objects that contain pointers. The header consists of a single pointer to a type. All allocations with headers are treated as implicitly containing one or more instances of the type in the header. As the name implies, headers are usually stored as the first word of an object. There are two additional exceptions to where headers are stored and how they're used. Objects smaller than 512 bytes do not have headers. Instead, a heap bitmap is reserved at the end of spans for objects of this size. A full word of overhead is too much for these small objects. The bitmap is of the same format of the old bitmap, minus the noMorePtrs bits which are unnecessary. All the objects <512 bytes have a bitmap less than a pointer-word in size, and that was the granularity at which noMorePtrs could stop scanning early anyway. Objects that are larger than 32 KiB (which have their own span) have their headers stored directly in the span, to allow power-of-two-sized allocations to not spill over into an extra page. The full implementation is behind GOEXPERIMENT=allocheaders. The purpose of this change is performance. First and foremost, with headers we no longer have to unroll pointer/scalar data at allocation time for most size classes. Small size classes still need some unrolling, but their bitmaps are small so we can optimize that case fairly well. Larger objects effectively have their pointer/scalar data unrolled on-demand from type data, which is much more compactly represented and results in less TLB pressure. Furthermore, since the headers are usually right next to the object and where we're about to start scanning, we get an additional temporal locality benefit in the data cache when looking up type metadata. The pointer/scalar data is now effectively unrolled on-demand, but it's also simpler to unroll than before; that unrolled data is never written anywhere, and for arrays we get the benefit of retreading the same data per element, as opposed to looking it up from scratch for each pointer-word of bitmap. Lastly, because we no longer have a heap bitmap that spans the entire heap, there's a flat 1.5% memory use reduction. This is balanced slightly by some objects possibly being bumped up a size class, but most objects are not tightly optimized to size class sizes so there's some memory to spare, making the header basically free in those cases. See the follow-up CL which turns on this experiment by default for benchmark results. (CL 538217.) Change-Id: I4c9034ee200650d06d8bdecd579d5f7c1bbf1fc5 Reviewed-on: https://go-review.googlesource.com/c/go/+/437955 Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Keith Randall <khr@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-03-10runtime: create an API for unwinding inlined framesAustin Clements
We've replicated the code to expand inlined frames in many places in the runtime at this point. This CL adds a simple iterator API that abstracts this out. We also use this to try out a new idea for structuring tests of runtime internals: rather than exporting this whole internal data type and API, we write the test in package runtime and import the few bits of std we need. The idea is that, for tests of internals, it's easier to inject public APIs from std than it is to export non-public APIs from runtime. This is discussed more in #55108. For #54466. Change-Id: Iebccc04ff59a1509694a8ac0e0d3984e49121339 Reviewed-on: https://go-review.googlesource.com/c/go/+/466096 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Run-TryBot: Austin Clements <austin@google.com>
2022-11-11internal/syscall/unix: use runtime.gostring for GostringIan Lance Taylor
Under the race detector, checkptr flags uses of unsafe.Slice that result in slices that straddle multiple Go allocations. Avoid that scenario by calling existing runtime code. This fixes a failure on the darwin-.*-race builders introduced in CL 446178. Change-Id: I6e0fdb37e3c3f38d97939a8799bb4d10f519c5b9 Reviewed-on: https://go-review.googlesource.com/c/go/+/449936 Reviewed-by: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> Auto-Submit: Ian Lance Taylor <iant@golang.org>
2022-09-13runtime: replace stringStruct with unsafe.String where appropriateCuong Manh Le
Simplify the code a bit, no significant performance changes. name old time/op new time/op delta HashStringSpeed-8 9.64ns ±11% 8.91ns ± 9% -7.60% (p=0.007 n=10+10) HashStringArraySpeed-8 19.8ns ± 3% 19.5ns ± 2% ~ (p=0.085 n=10+10) MapStringKeysEight_16-8 10.7ns ± 3% 10.2ns ± 2% -4.48% (p=0.000 n=10+10) MapStringKeysEight_32-8 8.89ns ± 3% 8.71ns ± 3% ~ (p=0.082 n=9+10) MapStringKeysEight_64-8 8.84ns ± 2% 8.60ns ± 3% -2.73% (p=0.004 n=9+10) MapStringKeysEight_1M-8 8.90ns ± 3% 8.62ns ± 3% -3.15% (p=0.000 n=10+10) MapStringConversion/32/simple-8 8.62ns ± 3% 8.61ns ± 2% ~ (p=0.895 n=10+10) MapStringConversion/32/struct-8 8.53ns ± 2% 8.63ns ± 2% ~ (p=0.123 n=10+10) MapStringConversion/32/array-8 8.54ns ± 2% 8.50ns ± 1% ~ (p=0.590 n=9+9) MapStringConversion/64/simple-8 8.44ns ± 2% 8.38ns ± 2% ~ (p=0.353 n=10+10) MapStringConversion/64/struct-8 8.41ns ± 2% 8.48ns ± 2% ~ (p=0.143 n=10+10) MapStringConversion/64/array-8 8.42ns ± 2% 8.44ns ± 2% ~ (p=0.739 n=10+10) MapInterfaceString-8 13.6ns ±26% 13.6ns ±20% ~ (p=0.736 n=10+9) AppendGrowString-8 38.9ms ± 9% 40.2ms ±13% ~ (p=0.481 n=10+10) CompareStringEqual-8 3.03ns ± 2% 2.86ns ± 3% -5.58% (p=0.000 n=10+10) CompareStringIdentical-8 1.20ns ± 3% 1.01ns ± 4% -16.16% (p=0.000 n=10+10) CompareStringSameLength-8 2.11ns ± 3% 1.85ns ± 3% -12.33% (p=0.000 n=10+10) CompareStringDifferentLength-8 0.30ns ± 0% 0.30ns ± 0% ~ (p=0.508 n=10+9) CompareStringBigUnaligned-8 43.0µs ± 1% 42.8µs ± 2% ~ (p=0.165 n=10+10) CompareStringBig-8 43.2µs ± 2% 43.4µs ± 2% ~ (p=0.661 n=9+10) ConcatStringAndBytes-8 15.1ns ± 1% 14.9ns ± 1% -1.57% (p=0.001 n=8+10) SliceByteToString/1-8 2.45ns ± 2% 2.39ns ± 2% -2.64% (p=0.000 n=10+10) SliceByteToString/2-8 10.9ns ± 2% 10.8ns ± 4% ~ (p=0.060 n=10+10) SliceByteToString/4-8 11.9ns ± 0% 11.8ns ± 1% -0.97% (p=0.000 n=8+8) SliceByteToString/8-8 13.9ns ± 1% 13.9ns ± 1% +0.57% (p=0.009 n=9+9) SliceByteToString/16-8 18.0ns ± 3% 18.6ns ± 5% +2.78% (p=0.001 n=9+10) SliceByteToString/32-8 20.1ns ± 3% 20.5ns ± 5% +2.10% (p=0.034 n=10+10) SliceByteToString/64-8 24.3ns ± 3% 24.9ns ± 3% +2.28% (p=0.001 n=9+10) SliceByteToString/128-8 33.8ns ± 1% 34.5ns ± 4% ~ (p=0.264 n=8+10) Updates #54854 Change-Id: I7ce57a92c5f590fa8cb31a48969d281147eb05f1 Reviewed-on: https://go-review.googlesource.com/c/go/+/428759 Reviewed-by: hopehook <hopehook@golangcn.org> Reviewed-by: Keith Randall <khr@google.com> Run-TryBot: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-07-24runtime: fix typo in function commentsAbirdcfly
The correct word to use here is 'receive' not 'recieve' Change-Id: Ia33e2a91c1c2da6dbe479a05518dbb9b8733d20d GitHub-Last-Rev: e3c3e211dd7055d1dab8699a88d0b35c459da149 GitHub-Pull-Request: golang/go#54025 Reviewed-on: https://go-review.googlesource.com/c/go/+/419316 Reviewed-by: Keith Randall <khr@google.com> Auto-Submit: Keith Randall <khr@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Keith Randall <khr@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Keith Randall <khr@golang.org>
2022-05-19all: gofmt main repoRuss Cox
Excluding vendor and testdata. CL 384268 already reformatted most, but these slipped past. The struct in the doc comment in debug/dwarf/type.go was fixed up by hand to indent the first and last lines as well. For #51082. Change-Id: Iad020f83aafd671ff58238fe491907e85923d0c7 Reviewed-on: https://go-review.googlesource.com/c/go/+/407137 Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-05-03runtime: add byte count parser for GOMEMLIMITMichael Anthony Knyszek
This change adds a parser for the GOMEMLIMIT environment variable's input. This environment variable accepts a number followed by an optional prefix expressing the unit. Acceptable units include B, KiB, MiB, GiB, TiB, where *iB is a power-of-two byte unit. For #48409. Change-Id: I6a3b4c02b175bfcf9c4debee6118cf5dda93bb6f Reviewed-on: https://go-review.googlesource.com/c/go/+/393400 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com>
2022-04-11all: gofmt main repoRuss Cox
[This CL is part of a sequence implementing the proposal #51082. The design doc is at https://go.dev/s/godocfmt-design.] Run the updated gofmt, which reformats doc comments, on the main repository. Vendored files are excluded. For #51082. Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407 Reviewed-on: https://go-review.googlesource.com/c/go/+/384268 Reviewed-by: Jonathan Amsterdam <jba@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-04-05all: separate doc comment from //go: directivesRuss Cox
A future change to gofmt will rewrite // Doc comment. //go:foo to // Doc comment. // //go:foo Apply that change preemptively to all comments (not necessarily just doc comments). For #51082. Change-Id: Iffe0285418d1e79d34526af3520b415a12203ca9 Reviewed-on: https://go-review.googlesource.com/c/go/+/384260 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-04-01all: fix various doc comment formatting nitsRuss Cox
A run of lines that are indented with any number of spaces or tabs format as a <pre> block. This commit fixes various doc comments that format badly according to that (standard) rule. For example, consider: // - List item. // Second line. // - Another item. Because the - lines are unindented, this is actually two paragraphs separated by a one-line <pre> block. This CL rewrites it to: // - List item. // Second line. // - Another item. Today, that will format as a single <pre> block. In a future release, we hope to format it as a bulleted list. Various other minor fixes as well, all in preparation for reformatting. For #51082. Change-Id: I95cf06040d4186830e571cd50148be3bf8daf189 Reviewed-on: https://go-review.googlesource.com/c/go/+/384257 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
2021-11-02runtime, syscall: add calls to asan functionsfanzha02
Add explicit address sanitizer instrumentation to the runtime and syscall packages. The compiler does not instrument the runtime package. It does instrument the syscall package, but we need to add a couple of cases that it can't see. Refer to the implementation of the asan malloc runtime library, this patch also allocates extra memory as the redzone, around the returned memory region, and marks the redzone as unaddressable to detect the overflows or underflows. Updates #44853. Change-Id: I2753d1cc1296935a66bf521e31ce91e35fcdf798 Reviewed-on: https://go-review.googlesource.com/c/go/+/298614 Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: fannie zhang <Fannie.Zhang@arm.com>
2021-06-17[dev.typeparams] runtime/internal/sys: replace BigEndian with ↵Michael Anthony Knyszek
goarch.BigEndian [generated] [git-generate] cd src/runtime/internal/atomic gofmt -w -r "sys.BigEndian -> goarch.BigEndian" . goimports -w *.go cd ../.. gofmt -w -r "sys.BigEndian -> goarch.BigEndian" . goimports -w *.go Change-Id: Iad35d2b367d8defb081a77ca837e7a7c805c2b7b Reviewed-on: https://go-review.googlesource.com/c/go/+/329190 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-05-21[dev.typeparams] runtime: replace funcPC with internal/abi.FuncPCABIInternalCherry Mui
At this point all funcPC references are ABIInternal functions. Replace with the intrinsics. Change-Id: I3ba7e485c83017408749b53f92877d3727a75e27 Reviewed-on: https://go-review.googlesource.com/c/go/+/321954 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-02runtime: make concatstring{2,3,4,5} consistent w/ compiler's useDavid Chase
Internally the compiler uses a0,a1,a3 string, not [3]string, and this lead to different parameter passing (memory, versus registers) which of course did not work. Updates #40724. Change-Id: I1dbf479b88134559ba54b4b00a042b9a0fd128b8 Reviewed-on: https://go-review.googlesource.com/c/go/+/306910 Trust: David Chase <drchase@google.com> Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-08-17runtime: replace index and contains with bytealg callsAustin Clements
The runtime has its own implementation of string indexing. To reduce code duplication and cognitive load, replace this with calls to the internal/bytealg package. We can't do this on Plan 9 because it needs string indexing in a note handler (which isn't allowed to use the optimized bytealg version because it uses SSE), so we can't just eliminate the index function, but this CL does down-scope it so make it clear it's only for note handlers on Plan 9. Change-Id: Ie1a142678262048515c481e8c26313b80c5875df Reviewed-on: https://go-review.googlesource.com/c/go/+/244537 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2020-08-13runtime: revert signal stack mlockingAustin Clements
Go 1.14 included a (rather awful) workaround for a Linux kernel bug that corrupted vector registers on x86 CPUs during signal delivery (https://bugzilla.kernel.org/show_bug.cgi?id=205663). This bug was introduced in Linux 5.2 and fixed in 5.3.15, 5.4.2 and all 5.5 and later kernels. The fix was also back-ported by major distros. This workaround was necessary, but had unfortunate downsides, including causing Go programs to exceed the mlock ulimit in many configurations (#37436). We're reasonably confident that by the Go 1.16 release, the number of systems running affected kernels will be vanishingly small. Hence, this CL removes this workaround. This effectively reverts CLs 209597 (version parser), 209899 (mlock top of signal stack), 210299 (better failure message), 223121 (soft mlock failure handling), and 244059 (special-case patched Ubuntu kernels). The one thing we keep is the osArchInit function. It's empty everywhere now, but is a reasonable hook to have. Updates #35326, #35777 (the original register corruption bugs). Updates #40184 (request to revert in 1.15). Fixes #35979. Change-Id: Ie213270837095576f1f3ef46bf3de187dc486c50 Reviewed-on: https://go-review.googlesource.com/c/go/+/246200 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-04-08cmd/compile,runtime: pass only ptr and len to some runtime callsJosh Bleecher Snyder
Some runtime calls accept a slice, but only use ptr and len. This change modifies most such routines to accept only ptr and len. After this change, the only runtime calls that accept an unnecessary cap arg are concatstrings and slicerunetostring. Neither is particularly common, and both are complicated to modify. Negligible compiler performance impact. Shrinks binaries a little. There are only a few regressions; the one I investigated was due to register allocation fluctuation. Passes 'go test -race std cmd', modulo #38265 and #38266. Wow, does that take a long time to run. Updates #36890 file before after Δ % compile 19655024 19655152 +128 +0.001% cover 5244840 5236648 -8192 -0.156% dist 3662376 3658280 -4096 -0.112% link 6680056 6675960 -4096 -0.061% pprof 14789844 14777556 -12288 -0.083% test2json 2824744 2820648 -4096 -0.145% trace 11647876 11639684 -8192 -0.070% vet 8260472 8256376 -4096 -0.050% total 115163736 115118808 -44928 -0.039% Change-Id: Idb29fa6a81d6a82bfd3b65740b98cf3275ca0a78 Reviewed-on: https://go-review.googlesource.com/c/go/+/227163 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2020-03-05runtime: use staticuint64s instead of staticbytes for 1-length stringsDiogo Pinela
This was the last remaining use of staticbytes, so we can now delete it. The new code appears slightly faster on amd64: name old time/op new time/op delta SliceByteToString/1-4 6.29ns ± 2% 5.89ns ± 1% -6.46% (p=0.000 n=14+14) This may not be the case on the big-endian architectures, since they have to do an extra addition. Updates #37612 Change-Id: Icb84c5911ba025f798de152849992a55be99e4f3 Reviewed-on: https://go-review.googlesource.com/c/go/+/221979 Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-12-05runtime: add a simple version number parserAustin Clements
This will be used to parse the Linux kernel versions, but this code is generic and can be tested on its own. For #35777. Change-Id: If1df48d07250e5855dde45bc9d57c66f777b9fb4 Reviewed-on: https://go-review.googlesource.com/c/go/+/209597 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-06-06runtime: mark all Go symbols called from assembly in other packagesAustin Clements
This marks all Go symbols called from assembly in other packages with "go:linkname" directives to ensure they get ABI wrappers. Now that we have this go:linkname convention, this also removes the abi0Syms definition in the runtime, which was used to give morestackc an ABI0 wrapper. Instead, we now just mark morestackc with a go:linkname directive. This was tested with buildall.bash in the default configuration, with -race, and with -gcflags=all=-d=ssa/intrinsics/off. Since I couldn't test cgo on non-Linux configurations, I manually grepped for runtime symbols in runtime/cgo. Updates #31230. Change-Id: I6c8aa56be2ca6802dfa2bf159e49c411b9071bf1 Reviewed-on: https://go-review.googlesource.com/c/go/+/179862 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2018-10-15cmd/compile: avoid string allocations when map key is struct or array literalMartin Möhrmann
x = map[string(byteslice)] is already optimized by the compiler to avoid a string allocation. This CL generalizes this optimization to: x = map[T1{ ... Tn{..., string(byteslice), ...} ... }] where T1 to Tn is a nesting of struct and array literals. Found in a hot code path that used a struct of strings made from []byte slices to make a map lookup. There are no uses of the more generalized optimization in the standard library. Passes toolstash -cmp. MapStringConversion/32/simple 21.9ns ± 2% 21.9ns ± 3% ~ (p=0.995 n=17+20) MapStringConversion/32/struct 28.8ns ± 3% 22.0ns ± 2% -23.80% (p=0.000 n=20+20) MapStringConversion/32/array 28.5ns ± 2% 21.9ns ± 2% -23.14% (p=0.000 n=19+16) MapStringConversion/64/simple 21.0ns ± 2% 21.1ns ± 3% ~ (p=0.072 n=19+18) MapStringConversion/64/struct 72.4ns ± 3% 21.3ns ± 2% -70.53% (p=0.000 n=20+20) MapStringConversion/64/array 72.8ns ± 1% 21.0ns ± 2% -71.13% (p=0.000 n=17+19) name old allocs/op new allocs/op delta MapStringConversion/32/simple 0.00 0.00 ~ (all equal) MapStringConversion/32/struct 0.00 0.00 ~ (all equal) MapStringConversion/32/array 0.00 0.00 ~ (all equal) MapStringConversion/64/simple 0.00 0.00 ~ (all equal) MapStringConversion/64/struct 1.00 ± 0% 0.00 -100.00% (p=0.000 n=20+20) MapStringConversion/64/array 1.00 ± 0% 0.00 -100.00% (p=0.000 n=20+20) Change-Id: I483b4d84d8d74b1025b62c954da9a365e79b7a3a Reviewed-on: https://go-review.googlesource.com/c/116275 Reviewed-by: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-08-22runtime: replace calls to hasprefix with hasPrefixMartin Möhrmann
The hasprefix function is redundant and can be removed since it has the same implementation as hasPrefix modulo variable names. Fixes #25688 Change-Id: I499cc24a2b5c38d1301718a4e66f555fd138386f Reviewed-on: https://go-review.googlesource.com/115835 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-05-01runtime: use staticbytes in intstring for small vJosh Bleecher Snyder
Triggers 21 times during make.bash. Change-Id: I7efb34200439256151304bb66cd309913f7c9c9e Reviewed-on: https://go-review.googlesource.com/110557 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Martin Möhrmann <moehrmann@google.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-14runtime: don't use floating point in findnull on Plan 9David du Colombier
In CL 98015, findnull was rewritten so it uses bytes.IndexByte. This broke the build on plan9/amd64 because the implementation of bytes.IndexByte on AMD64 relies on SSE instructions while floating point instructions are not allowed in the note handler. This change fixes findnull by using the former implementation on Plan 9, so it doesn't use bytes.IndexByte. Fixes #24387. Change-Id: I084d1a44d38d9f77a6c1ad492773f0a98226be16 Reviewed-on: https://go-review.googlesource.com/100577 Run-TryBot: David du Colombier <0intro@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rob Pike <r@golang.org>
2018-03-09runtime: use bytes.IndexByte in findnullIlya Tocar
bytes.IndexByte is heavily optimized. Use it in findnull. This is second attempt, similar to CL97523. In this version we never call IndexByte on region of memory, that crosses page boundary. A bit slower than CL97523, but still fast: name old time/op new time/op delta GoString-6 164ns ± 2% 118ns ± 0% -28.00% (p=0.000 n=10+6) findnull is also used in gostringnocopy, which is used in many hot spots in the runtime. Fixes #23830 Change-Id: Id843dd4f65a34309d92bdd8df229e484d26b0cb2 Reviewed-on: https://go-review.googlesource.com/98015 Run-TryBot: Ilya Tocar <ilya.tocar@intel.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-01Revert "runtime: use bytes.IndexByte in findnull"Brad Fitzpatrick
This reverts commit 7365fac2dbd01960268ee051ed03d961258d4ef4. Reason for revert: breaks the build on some architectures, reading unmapped pages? Change-Id: I3a8c02dc0b649269faacea79ecd8213defa97c54 Reviewed-on: https://go-review.googlesource.com/97995 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-03-01runtime: use bytes.IndexByte in findnullJosh Bleecher Snyder
bytes.IndexByte is heavily optimized. Use it in findnull. name old time/op new time/op delta GoString-8 65.5ns ± 1% 40.2ns ± 1% -38.62% (p=0.000 n=19+19) findnull is also used in gostringnocopy, which is used in many hot spots in the runtime. Fixes #23830 Change-Id: I2e6cb279c7d8078f8844065de684cc3567fe89d7 Reviewed-on: https://go-review.googlesource.com/97523 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-01runtime: don't allocate to build strings of length 1Josh Bleecher Snyder
Use staticbytes instead. Instrumenting make.bash shows approx 0.5% of all slicebytetostrings have a buffer of length 1. name old time/op new time/op delta SliceByteToString/1-8 14.1ns ± 1% 4.1ns ± 1% -71.13% (p=0.000 n=17+20) SliceByteToString/2-8 15.5ns ± 2% 15.5ns ± 1% ~ (p=0.061 n=20+18) SliceByteToString/4-8 14.9ns ± 1% 15.0ns ± 2% +1.25% (p=0.000 n=20+20) SliceByteToString/8-8 17.1ns ± 1% 17.5ns ± 1% +2.16% (p=0.000 n=19+19) SliceByteToString/16-8 23.6ns ± 1% 23.9ns ± 1% +1.41% (p=0.000 n=20+18) SliceByteToString/32-8 26.0ns ± 1% 25.8ns ± 0% -1.05% (p=0.000 n=19+16) SliceByteToString/64-8 30.0ns ± 0% 30.2ns ± 0% +0.56% (p=0.000 n=16+18) SliceByteToString/128-8 38.9ns ± 0% 39.0ns ± 0% +0.23% (p=0.019 n=19+15) Fixes #24172 Change-Id: I3dfa14eefbf9fb4387114e20c9cb40e186abe962 Reviewed-on: https://go-review.googlesource.com/97717 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2018-02-19runtime: avoid clearing memory during byte slice allocation in gobytesMartin Möhrmann
Avoid using make in gobytes which clears the byte slice backing array unnecessarily since the content is overwritten immediately again. Check that the user provided length is positive and below the maximum allowed allocation size explicitly in gobytes as this was done in makeslice before this change. Fixes #23634 Change-Id: Id852619e932aabfc468871c42ad07d34da91f45c Reviewed-on: https://go-review.googlesource.com/94760 Run-TryBot: Martin Möhrmann <moehrmann@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-02-15runtime: replace _MaxMem with maxAllocAustin Clements
Now that we have memLimit, also having _MaxMem is a bit confusing. Replace it with maxAlloc, which better conveys what it limits. We also define maxAlloc slightly differently: since it's now clear that it limits allocation size, we can account for a subtle difference between 32-bit and 64-bit. Change-Id: Iac39048018cc0dae7f0919e25185fee4b3eed529 Reviewed-on: https://go-review.googlesource.com/85890 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Rick Hudson <rlh@golang.org>
2017-09-22runtime: remove getcallerpc argumentAustin Clements
Now that getcallerpc is a compiler intrinsic on x86 and non-x86 platforms don't need the argument, we can drop it. Sadly, this doesn't let us remove any dummy arguments since all of those cases also use getcallersp, which still takes the argument pointer, but this is at least an improvement. Change-Id: I9c34a41cf2c18cba57f59938390bf9491efb22d2 Reviewed-on: https://go-review.googlesource.com/65474 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
2017-03-08runtime: optimize slicebytestostringJosh Bleecher Snyder
Inline rawstringtmp and simplify. Use memmove instead of copy. name old time/op new time/op delta SliceByteToString/1-8 19.4ns ± 2% 14.1ns ± 1% -27.04% (p=0.000 n=20+17) SliceByteToString/2-8 20.8ns ± 2% 15.5ns ± 2% -25.46% (p=0.000 n=20+20) SliceByteToString/4-8 20.7ns ± 1% 14.9ns ± 1% -28.30% (p=0.000 n=20+20) SliceByteToString/8-8 23.2ns ± 1% 17.1ns ± 1% -26.22% (p=0.000 n=19+19) SliceByteToString/16-8 29.4ns ± 1% 23.6ns ± 1% -19.76% (p=0.000 n=17+20) SliceByteToString/32-8 31.4ns ± 1% 26.0ns ± 1% -17.11% (p=0.000 n=16+19) SliceByteToString/64-8 36.1ns ± 0% 30.0ns ± 0% -16.96% (p=0.000 n=16+16) SliceByteToString/128-8 46.9ns ± 0% 38.9ns ± 0% -17.15% (p=0.000 n=17+19) Change-Id: I422e688830e4a9bd21897d1f74964625b735f436 Reviewed-on: https://go-review.googlesource.com/37791 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Marvin Stenger <marvin.stenger94@gmail.com> Reviewed-by: Keith Randall <khr@golang.org>
2016-11-01runtime: improve atoi implementationMartin Möhrmann
- Adds overflow checks - Adds parsing of negative integers - Adds boolean return value to signal parsing errors - Adds atoi32 for parsing of integers that fit in an int32 - Adds tests Handling of errors to provide error messages at the call sites is left to future CLs. Updates #17718 Change-Id: I3cacd0ab1230b9efc5404c68edae7304d39bcbc0 Reviewed-on: https://go-review.googlesource.com/32390 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-10-28runtime, cmd/compile: rename memclr -> memclrNoHeapPointersAustin Clements
Since barrier-less memclr is only safe in very narrow circumstances, this commit renames memclr to avoid accidentally calling memclr on typed memory. This can cause subtle, non-deterministic bugs, so it's worth some effort to prevent. In the near term, this will also prevent bugs creeping in from any concurrent CLs that add calls to memclr; if this happens, whichever patch hits master second will fail to compile. This also adds the other new memclr variants to the compiler's builtin.go to minimize the churn on that binary blob. We'll use these in future commits. Updates #17503. Change-Id: I00eead049f5bd35ca107ea525966831f3d1ed9ca Reviewed-on: https://go-review.googlesource.com/31369 Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Rick Hudson <rlh@golang.org>
2016-10-28cmd/compile: move stringtoslicebytetmp to the backendMartin Möhrmann
- removes the runtime function stringtoslicebytetmp - removes the generation of calls to stringtoslicebytetmp from the frontend - adds handling of OSTRARRAYBYTETMP in the backend This reduces binary sizes and avoids function call overhead. Change-Id: Ib9988d48549cee663b685b4897a483f94727b940 Reviewed-on: https://go-review.googlesource.com/32158 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-10-17runtime: speed up non-ASCII rune decodingMartin Möhrmann
Copies utf8 constants and EncodeRune implementation from unicode/utf8. Adds a new decoderune implementation that is used by the compiler in code generated for ranging over strings. It does not handle ASCII runes since these are handled directly before calls to decoderune. The DecodeRuneInString implementation from unicode/utf8 is not used since it uses a lookup table that would increase the use of cpu caches. Adds more tests that check decoding of valid and invalid utf8 sequences. name old time/op new time/op delta RuneIterate/range2/ASCII-4 7.45ns ± 2% 7.45ns ± 1% ~ (p=0.634 n=16+16) RuneIterate/range2/Japanese-4 53.5ns ± 1% 49.2ns ± 2% -8.03% (p=0.000 n=20+20) RuneIterate/range2/MixedLength-4 46.3ns ± 1% 41.0ns ± 2% -11.57% (p=0.000 n=20+20) new: "".decoderune t=1 size=423 args=0x28 locals=0x0 old: "".charntorune t=1 size=666 args=0x28 locals=0x0 Change-Id: I1df1fdb385bb9ea5e5e71b8818ea2bf5ce62de52 Reviewed-on: https://go-review.googlesource.com/28490 Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-14cmd/compile: intrinsify slicebytetostringtmp when not instrumentingMartin Möhrmann
when not instrumenting: - Intrinsify uses of slicebytetostringtmp within the runtime package in the ssa backend. - Pass OARRAYBYTESTRTMP nodes to the compiler backends for lowering instead of generating calls to slicebytetostringtmp. name old time/op new time/op delta ConcatStringAndBytes-4 27.9ns ± 2% 24.7ns ± 2% -11.52% (p=0.000 n=43+43) Fixes #17044 Change-Id: I51ce9c3b93284ce526edd0234f094e98580faf2d Reviewed-on: https://go-review.googlesource.com/29017 Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2016-09-08runtime: remove maxstringMartin Möhrmann
Before this CL the runtime prevented printing of overlong strings with the print function when the length of the string was determined to be corrupted. Corruption was checked by comparing the string size against the limit which was stored in maxstring. However maxstring was not updated everywhere were go strings were created e.g. for string constants during compile time. Thereby the check for maximum string length prevented the printing of some valid strings. The protection maxstring provided did not warrant the bookkeeping and global synchronization needed to keep maxstring updated to the correct limit everywhere. Fixes #16999 Change-Id: I62cc2f4362f333f75b77f199ce1a71aac0ff7aeb Reviewed-on: https://go-review.googlesource.com/28813 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-08-30cmd/compile: improve string iteration performanceMartin Möhrmann
Generate a for loop for ranging over strings that only needs to call the runtime function charntorune for non ASCII characters. This provides faster iteration over ASCII characters and slightly faster iteration for other characters. The runtime function charntorune is changed to take an index from where to start decoding and returns the index after the last byte belonging to the decoded rune. All call sites of charntorune in the runtime are replaced by a for loop that will be transformed by the compiler instead of calling the charntorune function directly. go binary size decreases by 80 bytes. godoc binary size increases by around 4 kilobytes. runtime: name old time/op new time/op delta RuneIterate/range/ASCII-4 43.7ns ± 3% 10.3ns ± 4% -76.33% (p=0.000 n=44+45) RuneIterate/range/Japanese-4 72.5ns ± 2% 62.8ns ± 2% -13.41% (p=0.000 n=49+50) RuneIterate/range1/ASCII-4 43.5ns ± 2% 10.4ns ± 3% -76.18% (p=0.000 n=50+50) RuneIterate/range1/Japanese-4 72.5ns ± 2% 62.9ns ± 2% -13.26% (p=0.000 n=50+49) RuneIterate/range2/ASCII-4 43.5ns ± 3% 10.3ns ± 2% -76.22% (p=0.000 n=48+47) RuneIterate/range2/Japanese-4 72.4ns ± 2% 62.7ns ± 2% -13.47% (p=0.000 n=50+50) strings: name old time/op new time/op delta IndexRune-4 64.7ns ± 5% 22.4ns ± 3% -65.43% (p=0.000 n=25+21) MapNoChanges-4 269ns ± 2% 157ns ± 2% -41.46% (p=0.000 n=23+24) Fields-4 23.0ms ± 2% 19.7ms ± 2% -14.35% (p=0.000 n=25+25) FieldsFunc-4 23.1ms ± 2% 19.6ms ± 2% -14.94% (p=0.000 n=25+24) name old speed new speed delta Fields-4 45.6MB/s ± 2% 53.2MB/s ± 2% +16.87% (p=0.000 n=24+25) FieldsFunc-4 45.5MB/s ± 2% 53.5MB/s ± 2% +17.57% (p=0.000 n=25+24) Updates #13162 Change-Id: I79ffaf828d82bf9887592f08e5cad883e9f39701 Reviewed-on: https://go-review.googlesource.com/27853 TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Martin Möhrmann <martisch@uos.de>
generated by cgit v1.3 (git 2.53.0) at 2026-04-15 13:46:36 +0000